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UBC Theses and Dissertations

Socioeconomic and situational factors in urban traffic noise annoyance levels Saur, William Leonard 1975

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S O C I O E C O N O M I C A N D S I T U A T I O N A L F A C T O R S IN U R B A N T R A F F I C NOISE A N N O Y A N C E L E V E L S by W I L L I A M L E O N A R D S A U R B . S . , Massachuset t s Institute of Technology , 1969 A T H E S I S S U B M I T T E D IN P A R T I A L F U L F I L M E N T O F T H E R E Q U I R E M E N T S F O R T H E D E G R E E O F M A S T E R O F A P P L I E D S C I E N C E i n the Department of C i v i l Eng ineer ing We accept this thesis as conforming to the r e q u i r e d s tandard T H E U N I V E R S I T Y O F B R I T I S H C O L U M B I A M a y , 197 5 In p r e s e n t i n g this thesis in p a r t i a l f u l f i l m e n t of the r e q u i r e m e n t s for an advanced degree at the U n i v e r s i t y of B r i t i s h Columbia, I agree that the L i b r a r y s h a l l make it f r e e l y a v a i l a b l e for r e f e r e n c e and study. I f u r t h e r agree that p e r m i s s i o n f o r extensive copying of this thesis f o r s c h o l a r l y purposes may be granted by the Head of my Department or by his r e p r e s e n t a t i v e s . It is understood that copying or p u b l i c a t i o n of this thesis for f i n a n c i a l gain s h a l l not be allowed without my written p e r m i s s i o n . Department of The U n i v e r s i t y of B r i t i s h Columbia Vancouver, Canada i i A B S T R A C T T r a f f i c n oise is having an i n c r e a s i n g l y a d v e r s e impact on the quality of urb a n l i f e . A s a r e s u l t it is n e c e s s a r y f o r community pl a n n e r s and engineers to develop better t r a f f i c management c r i t e r i a and study techniques to keep the l e v e l of community t r a f f i c n o i s e to s o c i a l l y d e s i r a b l e l e v e l s . In the recent past substantial r e s e a r c h has been done to help understand the p h y s i c a l p r o p e r t i e s of t r a f f i c noise and in d i c e s of community noise p e r c e p t i o n . However, l i t t l e i s understood about the p e r c e p t i o n and annoyance l e v e l s of s p e c i f i c groups toward t r a f f i c noise. Complete knowledge of a l l d imensions of t r a f f i c n oise annoyance is n e c e s s a r y f o r the f u r t h e r development of community t r a f f i c management c r i t e r i a and neighborhood planning techniques. The purpose of this r e s e a r c h i s to investigate the dimensions of p u b l i c annoyance to t r a f f i c n oise i n a l a r g e city. S p e c i f i c a l l y , the study objective is to investigate the r e l a t i o n s h i p between noise annoyance i n s e v e r a l urban neighborhoods and the s o c i o e c o n o m i c and s i t u a t i o n a l v a r i a b l e s which have some impact on attitudes about t r a f f i c n o ise. F o l l o w i n g a p r e l i m i n a r y noise annoyance sur v e y of 3 500 house-holds i n Vancouver, B r i t i s h Columbia, a d i s c r i m i n a n t - c l a s s i f i c a t i o n s t a t i s t i c a l technique was used to analyze a follow-up, i n depth, a t t i t u d i n a l s u r v e y o f 3 3 1 h o u s e h o l d s i n s e v e r a l n e i g h b o r h o o d s . T h r e e c a t e g o r i e s o f i n f o r m a t i o n w e r e o b t a i n e d i n t h e s u r v e y : 1 ) a h o u s e h o l d s u r v e y o f a t t i t u d e s t o n o i s e u s i n g a s e m a n t i c d i f f e r e n t i a l s c a l i n g t e c h n i q u e ; 2 ) m e a s u r e s o f t h e s o c i o e c o n o m i c a n d c u l t u r a l p r o f i l e s o f e a c h h o u s e h o l d s u r v e y e d , a n d 3) m e a s u r e s o f t h e p h y s i c a l a n d s i t u a t i o n a l n e i g h b o r h o o d v a r i a b l e s w h i c h w o u l d l i k e l y h a v e s o m e e f f e c t o n t h e n o i s e e n v i r o n m e n t o f t h e h o u s e h o l d . T h e s t a t i s t i c a l m o d e l w a s u s e d t o i n v e s t i g a t e t h e d i m e n s i o n s o f s o c i o e c o n o m i c , c u l t u r a l , a n d p h y s i c a l v a r i a b l e s o n s e p a r a t i n g t h o s e s o c i a l g r o u p i n g s w h i c h w e r e h i g h l y s e n s i t i v e t o t r a f f i c n o i s e f r o m t h o s e w h o w e r e l e s s s e n s i t i v e . R e s u l t s s h o w t h a t t h e r e s p o n d e n t ' s h i g h s o c i o e c o n o m i c s t a t u s i s t h e m a j o r f a c t o r i n n o i s e a n n o y a n c e f o l l o w e d b y t h e d i s t a n c e t h e r e s p o n d e n t l i v e s f r o m m a j o r t r a f f i c a r t e r i e s . P a r t i c u l a r l y , i t a p p e a r s t h a t e d u c a t i o n l e v e l s a r e t h e d o m i n a n t f a c t o r i n t r a f f i c n o i s e a n n o y a n c e . T h e i m p l i c a t i o n o f t h e r e s u l t s o f t h i s r e s e a r c h i s t h a t t r a f f i c m a n a g e m e n t c r i t e r i a m u s t i n c l u d e c o n s i d e r a t i o n o f t h e s o c i o e c o n o m i c a n d c u l t u r a l e n v i r o n m e n t a s w e l l a s a c c e p t e d t r a f f i c p l a n n i n g c r i t e r i a t o m e e t p u b l i c l y a c c e p t a b l e t r a f f i c n o i s e l e v e l s . i v T A B L E O F C O N T E N T S P a g e L i s t o f T a b l e s v i L i s t o f F i g u r e s i x L i s t o f M a p s x L i s t o f E x h i b i t s x i A c k n o w l e d g e m e n t s x i i C H A P T E R I I N T R O D U C T I O N 1 S t a t e m e n t o f P r o b l e m 1 H y p o t h e s i s 2 A s s u m p t i o n s a n d L i m i t a t i o n s 5 R e s e a r c h A p p r o a c h 7 P r e v i e w 8 I I L I T E R A T U R E S U R V E Y C o n t r o l o f N o i s e 9 - a t t h e s o u r c e - o f t r a n s m i s s i o n p a t h - a t t h e r e c e i v e r T r a f f i c N o i s e a n d T r a f f i c C h a r a c t e r i s t i c s 1 4 - J o h n s o n a n d S a u n d e r s - G o r d e n e t . a l . - G a l l o w a y e t . a l . T r a f f i c N o i s e I n d i c e s a n d A n n o y a n c e 1 8 - N e w Y o r k - R o b i n s o n , C o p e l a n d a n d R e n n i e - S t e v e n s , Z w i c k e r a n d K r y t e r - G r i f f i t h s a n d L a n g d o n - J o h n s o n a n d C a r o t h e r s V III DATA REDUCTION AND METHODOLOGY 31 Data Reduction 31 - Socioeconomic variables 32 - Situational variables 45 Methodology 61 - Discriminant-classification analysis 61 - Factor analysis 65 IV ANALYSIS , 7 0 Preliminary Discriminant Analysis 7 0 Discriminant-Classification Analysis 76 - 5 group case 76 - 3 group case 86 - 2 group case 9 0 Factor Analysis 96 Discriminant Analysis Using Factor Scores 103 V RESULTS 111 Research Findings 111 Conclusions 124 Suggestions for Further Research 125 Implications 128 BIBLIOGRAPHY 130 APPENDIX A: DATA 134 APPENDIX B: NOISE, MEASUREMENT, AND INDICES 149 v i L I S T O F T A B L E S T a b l e Page 1 P e a r s o n C o r r e l a t i o n C o e f f i c i e n t s between Selec t e d Indices and M e d i a n D i s s a t i s f a c t i o n S c o r e s 25 2 Socioeconomic V a r i a b l e s 42 3 Situational V a r i a b l e s 46 4 T r a f f i c V o l u m e s and N o i s e L e v e l s — West E n d 49 5 T r a f f i c Volumes and Noi s e L e v e l s - K i t s i l a n o 50 6 T r a f f i c V olumes and Noise L e v e l s - F a i r v i e w / E a s t E n d 51 7 Response to Annoyance Question - West E n d 56 8 Response to Annoyance Question - F a i r v i e w 57 9 Response to Annoyance Question - K i t s i l a n o 58 10 Composite Response to Annoyance Question 59 11 E x a m p l e of F a c t o r Loadings 67 12 F i v e T r i a l D i s c r i m i n a t i n g V a r i a b l e s 71 13 F i v e G roup C l a s s i f i c a t i o n C a t e g o r i e s 7 2 14 T h r e e Group C l a s s i f i c a t i o n C a t e g o r i e s 7 3 15 C o r r e c t C l a s s i f i c a t i o n M a t r i x - 5 Group T r i a l 7 5 16 C o r r e c t C l a s s i f i c a t i o n M a t r i x (1) - 3 Group T r i a l 77 17 C o r r e c t C l a s s i f i c a t i o n M a t r i x (2) - 3 Group T r i a l 7 8 18 Summary of D i s c r i m i n a t i n g V a r i a b l e s C o n s i d e r e d 79 19 C o r r e c t C l a s s i f i c a t i o n M a t r i x (1) - 5 Groups 80 v i i T a b l e 2 0 2 1 2 2 2 3 2 4 2 5 2 6 2 7 2 8 2 9 3 0 3 1 3 2 3 3 3 4 . 3 5 3 6 3 7 3 8 3 9 C o r r e c t C l a s s i f i c a t i o n M a t r i x C o r r e c t C l a s s i f i c a t i o n M a t r i x C o r r e c t C l a s s i f i c a t i o n M a t r i x C o r r e c t C l a s s i f i c a t i o n M a t r i x C o r r e c t C l a s s i f i c a t i o n M a t r i x C o r r e c t C l a s s i f i c a t i o n M a t r i x C o r r e c t C l a s s i f i c a t i o n M a t r i x C o r r e c t C l a s s i f i c a t i o n M a t r i x C o r r e c t C l a s s i f i c a t i o n M a t r i x C o r r e c t C l a s s i f i c a t i o n M a t r i x C o r r e c t C l a s s i f i c a t i o n M a t r i x C o r r e c t C l a s s i f i c a t i o n M a t r i x ( 2 ) - 5 G r o u p s ( 3 ) - 5 G r o u p s ( 4 ) - 5 G r o u p s ( 5 ) - 5 G r o u p s ( 1 ) - 3 G r o u p s ( 2 ) - 3 G r o u p s ( 3 ) - 3 G r o u p s ( 4 ) - 3 G r o u p s ( 1 ) - 2 G r o u p s ( 2 ) - 2 G r o u p s ( 3 ) - 2 G r o u p s ( 4 ) - 2 G r o u p s R o t a t e d F a c t o r M a t r i x a n d C o m m u n a l i t i e s 3 , 5 G r o u p s R o t a t e d F a c t o r M a t r i x a n d C o m r n u n a l i t i e s 2 G r o u p s F a c t o r L o a d i n g s ( 1 ) F a c t o r L o a d i n g s ( 2 ) F a c t o r L o a d i n g s ( 3 ) F a c t o r L o a d i n g s ( 4 ) F a c t o r L o a d i n g s ( 5 ) C o r r e c t C l a s s i f i c a t i o n M a t r i x U s i n g F a c t o r s ( 1 ) - 5 G r o u p s P a g e 8 2 8 3 8 4 8 5 8 7 8 8 8 9 9 1 9 2 9 3 9 4 9 5 9 7 9 8 1 0 0 1 0 0 1 0 1 1 0 1 1 0 2 1 0 4 VIX'l T a b l e Page 40 C o r r e c t C l a s s i f i c a t i o n M a t r i x using F a c t o r s (2) - 5 Groups 105 41 C o r r e c t C l a s s i f i c a t i o n M a t r i x using F a c t o r s - 3 Groups 106 42 C o r r e c t C l a s s i f i c a t i o n M a t r i x using F a c t o r s (1) - 2 Groups 108 43 C o r r e c t C l a s s i f i c a t i o n M a t r i x using F a c t o r s (2) - 2 Groups . 109 44 C o r r e c t C l a s s i f i c a t i o n M a t r i x using F a c t o r s (3) - 2 Groups 110 45 Summary of " B e s t " R e s u l t s 113 46 Means and Standard Deviations of V a r i a b l e s -5 Group C a s e 114 47 Means and Standard Deviations of V a r i a b l e s -3 Group C a s e 116 i x L I S T O F F I G U R E S F i g u r e Page 1 M e a s u r e d Noi s e and T r a f f i c V o l u m e s - West E n d 52 2 M e a s u r e d Noise and T r a f f i c Volumes - K i t s i l a n o 53 3 M e a s u r e d Noise and T r a f f i c V o lumes - F a i r v i e w 54 4 Weighted Sound L e v e l s and Human Responses 60 5 Distance as a F a c t o r i n N o i s e Intensity 153 6 F a l l o f f of Continuous T r a n s p o r t a t i o n N o i s e over Distance 154 7 N o i s e Reduction P r o v i d e d by Various Highway Configurations 155 8 F r e q u e n c y Response of Weighting Networks 156 L I S T O F M A P S Map 1 A r e a s under Study 2 Interview L o c a t i o n s - West E n d 3 N o i s e and T r a f f i c M e a s u r e m e n t L o c a t i o n s -West End. 4 Interview L o c a t i o n s - K i t s i l a n o 5 N o i s e and T r a f f i c M e a s u r e m e n t L o c a t i o n s -K i t s i l a n o 6 Interview L o c a t i o n s - F a i r v i e w (East) 7 Noise and T r a f f i c M e a s u r e m e n t L o c a t i o n s -F a i r v i e w (East) 8 Interview L o c a t i o n s - F a i r v i e w (West) 9 N o i s e and T r a f f i c M e a s u r e m e n t L o c a t i o n s -F a i r v i e w (West) L I S T O F E X H I B I T S E x h i b i t 1 S a m p l e H a r d c o p y o f N o i s e L e v e l s f r o m C h a r t R e c o r d e r A C K N O W L E D G E M E N T S I wish to express my gratitude and thanks to P r o f e s s o r G e r a l d B rown for his guidance and encouragement throughout this t h e s i s . Without his help and thoughtful suggestions and • c r i t i c i s m the p r o j e c t could not have been s u c c e s s f u l l y a c c o m p l i s h e d . I would a l s o l i k e to thank D r . John P r i c e of the Department of A r c h i t e c t u r e both f or his encouragement and his a s s i s t a n c e i n t r a n s c r i b i n g data. F i n a l l y , I would l i k e to thank the Center for T r a n s p o r t a t i o n Studies whose generous financing made the entire study p o s s i b l e . C H A P T E R I I N T R O D U C T I O N Statement of P r o b l e m A n i n c r e a s e d awareness of the p r o b l e m s of noise has been one of the m a j o r aspects of a new c o n c e r n over the environment. P a s t investigations have r e v e a l e d that, not s u r p r i s i n g l y , the p r i m e " d i s t u r b e r " or source of noise i n r e s i d e n t i a l areas and communities appears to be t r a f f i c . A s the standard of l i v i n g r i s e s and an i n c r e a s i n g number of v e h i c l e s moves along our roadways this p r o b l e m w i l l only become greater; therefore, i n o r d e r to deal with t r a f f i c noise and its management i n r e s i d e n t i a l areas, it becomes n e c e s s a r y f o r t r a f f i c managers and planners to under-stand as completely as p o s s i b l e a l l aspects of t r a f f i c noise f r o m its generation to its p e r c e p t i o n by the public. In the past, any undertaking i n the f o r m of new or i m p r o v e d roads on the p a r t of government or planning agencies had only to be concerned with t r a d i t i o n a l t r a f f i c engineering considerations, e.g. the speed and r o a d capacity d e s i r e d . M o r e recently, i n the U.S. , environmental impact statements have been r e q u i r e d as p a r t of the planning p r o c e s s to estimate the adverse effects, if any, on the environment. It i s new efforts along these lines to under-stand and deal with t r a f f i c noise which w i l l need to be made before p r o g r e s s can be attained in reducing the t r a f f i c noise or a l l e v i a t i n g 2 the p r o b l e m s caused by i t . T r a f f i c planners must now be concerned with the o v e r a l l impact of any new f a c i l i t i e s and this must, the r e f o r e , include c o n s i d e r a t i o n of the noise impact. In the recent past, substantial r e s e a r c h has been done to help understand the p h y s i c a l p r o p e r t i e s of t r a f f i c n oise and compile and develop indices of community noise p e r c e p t i o n . However, l i t t l e i s understood about the p e r c e p t i o n and annoyance l e v e l s of s p e c i f i c groups toward t r a f f i c noise. As a result, it has become n e c e s s a r y for engineers and planners to develop newer and better t r a f f i c management c r i t e r i a and study techniques to attain and keep the l e v e l of t r a f f i c noise i n the community to s o c i a l l y acceptable l e v e l s . It is hoped that this t hesis may shed some light on one aspect of the above, v i z . a better understanding of those f a c t o r s which contribute to a community's or individual's awareness of noise. T h e r e f o r e , the purpose of this r e s e a r c h is to investigate the dimensions of annoyance with t r a f f i c noise i n a l a r g e city, Vancouver, B.C. S p e c i f i c a l l y , the study objective is to investigate a number of urban c h a r a c t e r i s t i c s or f a c t o r s and to e s t a b l i s h t h e i r effect upon the individual's p e r c e i v e d l e v e l s of annoyance. Hypothesis A n individual's p e r c e p t i o n of noise depends upon many, c i r c u m s t a n c e s and f a c t o r s . In the r e l a t i v e quiet of the evening, 3 the passage of a single car may become a m a j o r " d i s t u r b e r " of the peace. On the other hand, s e v e r a l m o t o r c y c l e s may d r i v e by and be h a r d l y noticed i n the v i c i n i t y of a noisy c o n s t r u c t i o n site. One member of a f a m i l y may be much more susceptible to the same noise than another member and, f i n a l l y , the same i n d i v i d u a l may give quite different responses to the same noises i f they happen to occur at different t imes or under different c i r c u m s t a n c e s . P r a c t i c a l i t y and t i m e considerations in this t hesis dictated against elaborate attempts to investigate the responses to noise under v a r y i n g c i r c u m s t a n c e s , e. g. t r a f f i c noise o c c u r r i n g late i n the evening vs. that during r u s h hour.' Rather, attention was f o c u s e d on the examination of those f a c t o r s which were felt could affect or contribute to an individual's p e r c e p t i o n of noise i n a f a i r l y d i r e c t manner. Th e s e f a c t o r s or v a r i a b l e s are of many forms; a s o c i o -economic c h a r a c t e r i s t i c such as high income may make an i n d i v i d u a l m o r e aware of his g r e a t e r expectations with r e s p e c t to his e n v i r o n -ment, thus leading h i m to a greater awareness of and s e n s i t i v i t y to noise i n t r u s i o n s . S i m i l a r l y , an older p e r s o n may have become accustomed to a p a r t i c u l a r noise pattern and thus be l e s s s e n s i t i v e to the noise environment. D emographic data such as home or v e h i c l e ownership may a l s o affect one's p e r c e p t i o n of t r a f f i c noise, e.g. the owner or d r i v e r of a m o t o r c y c l e or t r u c k may be f a r l e s s prone to p e r c e i v e t r a f f i c noise as annoying than one who does not 4. own any v e h i c l e s . The p h y s i c a l environment and t r a f f i c c h a r a c t e r i s t i c s them-selves may a l s o play a r o l e i n determining one's p e r c e p t i o n of noise; the e a s i l y v i s i b l e p r e s e n c e of a la r g e s t r e a m of t r a f f i c m oving past one's r e s i d e n c e may alter the p e r c e p t i o n of noise so that the noise f r o m the t r a f f i c s t r e a m seems to be louder than it a c t u a l l y i s . The p r e s e n c e of even a few m o t o r c y c l e s or l a r g e t r u c k s u s u a l l y contributes g r e a t l y to the p e r c e i v e d annoyance no matter how l a r g e the continuous flow of automobile t r a f f i c may be. F i n a l l y , the t r a f f i c noise i t s e l f , as m e a s u r e d objectively by a c a l i b r a t e d m e a s u r i n g device, would c e r t a i n l y s e e m to be a factor; the greater the m e a s u r e d t r a f f i c noise, the greater should be the annoyance indicated. It is obvious, then, that many f a c t o r s exert some influence on the individual's p e r c e p t i o n of t r a f f i c noise. T h e r e f o r e , the following hypothesis has been developed as a focus f o r this r e s e a r c h : "The individual's stated annoyance l e v e l i s a function of the s o c i o e c o n o m i c c h a r a c t e r i s t i c s of the i n d i v i d u a l and of the p h y s i c a l c h a r a c t e r i s t i c s of the t r a f f i c situation. " Thus, the study objective i s to investigate the r e l a t i o n s h i p between noise annoyance i n s e v e r a l urban neighborhoods and the s o c i o -economic and situational v a r i a b l e s which have some impact on attitudes about t r a f f i c n oise. I 5 A s s u m p t i o n s a n d L i m i t a t i o n s S e v e r a l a s s u m p t i o n s a n d l i m i t a t i o n s s h o u l d b e m a d e e x p l i c i t b e f o r e c o n t i n u i n g . T h e a s s u m p t i o n s a r e m a d e b o t h t o l i m i t t h e f a c t o r s u n d e r c o n s i d e r a t i o n a n d t o b e a b l e t o a n a l y z e t h e d a t a i n t h e f o r m i n w h i c h i t w a s c o l l e c t e d . T h e s e a s s u m p t i o n s , o f n e c e s s i t y , p u t c e r t a i n c o n s t r a i n t s o n t h e a n a l y s i s a n d l i m i t t h e s c o p e o f t h e i n v e s t i g a t i o n a n d , t o a c e r t a i n e x t e n t , t h i s i s d e s i r a b l e a s i t e n a b l e s a t i g h t e r f o c u s t o b e b r o u g h t u p o n t h e t o p i c a n d t h e s p e c i f i c f a c t o r s u n d e r c o n s i d e r a t i o n . T h e f o l l o w i n g i s a s u m m a r y o f t h e a s s u m p t i o n s m a d e a n d t h e l i m i t a t i o n s e n c o u n t e r e d : 1 ) T h e p e r c e i v e d a n n o y a n c e c a n b e d e s c r i b e d a n d m e a s u r e d o n a s e m a n t i c d i f f e r e n t i a l L i k e r t s c a l e r a t i n g s y s t e m . T h i s i s a n o r d i n a l r a t i n g s y s t e m i n d i c a t i n g " l e v e l s o f p e r c e i v e d a n n o y a n c e " ( e . g . m i l d l y a n n o y i n g , v e r y a n n o y i n g e t c . ) a n d n o p r e s u m p t i o n i s m a d e t h a t a p a r t i c u l a r l e v e l o f a n n o y a n c e i s a n y f r a c t i o n o r m u l t i p l e o f a n o t h e r l e v e l o f a n n o y a n c e . T h e s u b j e c t i v e r a t i n g g i v e n i s a p a r t i c u l a r i n d i v i d u a l ' s r e s p o n s e t o a p a r t i c u l a r q u e s t i o n . 2) T h e f a c t o r s u n d e r c o n s i d e r a t i o n ( s o c i o e c o n o m i c a n d t r a f f i c r e l a t e d ) w e r e r e s t r i c t e d t o t h o s e v a r i a b l e s w h i c h w e r e f e l t w o u l d c o n t r i b u t e r e a s o n a b l y s i m p l y a n d d i r e c t l y t o e x p l a i n i n g t h e p e r c e p t i o n o f n o i s e a n n o y a n c e a n d t o t h e 6 development of a simple " m e t r i c " which could be u s e d to indicate and d e s c r i b e noise annoyance. Other f a c t o r s could have been brought into c o n s i d e r a t i o n after m o r e extensive work i n data gathering had taken place or if m o r e complex v a r i a b l e s were considered, but it was decided to l i m i t the scope of the investigation by r e s t r i c t i n g the f a c t o r s to those v a r i a b l e s which could be r e l a t i v e l y e a s i l y obtained and m easured. 3) In the p r o c e s s of data coll e c t i o n , measurements of v a r i a b l e s took s e v e r a l g e n e r a l f o r m s . T r a f f i c noise, of its nature, is continuous and can be m e a s u r e d as such. V a r i a b l e s such as age were m o r e e a s i l y grouped into d i s c r e t e segments, e.g. 20-29 ye a r s old. C h a r a c -t e r i s t i c s such as the respondent's sex were coded i n a p u r e l y d i s c r e t e fashion. F i n a l l y , noise p e r c e p t i o n or annoyance can be d e s c r i b e d by the respondent along a continuum, but i s conveniently r e p r e s e n t e d by d i s c r e t e numbers which a r e o r d i n a l in nature and convey only the r e l a t i v e o rder or ranking of the perception. It was a s s u m e d that a l l of these v a r i o u s f o r m s of factor r e p r e s e n t a t i o n s could be used together i n an a n a l y s i s . . 4) The sample study areas were city streets i n r e s i d e n t i a l a r e a s . It was r e c o g n i z e d that these streets were not homogeneous i n nature, i . e. there were i n the sample 7 both a r t e r i a l s and side streets. T hese locations a r e shown on maps i n chapter 3. 5) The t r a f f i c c h a r a c t e r i s t i c s , as measured, were a s s u m e d to be r e p r e s e n t a t i v e of the t r a f f i c situation i n the given a r e a . T h i s q u a l i f i c a t i o n and its l i m i t a t i o n s are m o r e fu l l y d i s c u s s e d i n the appendix on data c o l l e c t i o n . R e s e a r c h A p p r o a c h The p r o b l e m s in v o l v e d i n the a n a l y s i s of p e r c e i v e d annoyance a r e i n determining which f a c t o r s exert the greatest influence: s o c i o e c o n o m i c c h a r a c t e r i s t i c s , t r a f f i c c h a r a c t e r i s t i c s or m e a s u r e d noise. A s it was a l r e a d y known through the surveys and interviews who was annoyed and t h e i r r e l a t i v e l e v e l of annoyance, it was decided to use d i s c r i m i n a n t - c l a s s i f i c a t i o n a n a l y s i s as the s t a t i s t i c a l technique f o r deciding which of the v a r i a b l e s or c h a r a c t e r i s t i c s we ;re most s i g n i f i c a n t i n as s i g n i n g an i n d i v i d u a l to a p a r t i c u l a r group c h a r a c t e r i z e d by a given l e v e l of annoyance. In this way two r e s u l t s would be obtained: f i r s t , only those f a c t o r s which contributed most to the c l a s s i f i c a t i o n and assignment of i n d i v i d u a l s to t h e i r c o r r e c t group would be included (thus e s t a b l i s h i n g these f a c t o r s as dominant over the others i n influencing the p e r c e p t i o n of t r a f f i c noise) and, secondly, some ge n e r a l idea of how important the v a r i a b l e s under c o n s i d e r a t i o n a r e can be gained by a s c e r t a i n i n g what percentage of individuals a r e c o r r e c t l y c l a s s i f i e d , a p o s t e r i o r i , 8 by the d i s c r i m i n a n t - c l a s s if i c a t i o n scheme. A high percentage of c o r r e c t c l a s s i f i c a t i o n and assignment would tend to support the hypothesis that those s o c i o e c o n o m i c and t r a f f i c c h a r a c t e r i s t i c s did influence the individual's e x p r e s s e d annoyance with t r a f f i c n o i s e . A s m a l l percentage of c o r r e c t c l a s s i f i c a t i o n s would indicate that either the v a r i a b l e s under c o n s i d e r a t i o n a r e not those which influence annoyance with t r a f f i c noise or else that the entire hypothesis of annoyance being influenced by such f a c t o r s is wrong. A t h i r d a l t e r n a t i v e may exist i n that e r r o r s may have p r o v i d e d an ina p p r o p r i a t e or inadequate data base on which to p e r f o r m the a n a l y s i s . P r e v i e w Chapter Two w i l l offer a b r i e f summary of the l i t e r a t u r e on the subject. Chapter T h r e e w i l l be concerned with the data c o l l e c t i o n and reduction and the r e s e a r c h methodology. A-summary of the a n a l y s i s w i l l be p r e s e n t e d i n Chapter F o u r and the r e s u l t s of the a n a l y s i s given i n Chapter F i v e . Inaddition to the r e s e a r c h findings, Chapter F i v e contains some i m p l i c a t i o n s of the r e s u l t s and suggestions f o r f u r t h e r r e s e a r c h . F u r t h e r aspects of data c o l l e c t i o n and i n f o r m a t i o n on noise measurement and in d i c e s a r e to be found i n two appendices. 9 C H A P T E R II L I T E R A T U R E S U R V E Y R e s e a r c h i n the a r e a of t r a f f i c noise and its i m p l i c a t i o n s f o r t r a f f i c management and con t r o l has been focused i n appro x i m a t e l y three m a i n areas: the con t r o l of noise, the r e l a t i o n of m e a s u r e d t r a f f i c noise to t r a f f i c composition and ch a r a c t e r i s t i c s , ' and the r e l a t i o n of m e a s u r e d t r a f f i c noise (as c h a r a c t e r i z e d by the establishment of some index) to the p e r c e i v e d annoyance. T h i s study is an offshoot of the l a s t area, v i z . an attempt to rela t e the p e r c e i v e d annoyance on the p a r t of ind i v i d u a l s not p r i m a r i l y to the dist u r b i n g noise but to both the p h y s i c a l environment and s o c i a l c h a r a c t e r i s t i c s of the i n d i v i d u a l . C o n t r o l of Nois e N o i s e c o n t r o l m e a s u r e s m a y b e c l a s s i f i e d into three categories: noise reduction and/or c o n t r o l at the source, c o n t r o l of t r a n s m i s s i o n path, and pr o t e c t i v e m e a s u r e s taken at or by the r e c e i v e r . The two important areas of noise generation a s s o c i a t e d with the v e h i c l e a r e the power plant (gears, intake and exhaust p r o c e s s e s , fans, blowers, s u p e r c h a r g e r s ) and the contact with the r o a d s u r f a c e (tire whine, brake squeal). F o r most motor v e h i c l e s the p r i m a r y noise sources a r e exhaust noises (low frequency) and t i r e noise (higher frequency), the t i r e noise being dominant above 50 mph. 1 0 Exhaust noise, however, i s dominant for dies el t r u cks, buses and m o t o r c y c l e s . The following l i s t s u m m a r i z e s the p r i m a r y methods of noise r e d u c t i o n at the source:^ a) design of the device to produce l i t t l e or no noise. b) i n h i b i t i o n of noise r a d i a t o r s by a b s o r p t i o n m a t e r i a l . c) a l t e r a t i o n of frequency c h a r a c t e r i s t i c s by changing stif f n e s s e s or adding weights to c e r t a i n portions of the s t r u c t u r e . d) e n c l o s u r e or baff l i n g . e) changes i n operating p r o c e d u r e s . f) p r o p e r alignment, maintenance, and lubrication; Short of f o r c i n g v e h i c l e s to be quieter there a r e other methods of reducing noise, i . e. by e f f e c t i v e l y c o n t r o l l i n g or e l i m i n a t i n g the a c c e s s of v e h i c l e s ( e s p e c i a l l y t r u c k s ) to c e r t a i n areas or at c e r t a i n t i m e s . Often this i s done, not for reasons of reducing noise, but to r e l i e v e congestion. E u r o p e has been f a r ahead of N o r t h A m e r i c a i n this r e g a r d . A l e x a n d r e notes that the Common M a r k e t countries have adopted common m a x i m u m p e r m i t t e d noise l e v e l s f o r motor 2 v e h i c l e s and other countries have been following the example. In addition, v e h i c l e s a r e tested before they a r e ever put on the m a r k e t for sale and noise testing has become p a r t of the r e g u l a r maintenance and safety testing p r o c e d u r e s . In some instances separate t r a f f i c n oise p a t r o l s have a l s o been instigated whose job i t i s to apprehend, fine, and i n s u r e compliance of r e p a i r o r d e r s to any v e h i c l e which appears to be too noisy. If the p a t r o l feels that the v e h i c l e i s e x c e s s i v e l y noisy (a subjective a p p r a i s a l as no m e a s u r i n g devices a r e c a r r i e d ) the v e h i c l e is taken to a testing station for objective testing and is not allowed back on the r o a d unless any d e f i c i e n c i e s a r e c o r r e c t e d . C o n t r o l of the t r a n s m i s s i o n path may be a c c o m p l i s h e d i n a number of ways:^ a) I n c r e a s i n g distance: I n c r e a s i n g the distance between the noise source and r e c e i v e r w i l l reduce noise l e v e l s at the r e c e i v e r . b) P a t h deflection: B a r r i e r s can be effective under c e r t a i n conditions in deflecting noise away f r o m the r e c e i v e r . c) E n c l o s u r e : Attenuation may be attained by the use of a p r o p e r l y designed e n c l o s u r e around either the noise s o u r c e or the r e c e i v e r . d) A b s o r p t i o n : A b s o r b i n g m a t e r i a l s i n the path of the noise e f f e c t i v e l y l i m i t the noise r e a c h i n g the r e c e i v e r . In most cases the p r i m a r y and often only r e l i e f is through path deflection of the noise. T h i s is-."'..usually a c c o m p l i s h e d with the use of either a c o u s t i c b a r r i e r s , cut and f i l l sections, or land-scaping. E f f e c t i v e sound b a r r i e r s should be solid, dense, 12 4 impermeable, not l i a b l e to v i b r a t e , and have co n s i d e r a b l e mass. E a r t h mounds and v a r i ous wall b a r r i e r s a r e the u s u a l types. B a r r i e r s a r e of greatest effect if i n s t a l l e d close to either the s o u r c e or r e c e i v e r and should be in the order of 10 feet i n height. 5 6 T h e o r e t i c a l studies of b a r r i e r s by Maekawa and M o o r e have l e d to the development of curves of noise reduction by a b a r r i e r i n t e r m s of its effective height (height above the source), the d i f f r a c t i o n angle over the b a r r i e r (the greater the angle, the g r e a t e r the noise reduction), and the frequency of the noise (higher f r e q u e n c i e s a r e m o r e ef f e c t i v e l y stopped by the b a r r i e r ) . T h e s e 7 t h e o r e t i c a l curves have been m o d i f i e d by Galloway for p r a c t i c a l use in highway design. B a r r i e r s are, i n general, m o r e effective i n reducing automobile noise since the s o u r c e of this noice, p a v e m ent-tire i n t e r a c t i o n , is of high frequency and i s e s s e n t i a l l y at ground l e v e l , thus m a x i m i z i n g the effective height of the b a r r i e r . The t h e o r e t i c a l m a x i m u m effective b a r r i e r reduction i s about 15 dB g f o r c a r s and 10 dB for t r u c k s . 9 M o r e recent p r a c t i c a l studies by H a r m e l i n k , however, have ind i c a t e d that b a r r i e r s a r e not substantially effective. Investigations into the p e r f o r m a n c e of b a r r i e r s along freeways i n O n t a r i o i n d i c a t e d that only moderate (2-4 dBA) reductions i n noise o c c u r r e d at homes near the freeway after the i n s t a l l a t i o n of s e v e r a l types of b a r r i e r s , and no r e l i e f at a l l was found f o r those l i v i n g above the ground l e v e l of a house. It was concluded that effective b a r r i e r s ( i . e. a 8-10 d B A r e d u c t i o n i n m e a s u r e d noise) would have to be over 20 feet high and would be p r o h i b i t i v e l y expensive. The v e r t i c a l displacement of a r o a d to a p o s i t i o n below ground produces a c o u s t i c shielding in much the same manner as a b a r r i e r . Although sections with v e r t i c a l r e t a i n i n g walls achieve greater attenuation than cut sections with sloped embankments, the latt e r u s u a l l y have s e v e r a l advantages i n having g r e a t e r right-of-way, being cheaper, and being better sound a b s o r b e r s (sound would be r e f l e c t e d f r o m a retaining w a l l back into the t r a f f i c stream). The use of bushes, t r e e s , and other foliage is v i r t u a l l y u s e l e s i n the reduction of noise, it being n e c e s s a r y to p r o v i d e roughly 100 to 2 00 feet of 15 foot high t r e e s to achieve a 4 to 5 dB reduction. T h e i r chief values l i e s i n s c r e e n i n g the offending noise f r o m view and offe r i n g p s y c h o l o g i c a l screening. E x a m p l e s of attempts to reduce noise at the r e c e i v e r c o n s i s t of the i n s t a l l a t i o n of building insulation, the use of double windows, ac o u s t i c paneling, or the employment of self generated i n t e r n a l sounds to m a s k extraneous n o i s e s . The above apply p r i m a r i l y to f a c i l i t i e s which a l r e a d y exist i n the v i c i n i t y of noise; if new f a c i l i t i e s a r e to be located i n a s i m i l a r n oisy area, care can be taken to see that a r e a s of p a r t i c u l a r s e n s i t i v i t y to noise be l o c a t e d on the f a r side of the building away f r o m the noise source. In addition, i m p r o v e d building and housing layouts might be designed to m i n i m i z e noise by facing t h e m away f r o m an existing freeway 14 and locating bedrooms on the far side of the s t r u c t u r e . T r a f f i c Noise and T r a f f i c C h a r a c t e r i s t i c s The second m a j o r a r e a of c u r r e n t in v e s t i g a t i o n is that of . re l a t i n g m e a s u r e d t r a f f i c n o i s e to the t r a f f i c c h a r a c t e r i s t i c s , with 12 13 two m a j o r studies by Johnson and Saunders and Galloway et. a l . , being p r i m e contributions i n this a r e a . In a study of f r e e flowing t r a f f i c i n G r e a t B r i t a i n , Johnson and Saunders took roadside noise m e asurements and e m p i r i c a l l y d e r i v e d a model of the noise based on m e a s u r e d c h a r a c t e r i s t i c s . Noise l e v e l s were m e a s u r e d i n d B A and analyzed using a s t a t i s t i c a l d i s t r i b u t i o n a n a l y z e r to determine the true d i s t r i b u t i o n . Not unexpectedly, r e s u l t s i n d i c a t e d that, at distances close to the roadway or at su f f i c i e n t l y low t r a f f i c densities, it i s the noise of i n d i v i d u a l v e h i c l e s that i s observed and that noise l e v e l s d e c r e a s e at 6 dB per doubling of distance as is expected for point s o u r c e s . A t g r e a t e r distances f r o m the roadway and higher t r a f f i c densities, the noise due to i n d i v i d u a l v e h i c l e s tends to s m e a r into a line s o u r c e f r o m which both mean and peak noise l e v e l s d e c r e a s e at 3 dB per doubling of distance. It was a l s o found that the highest and lowest noise l e v e l s were c o n t r o l l e d by i n d i v i d u a l 14 n o i s y v e h i c l e s and by background noise r e s p e c t i v e l y . T h r o u g h a n a l y s i s of these and other f a c t o r s , Johnson and Saunders produced an e m p i r i c a l e x p r e s s i o n f o r the mean noise l e v e l s , i n dBA, f o r f r e e flowing t r a f f i c : 15 where V = t r a f f i c volume (vph) S = speed (mph) D = distance f r o m roadway center l i n e to o b s e r v e r (feet) L = median noise l e v e l (dBA). 50 -The above equation was d e r i v e d f o r a t r a f f i c composition c o n s i s t i n g of 2 0 % t r u c k s but was a s s u m e d v a l i d - 1 dBA for up to 4 0 % t r u c k s . The speed range c o n s i d e r e d was f r o m 3 5 to 55 mph and the above equation obtained by n o r m a l i z i n g to 40 mph. The noise s o u r c e strength of i n d i v i d u a l v e h i c l e s was assumed to v a r y as the fourth power of the speed. A n a l y t i c a l models of both a continuous line s ource and a d i s -c rete source have also been developed and an a l y z e d by Gordon et. a l . F o r flow rates i n excess of 1000 ve h i c l e s per hour the noise l e v e l due to an infinite l i n e source is p r e d i c t e d by The above equation is one of steady state, i . e. there is no s t a t i s t i c a l time d i s t r i b u t i o n of the n o i s e - l e v e l s . The d i s c r e t e source m odel (individual v e h i c l e s ) p r e d i c t s a mean noise l e v e l of 1 6 w h e r e = t r a f f i c d e n s i t y i n v e h i c l e s / m i l e K = a c o n s t a n t T h e d i s c r e t e s o u r c e m o d e l a p p r o a c h e s t h e c o n t i n u o u s l i n e s o u r c e I n c o n t r a s t t o t h e e m p i r i c a l a n d a n a l y t i c a l m o d e l s a b o v e , 1 6 G a l l o w a y e t . a l . h a v e d e v e l o p e d a p r o b a b i l i s t i c s i m u l a t i o n m o d e l i n a n e f f o r t t o o v e r c o m e d r a w b a c k s o f t h e a b o v e m e t h o d s ( e . g . p r e s e n c e o f o n l y u n i f o r m v e h i c l e s p a c i n g , l a c k o f a " s i n g l e l a n e e q u i v a l e n t " f o r m u l t i p l e l a n e s , i n a b i l i t y t o h a n d l e a v a r i e d c o m p o s i t i o n o f v e h i c l e s ) , a n d a l s o t o a v o i d t h e n e c e s s i t y o f b e i n g t i e d t o d a t a o b s e r v a t i o n s f o r e v e r y s i t u a t i o n o r p h e n o m e n o n w h i c h w a s t o b e i n v e s t i g a t e d . I n p u t d a t a c o n s i s t e d o f i n f o r m a t i o n o n r o a d w a y c h a r a c t e r i s t -i c s ( n u m b e r o f l a n e s , l a n e w i d t h ) , d i s t a n c e t o o b s e r v a t i o n p o i n t , t r a f f i c f l o w c h a r a c t e r i s t i c s ( m e a n s p e e d , t r a f f i c m i x , v o l u m e ) , a n d n o i s e l e v e l s p r o d u c e d b y i n d i v i d u a l v e h i c l e s ( d e f i n e d b y o c t a v e b a n d n o i s e s p e c t r a ) . T h e s e t o f n o i s e s o u r c e s ( v e h i c l e s ) a r r a y e d a l o n g a l i n e f o r w h i c h t h e o b s e r v e d n o i s e l e v e l w a s c a l c u l a t e d i s t e r m e d a s n a p s h o t o f h i g h w a y n o i s e c o n d i t i o n s , i . e . a p i c t u r e a t t h a t p o i n t i n t i m e . S u c c e s s i v e s n a p s h o t s w e r e i n d e p e n d e n t s a m p l e s f r o m a p a r t i c u l a r d i s t r i b u t i o n o f n o i s e l e v e l s c h a r a c t e r i s t i c , o f t h e 1 7 g i v e n f l o w a n d s p e e d c o n d i t i o n s . V e h i c l e s w e r e c o n s i d e r e d a s n o i s e s o u r c e s a l o n g a r o a d w a y w i t h a s p e c i f i c f l o w r a t e . T h e a s s u m p t i o n o f a P o i s s o n d i s t r i b u t i o n m o d e l a s 17 of v e h i c l e i n t e r - a r r i v a l times along the roadway ( a good app r o x i m a t i o n for f r e e flowing t r a f f i c ) allows the p r o g r a m m e r to sample randomly f r o m this d i s t r i b u t i o n thus obtaining, after conversion, a set of headways or v e h i c l e spacings approximating that of f r e e flowing t r a f f i c . The positioning of v e h i c l e s along the lanes a l s o takes into effect the p o s i t i o n of the roadway c e n t e r - l i n e and the r e l a t i v e l o c a t i o n of other lanes. The v e h i c l e m i x is obtained by selecting at r a ndom f r o m the d i s t r i b u t i o n r e p r e s e n t i n g the p r o p o r t i o n s of different v e h i c l e s in the total t r a f f i c m i x for that lane. The noise source for the model was obtained by sampling f r o m three r e f e r e n c e spectra, one each f o r autos, heavy d i e s e l t r u c k s , and light t r u c k s . Slight m odifications i n these three b a s i c s p e c t r a enable the model to account for v a r i a t i o n s in noise l e v e l due to different operating conditions, e.g. for a c c e l e r a t i n g c a r s p r o -ducing m o re noise than those at constant v e l o c i t y a noise s p e c t r u m slig h t l y above the n o r m a l r e f e r e n c e s p e c t r u m might be used. P r o p a g a t i o n l o s s e s used were the 6 dB per doubling of distance appropriate for a single source plus s m a l l c o r r e c t i o n s for attenuation due to a b s o r p t i o n and s c a t t e r i n g . The octave band r e f e r e n c e s p e c t r u m for each noise source was adjusted a c c o r d i n g to speed and the distance f r o m the o b s e r v e r . T h e s e adjusted s p e c t r a for each v e h i c l e a r e then summed by frequency band to give that composite s p e c t r u m which would be 1 8 o b t a i n e d a t t h e o b s e r v a t i o n p o i n t a t t h a t i n s t a n t . F i n a l l y , t h e m e a n n o i s e l e v e l i n d B A a n d o t h e r s u m m a r y s t a t i s t i c s a r e c o m p u t e d t o l i n e a r i z e d a p p r o x i m a t i o n o f t h e m e a n n o i s e l e v e l i s t h e s a m e a s t h a t d e r i v e d a n a l y t i c a l l y f o r t h e l i n e s o u r c e : I n c o m p a r i s o n w i t h m e a s u r e d c o n d i t i o n s , G a l l o w a y o b t a i n e d v e r y g o o d a g r e e m e n t u s i n g t h e a b o v e m o d e l ; s o s u c c e s s f u l , i n f a c t , w e r e t h e r e s u l t s t h a t a d e s i g n g u i d e o r " c o o k b o o k " f o r c o m p u t i n g n o i s e f r o m g i v e n c o n d i t i o n s h a s b e e n d e v e l o p e d a s a n o u t g r o w t h o f t h e o r i g i n a l s i m u l a t i o n m o d e l . N o i s e I n d i c e s a n d A n n o y a n c e C e n t r a l t o a l l e f f o r t s a t n o i s e a b a t e m e n t i s t h e n e e d t o r e l a t e s u b j e c t i v e r e s p o n s e t o t h e n o i s e e n v i r o n m e n t t o s o m e r e a d i l y m e a s u r e d a s p e c t o f t h a t e n v i r o n m e n t . P r o g r e s s c a n o n l y b e m a d e a f t e r t h e s e l e c t i o n o f a n a p p r o p r i a t e c r i t e r i o n f o r a s s e s s i n g t h e 1 9 s e v e r i t y o f t h e n o i s e e x p o s u r e . T h i s i n v o l v e s t h e m e a s u r i n g , s c a l i n g , a n d i n d e x i n g o f t h e n o i s e . T h e e a r l i e s t s y s t e m a t i c s o u n d m e a s u r e m e n t s c a r r i e d o u t i n t h e U n i t e d S t a t e s w e r e o f c i t y n o i s e i n N e w Y o r k i n 1 9 2 9 , m o s t o f t h e d a t a b e i n g t a k e n i n t h e f o r m o f m a s k i n g e x p e r i m e n t s , i . e . t o w h a t e x t e n t w a s o n e s o u n d i n t e r f e r e d w i t h o r o v e r w h e l m e d b y c h a r a c t e r i z e t h e n o i s e l e v e l f o r t h e g i v e n s i t u a t i o n . 1 8 T h e 19 another. A second type of observation was a l s o made, however, independent of an observer's ear and y i e l d i n g a p h y s i c a l m e a s u r e -ment of the sound. The acoustimeter, or noise meter, used was s i m i l a r to the m o d e r n sound l e v e l meter but employed only one f r e q u e n c y weighting network which was adjusted to match the 20 F l e t c h e r - M u n s o n equal loudness contours which c l o s e l y r e s e m b l e the A-weighting subsequently adopted i n the f i r s t A m e r i c a n standard sound l e v e l meter. " i f a c e r t a i n meter reading r e s u l t s when a pure tone of 1000 HZ at a sensation l e v e l of 30 units agitates the microphone, then the same meter reading w i l l be obtained for any other pure tone of equal loudness. Starting with any single frequency tone at the intensity just defined, if the l e v e l of the tone i s alter-ed by a chosen amount, say 10 dB, the reading of the n o i s e meter changes 10 dB. It is well known, however, that a change of 10 dB in intensity produces unequal changes in loudness at different frequencies; hence the n oise m e t e r cannot be s a i d to m e a s u r e the loudness of a pure tone at other l e v e l s than that f o r which the weighting network was adjusted. T h e meter does, however, if c a l i b r a t e d a ccordingly, m e a s u r e a p p r o x i m a t e l y the sensation l e v e l of a pure tone i n the frequency r e g i o n f r o m 1000 to 5000 HZ, where the ^weighting curve} . . . is substantially f l a t . "The i n t e r p r e t a t i o n of the m eter reading f o r a complex applied wave i s m o r e involved than f o r a pure tone. The r e c t i f i e r is not a l i n e a r device; the noise meter ^ o e s not] 20 sum up the components of a complex wave i n the same manner as does the ear i n producing loudness. Hence, if two s u c c e s s i v e complex waves differ g r e a t l y in composition, the c o r r e s p o n d i n g meter readings w i l l not compare the waves as they a r e compared by the ear. T h e r e is thus a definitely a r b i t r a r y element in v o l v e d i n the use of a noise m e ter employed in any p a r t i c u l a r survey; another noise meter, having a different single frequency c h a r a c t e r i s t i c . . .and employing a different integrating device, would, i n general, y i e l d different m e asurements. The a r b i t r a r y feature is inevitable, however, as no known apparatus has been constructed capable of imitating the ear i n the integration of the components of a complex wave." It has long been the goal to produce a device that would r e s p o n d to noise signals with readings c l o s e l y c o rresponding to subjective human response. The d i f f i c u l t y of this has been such that the A-weighted l e v e l , f i r s t introduced i n 1935, p e r s i s t s i n c o r r e l a t i n g as well with subjective evaluations of many v a r i e t i e s of noise as the 22 most sop h i s t i c a t e d s c a l e s and p r o c e d u r e s . F o r f u r t h e r d i s c u s s i o n of the A-weighted system, see Appendix B. F u r t h e r c o n f i r m a t i o n of the a c c u r a c y of the A-weighted network 23 came i n I9 60 when Robinson, Copeland and Rennie p e r f o r m e d roadside experiments outside London i n which n o i s i n e s s judgements on p a s s i n g v e h i c l e s were r e l a t e d to the objective readings of sound l e v e l m e t e r s with different frequency weighting networks. L i s t e n e r s were stationed at roadside and asked to judge the n o i s i n e s s of s e l e c t e d p a s s i n g v e h i c l e s on a six step scale ( f r o m quiet to e x c e s s i v e l y noisy). The noise was a l s o m e a s u r e d and r e c o r d e d at the same spot as the l i s t e n e r s and analyzed i n the lab by playing it 21 back through both A and B weighted networks. (The B weighted network is s i m i l a r to the A weighted one but m o r e sensitive to fr e q u e n c i e s below 500 HZ). When a l l v e h i c l e c l a s s e s were grouped together, attempts to f i n d r e l a t i o n s h i p s between the subjective n o i s i n e s s rating given by l i s t e n e r s and the m e a s u r e d value of the noise gave poor r e s u l t s f o r both the A and B weighted networks. G r o u p i n g the v e h i c l e s into c l a s s e s (private c a r s and c o m m e r c i a l v e h i c l e s ) , however, brought out a c l e a r r e l a t i o n s h i p between meas-u r e d noise.levels and i n d i v i d u a l a s s e s s m e n t s of noise f o r each class. It was found that f o r both v e h i c l e c l a s s e s the A-weighted network ou t p e r f o r m e d the B weighted network with c o r r e l a t i o n s of <~ . 9 f o r the A-network v e r s u s *^ ». 8 for the B network. T h e s e r e s u l t s c o mpared f a v o r a b l y with e a r l i e r work of a s i m i l a r nature p e r f o r m e d 24 25 i n S w i t z e r l a n d and the U.S. 26 27 Young, i n s e v e r a l a r t i c l e s , and Galloway et. a l . have a l s o attested to the use of the A-weighted network both because of its consistently respectable c o r r e l a t i o n s with subjective response and its ease and s i m p l i c i t y i n use. 28 Stevens, Zwicker, and K r y t e r have a l l developed m o r e sophi s t i c a t e d but s i m i l a r methods for dealing with complex noise, i . e . r e a l i z i n g that sound, p a r t i c u l a r l y t r a f f i c noise, is broadband i n nature and that the intensity of this noise is not ^uniform a c r o s s the frequency band. A l l methods take into account the masking of one component of a complex noise by the other components. 2 2 F r e q u e n c y b a n d a n a l y s i s o f t h e n o i s e i s p e r f o r m e d a n d l o u d n e s s i n d i c e s d e t e r m i n e d f o r e a c h b a n d . T h e s e c o n t r i b u t i o n s a r e a d d e d t o g e t h e r t o o b t a i n t h e t o t a l l o u d n e s s w i t h v a r i o u s w e i g h t i n g s b e i n g u s e d f o r e a c h b a n d d e p e n d i n g o n . t h e p a r t i c u l a r m e t h o d . A t t e m p t s t o c o m p a r e t h e v a r i o u s i n d i c e s w i t h s u b j e c t i v e r e s p o n s e h a v e m e t w i t h v a r i e d s u c c e s s . M o d i f i c a t i o n s o f t h e b a s i c p r o c e d u r e s a r e c o n t i n u a l l y b e i n g d e v e l o p e d a n d i n c r e a s e d a c c u r a c y h a s b e e n s l o w l y f o r t h c o m i n g o v e r t h e y e a r s . K r y t e r ' s P e r c e i v e d N o i s e L e v e l ( P N L ) , u s e d p r i m a r l y i n c o n n e c t i o n w i t h a i r c r a f t n o i s e , a n d a R o b i n s o n m o d i f i c a t i o n o f S t e v e n s ' M a r k V I c a l c u l a t i o n s a p p e a r t o g i v e b e t t e r 2 9 r e s u l t s t h a n m o s t o t h e r s b u t , i n g e n e r a l , a p p e a r o n l y m a r g i n a l l y b e t t e r t h a n t h e m u s t s i m p l e r A - w e i g h t e d r a t i n g . F u r t h e r i n f o r m a t i o n o n t h e s e r a t i n g s c h e m e s m a y b e f o u n d i n A p p e n d i x B . G r i f f i t h s a n d L a n g d o n ^ c o n d u c t e d a s t u d y i n 1 9 6 7 w i t h t h e o b j e c t o f d e v e l o p i n g a c c e p t a b i l i t y c r i t e r i a f o r t r a f f i c n o i s e i n r e s i d e n t i a l a r e a s . A c o u s t i c m e a s u r e m e n t s w e r e t a k e n a t 1 4 s i t e s i n t h e g r e a t e r L o n d o n a r e a a n d 1 2 0 0 i n t e r v i e w s c o n d u c t e d a m o n g t h e r e s i d e n t s o f t h e s e a r e a s . I n s o f a r a s i t w a s p o s s i b l e c a r e w a s t a k e n t o i n s u r e u n i f o r m i t y o f t h e a r e a s w i t h r e s p e c t t o p h y s i c a l c h a r a c t e r -i s t i c s , i . e . s t r a i g h t r o a d , u n i n t e r r u p t e d t r a f f i c f l o w , n o o t h e r m a j o r n o i s e s o u r c e s . A s i t w a s a l s o d e s i r e d t o s a m p l e d i f f e r e n t e l e m e n t s o f t h e p o p u l a t i o n , r e s i d e n t s f r o m t w o l o c a l h o u s i n g p r o j e c t s w e r e a m o n g t h o s e i n t e r v i e w e d . H e r e t h e p r i m a r y p u r p o s e w a s t o i n s u r e t h a t b o t h o w n e r s a n d r e n t e r s w e r e r e p r e s e n t e d i n t h e s a m p l e . N o 2 3 other s o cioeconomic data was gathered because i n t e r n a l tests had indica t e d they made no different to l e v e l s of s a t i s f a c t i o n with one exception; respondents of l e s s than six months r e s i d e n c e were m o r e s a t i s f i e d with noise l e v e l s than respondents who had been at the site 3 1 longer. A-weighted sound l e v e l measurements were taken over a 2 4 hour p e r i o d outside the house of each interviewee and L L , and L sound l e v e l s were computed where 5 0 9 0 = noise l e v e l (dBA) exceeded 1 0 % of the time L C ( _ = median noise l e v e l (dBA) 50 L ^ Q = noise l e v e l (dBA) exceeded 9 0 % of the time. Interview responses to c e r t a i n questions or statements c o n s i s t e d of indicating a l e v e l of s a t i s f a c t i o n or d i s s a t i s f a c t i o n along a seven point s c a l e . Attempts were then made to c o r r e l a t e the L , L and 10 5 0 l e v e l s with the median d i s s a t i s f a c t i o n s c o r e s as obtained f r o m the i n t e r v i e w s . O v e r a l l r e s u l t s were r e l a t i v e l y poor. M u l t i p l e c o r r e l a t i o n attempts were then undertaken with the hope of i m p r o v i n g the r e s u l t s . T he most significant c o r r e l a t i o n s r e s u l t e d f r o m the c o m p a r i s o n of median d i s s a t i s f a c t i o n s c o r e s with the mean 1 0 % noise l e v e l ( L ) minus . 7 5 of the mean 9 0 % ( L ) l e v e l . G r i f f i t h s 10 9 0 and Langdon then m o d i f i e d this e x p r e s s i o n as per below and t e r m e d it the T r a f f i c Noise Index (TNI): The p a r a m e t e r includes a m e a s u r e of the v a r i a b i l i t y of the noise 24 environment, ( L - L o r,)> and a contribution f r o m the background 10 7 0 le v e l , ( L ). It i s often u s e f u l to think of the L l e v e l coming 7 0 " 0 f r o m the whole s t r e a m of t r a f f i c and the l e v e l f r o m i n d i v i d u a l n o isy v e h i c l e s . P e a r s o n c o r r e l a t i o n coefficients between median d i s s a t i s f a c t i o n s c o r e s and the above mentioned indic e s are shown i n T a b l e 1. When the c o r r e l a t i o n was between the T r a f f i c N o i s e Index and the i n d i v i d u a l s c o r e s as opposed to median s c o r e s the above c o r r e l a t i o n f e l l to .29. Other r e s u l t s of the study were that the t r a f f i c noise was c o n s i d e r e d to be worse i n bad weather and that the m a j o r noise offenders were, i n descending order; m o t o r c y c l e s , t r u c k s and buses, and sports c a r s . L i k e the A-weighted l e v e l , the TNI has maintained support i n t r a f f i c noise studies because it offers ease of ap p l i c a t i o n i n addition to c o r r e l a t i n g w ell with subjective response. 32 Johnston and C a r o t h e r s , i n 197 3, conducted studies to v e r i f y the use of the N o i s e P o l l u t i o n Index ( N P L ) as an acceptable m e a s u r e of subjective annoyance due to t r a f f i c noise h e a r d i n d o o r s . T h e i r experiment was a c o n t r o l l e d one, o c c u r r i n g indoors, and c o n s i s t e d of having volunteers, while in a l e i s u r e environment, l i s t e n to a s e r i e s of si x minute tapes of t r a f f i c noise (of known c h a r a c t e r i s t i c s , i n dBA) and indicate t h e i r r esponse to the p a r t i c u l a r noise on a "not annoying" to " v e r y annoying" scale (index numbers 1 to 9). Attempts at c o r r e l a t i o n were then made between the d i s s a t i s f a c t i o n T A B L E 1 PEARSON CORRELATION COEFFICIENTS B E T W E E N S E L E C T E D INDICES AND MEDIAN DISSATISFACTION SCORES Selected Index  L 1 0 L 5 0 So T N I Median Dissatisfaction .51* .35 .19 .81** Score * p .05 * * p .001 Source: Griffiths and Langdon, p. 5. 26 s c o r e s a n d t h e N P L , w h e r e N P L w a s d e f i n e d a s w h e r e t h e e n e r g y m e a n a n d L ( t ) = t h e n o i s e l e v e l i n d B A a s a f u n c t i o n o f t i m e T = t h e l e n g t h o f t h e p a r t i c u l a r t a p e r u n ( 6 m i n u t e s ) Q* = t h e s t a n d a r d d e v i a t i o n o f t h e n o i s e l e v e l i n d B A k = a c o n s t a n t d e s i g n e d t o o b t a i n m a x i m u m c o r r e l a t i o n w i t h s u b j e c t i v e r e s p o n s e ( t h o u g h t b y R o b i n s o n t o b e a b o u t 2 . 6 ) I n a t t e m p t i n g t o f i n d a n o p t i m a l v a l u e o f k t o m a x i m i z e t h e c o r r e l a t i o n c o e f f i c i e n t s e v e r a l a p p a r e n t l y c o n f l i c t i n g r e s u l t s w e r e o b t a i n e d a s , f o r d i f f e r e n t t r i a l s , v e r y d i f f e r e n t v a l u e s o f k w e r e f o u n d t o g i v e o p t i m u m c o r r e l a t i o n ( c o r r e l a t i o n c o e f f i c i e n t s r a n g e d f r o m . 7 7 t o . 9 6 ) . T h e h i g h v a l u e o f o p t i m u m k w a s 1 0 . 5 w h i l e t h e l o w v a l u e , o b t a i n e d i n s e v e r a l t r i a l s , w a s z e r o . U p o n e x a m i n a t i o n o f t h e d a t a , t h e a u t h o r s o f f e r e d t h e e x p l a n a t i o n t h a t , i n c o n s i d e r i n g a n n o y a n c e r e s p o n s e s t o t r a f f i c n o i s e w h e r e t h e s t a n d a r d d e v i a t i o n s a r e o f t h e o r d e r o f 1 0 d B o r l e s s , t h e r e e x i s t t h r e e r e g i o n s g o v e r n e d b y t h e m e a n n o i s e l e v e l ( L i n t h i s c a s e ) . I n t h e t w o e x t r e m e r e g i o n s (L a b o v e 7 5 - 8 0 e g • V e g d B A o r b e l o w 4 0 - 4 5 d B A ) a n n o y a n c e i s e i t h e r c o n s t a n t l y v e r y h i g h o r e l s e m i n i m a l a n d w o u l d b e i n d e p e n d e n t o f s t a n d a r d d e v i a t i o n s , 27 i . e . of the k <T t e r m . In the center region, . hpweyef', annoyance would depend both on the mean noise and the m e a s u r e of the standard deviation. Johnston and C a r o t h e r s concluded that the N P L worked as w e l l as any other index i n re l a t i n g to subjective response, but that m o re r e s e a r c h was needed into the v a r i a b i l i t y of the "constant" k. The s e i n d i c e s and others not mentioned above a r e d i s c u s s e d b r i e f l y i n Appendix B on the measurement of noise and the fo r m u l a t i o n of i n d i c e s . The Appendix covers s e v e r a l of the m a i n indices but is by no means exhaustive as there a r e almo s t as many in d i c e s as there a r e r e s e a r c h e r s . 2 8 F O O T N O T E S ^ M . D . H a r m e l i n k , " N o i s e a n d V i b r a t i o n C o n t r o l f o r T r a n s -p o r t a t i o n S y s t e m s " , D e p t . o f H i g h w a y s , O n t a r i o , R e p o r t N o .  R R 1 6 8 , O c t o b e r 1 9 7 0 , p . 1 6 . 2 A . A l e x a n d r e , " E u r o p e a n E f f o r t s t o R e d u c e t h e I m p a c t o f T r a f f i c N o i s e " , I n t e r - N o i s e 7 2 C o n f e r e n c e P r o c e e d i n g s , W a s h i n g t o n , D . C . , O c t o b e r 1 9 7 2 , p p . 2 0 5 - 2 0 9 -3 H a r m e l i n k , o p . c i t . , p . 1 9 -4 I b i d . , p . 2 1 . 5 Z. M a e k a w a , " N o i s e R e d u c t i o n b y S c r e e n s " , A p p l i e d  A c o u s t i c s , V o l . 1 , 1 9 6 8 , p p . 1 5 7 - 1 7 3 . 6 J . E . M o o r e , D e s i g n f o r N o i s e R e d u c t i o n , A r c h i t e c t u r e P r e s s , L o n d o n . 7 W . J . G a l l o w a y , W . E . C l a r k , a n d J . S . K e r r i c k , " H i g h w a y N o i s e : M e a s u r e m e n t , S i m u l a t i o n , a n d M i x e d R e a c t i o n s " , • N a t i i n a l C o o p e r a t i v e H i g h w a y R e s e a r c h P r o g r a m R e p o r t N o . 7 8 . , H i g h w a y R e s e a r c h B o a r d , W a s h i n g t o n , D . C , 1 9 6 9 . 8 H a r m e l i n k , o p . c i t . , p . 2 2 . 9 M . D - H a r m e l i n k , a n d J . J . H a j e k , " H i g h w a y N o i s e C o n t r o l " , T r a f f i c E n g i n e e r i n g , V o l . 4 3 , N o . 1 2 , S e p t e m b e r 1 9 7 3 , p p . 4 7 - 5 3 . ^ H a r m e l i n k , l o c . c i t . ^ H a r m e l i n k , l o c . c i t . 1 2 D . R . J o h n s o n , a n d E . G . S a u n d e r s , " T h e E v a l u a t i o n o f N o i s e f r o m F r e e l y F l o w i n g R a o d T r a f f i c " , J o u r n a l o f S o u n d a n d  V i b r a t i o n , V o l . 7 , N o . 2 , 1 9 6 8 , p p . 2 8 7 - 3 0 9 -1 3 G a l l o w a y , o p . c i t . 29 14 C. G. Gordon, W. J. Galloway, B. A. Kugler, and D,. L . Nelson, "Highway Noise: A Design.Guide for E n g i n e e r s " , Na t i o n a l C o o p e r a t i v e Highway R e s e a r c h P r o g r a m Report No. 117. , Highway R e s e a r c h Board, Washington, D. C , 1971. 1 5 I b i d . ^ G a l l o w a y , op. c i t . 17 Ibid., p. 43. 18 Ibid., p. 44. 19 Theodore Schultz, Community Noi s e Ratings,' A p p l i e d Science P u b l i s h e r s L t d . , London, 1972, p. 2. 20 H. F l e t c h e r , and W. A Munson, "Loudness, its Definition, Measurement, and C a l c u l a t i o n " , J o u r n a l of the A c o u s t i c Society  of A m e r i c a , V o l . 5, 1933, pp. 82-108. 2 1 R. H. Gait, "Results of Noise Surveys; P a r t 1: N o i s e out-of-doors", J o u r n a l of the A c o u s t i c Society of A m e r i c a , V o l . 2, 1930, pp. 32-33. 22 Schultz, op. c i t . , p. 15. 23 D. W. Robinson, W. C. Copeland, and A. J. Rennie, "Motor V e h i c l e N o i s e Measurement", The Engineer, V o l . 211, M a r c h 1961. 24 G e r n a l d i r e k t i o n P T T , Switzerland, " F o r s c h u n g s und Versuchsamwalt", R e p o r t No. 22, 637, and Appendix, October 1959. 25 B. Andrews, and D. M. F i n c h , P r o c e e d i n g s , Highway  R e s e a r c h Board, Washington, D. C. , December 1951, p. 456. 26 R. W. Young, i n many studies l i s t e d i n Schultz, op. c i t . , p. 13, repeatedly reminds the r e a d e r that the A-weighted l e v e l p e r s i s t s i n c o r r e l a t i n g a l m o s t as well with subjective evaluations 3 0 o f m a n y v a r i e t i e s o f n o i s e a s t h e m o s t s o p h i s t i c a t e d s c a l e s a n d p r o c e d u r e s . S e e a l s o R . H . P a r k i n , " O n t h e A c c u r a c y o f S i m p l e W e i g h t i n g N e t w o r k s f o r L o u d n e s s E s t i m a t e s o f S o m e U r b a n N o i s e " , J o u r n a l o f S o u n d a n d V i b r a t i o n , V o l . 2 , 1 9 6 4 , p p . 8 6 - 8 8 . 2 7 G a l l o w a y , o p . c i t . , p . 2 5 . 2 8 F o r a f u l l e r d e s c r i p t i o n o f t h e v a r i o u s i n d i c e s d e v e l o p e d b y S t e v e n s , Z w i c k e r , a n d K r y t e r o v e r t h e y e a r s a n d a p a r t i a l l i s t o f t h e i r v a r i o u s p u b l i c a t i o n s , s e e S c h u l t z , o p . c i t . , p p . 1 6 - 2 1 , 3 0 - 3 4 . 2 9 S c h u l t z , o p . c i t . , p . 2 1 . 3 0 I. D . G r i f f i t h s , a n d F . J . L a n g d o n , " S u b j e c t i v e R e s p o n s e t o R o a d T r a f f i c N o i s e " , B u i l d i n g R e s e a r c h S t a t i o n C u r r e n t P a p e r  3 7 / 6 8 , A p r i l 1 9 6 8 . ^ ^ I b i d . , p . 3 . 3 2 G . W . J o h n s o n , a n d R . C a r o t h e r s , " A n n o y a n c e M e a s u r e -m e n t s R e l a t e d t o U r b a n T r a f f i c N o i s e E x p o s u r e " , U n i v e r s i t y o f  T o r o n t o - - Y o r k U n i v e r s i t y J o i n t P r o g r a m i n T r a n s p o r t a t i o n ,  R e s e a r c h R e p o r t N o . 1 3 , 1 9 7 3 . 31 C H A P T E R III D A T A R E D U C T I O N AND M E T H O D O L O G Y  Data Reduction The purpose of the study i s to investigate the r e l a t i o n s h i p between noise annoyance and the s o c i o e c o n o m i c and situational v a r i a b l e s which have some impact on attitudes about t r a f f i c n o ise. In this manner c h a r a c t e r i s t i c s or patterns of c h a r a c t e r i s t i c s can be us e d to explain or dis t i n g u i s h between the v a r i o u s groups who a r e affected d i f f e r e n t l y by t r a f f i c noise. The s t r u c t u r e of this chapter w i l l be to explain b r i e f l y the c o l l e c t i o n and orga n i z a t i o n of data, the methodology adopted, and the p r i n c i p l e s behind those methods used. T h r e e areas of Vancouver were chosen for the study on the b a s i s of r e s u l t s of a pre v i o u s survey. The noise climate i n these a r e a s (see Map 1) had been indicated to be f a i r l y bothersome, and it was felt that respondents i n the three a r e a s (West End, K i t s i l a n o , F a i r v i e w / E a s t EnS) would be repr e s e n t a t i v e of the range of s o c i o -economic v a r i a b l e s to be investigated. The int e r v i e w locations (a one b l o c k section) i n each a r e a numbered about twenty and were s e l e c t e d to simulate as c l o s e l y as p o s s i b l e the average conditions within the area. A total of 331 sets of so c i o e c o n o m i c and annoyance data were gathered while t r a f f i c and noise data were obtained f o r each measurement l o c a t i o n a s s o c i a t e d with the p a r t i c u l a r i n t e r v i e w block. Both i n t e r v i e w and noise measurement locations a r e shown 3 2 o n m a p s 2 t h r o u g h 9 - A l l d a t a w e r e , c o l l e c t e d d u r i n g t h e m i d - d a y h o u r s o f w e e k d a y s i n A u g u s t , 1 9 7 3 . T h e d a t a u s e d f o r t h i s s t u d y c a n b e d i v i d e d i n t o t w o g e n e r a l c a t e g o r i e s ; t h o s e v a r i a b l e s a s s o c i a t e d w i t h t h e i n d i v i d u a l a n d t h o s e a s s o c i a t e d w i t h t h e p h y s i c a l e n v i r o n m e n t . S o c i o e c o n o m i c v a r i a b l e s T h e e i g h t v a r i a b l e s a s s o c i a t e d w i t h t h e i n d i v i d u a l r e s p o n d e n t a r e s o c i o e c o n o m i c i n n a t u r e a n d a r e s h o w n i n T a b l e 2 . A g e a n d s e x a r e b a s i c v a r i a b l e s u s e d i n t h e a n a l y s i s t o d e t e r m i n e i f t h e r e o c c u r s a n y r m r k e d d i f f e r e n c e i n p e r c e p t i o n o f n o i s e e i t h e r o n t h e b a s i s o f s e x ( e . g . t h e h o u s e w i f e , w h o m a y b e h o m e a l l d a y , a s o p p o s e d t o t h e b u s i n e s s m a n , w h o m a y e x p e r i e n c e t h e m i d - d a y r e s i d e n t i a l n o i s e c l i m a t e o n l y o c c a s i o n a l l y ) , o r o n t h e b a s i s o f a g e ( e . g . a r e t h e y o u n g , p e r h a p s u s e d t o a f a s t e r p a c e o f l i f e a n d i t s a c c o m p a n y i n g d i s t r a c t i o n s , l e s s s u s c e p t i b l e t o n o i s e t h a n t h e i r e l d e r s ? ) . T h e f o l l o w i n g c a t e g o r i e s w e r e u s e d t o o b t a i n d a t a o n t h e a g e a n d s e x o f t h e r e s p o n d e n t . S e x : M a l e Q o r F e m a l e £D A g e G r o u p : U n d e r 2 0 Q 5 0 - 5 9 P 2 0 - 2 9 • 6 0 - 6 9 O 3 0 - 3 9 D 7 0 o r o l d e r Q 4 0 - 4 9 • r* 'N * ">••' 7 i M u . J i . , > ' e a! i OO * lp*«>r / i t . 0SHIS 5 iS ' 37 l»o/«l Va«rou«tr • • Y « « M C l u b • • vrp • • • • - - C O R N W A L L - - - - ^ A ^ E , - ^ ^ ^ : , 'PiftST ...nry , HJdion S c h o o l . . SECOND • CIVIC Ii THIRD " AVE. </> 3 2 E FPU RTH F IFTH UJ SIXTH SEVENTH R.C. _ S c n oo I B V / E S T -ElGHTH AVE; W E S T 3 r . j r Vonc'f |w<inr Piilr WEST TENTH pi W E S T AVE, ! T ! IMF" TvT 'WEsY AVE. Lord Ttnnjion ...Schffol.. E L E V E N T H T W E L F T H <4 ! O 5* — co / i I I ' I \,r~... r\ ' r I I i • i o_y E.E.^C r li ^>TsS ?!_ [_5i ;>5or . —•— -Jrsn.s o uT h — — — ^ , , , > X \ V ^ 1/LJ o • I — • ~l -4^  42 T A B L E 2 S O C I O E C O N O M I C V A R I A B L E S A G E : age of the respondent I N C OME: y e a r l y income of the respondent SEX: sex of the respondent E D U C : education l e v e l of the respondent CAROWN: number of ca r s owned in the household OWN/RNT: in d i c a t i o n of whether the respondent owns or rents HOWLNG: indication' of respondent's length of r e s i d e n c y at h i s present address JOB: i n d i c a t i o n of the type of occupation i n which the respondent is employed. 4 3 E d u c a t i o n , i n c o m e a n d o c c u p a t i o n o f t e n c o r r e l a t e h i g h l y w i t h o n e a n o t h e r , s o , t o a c e r t a i n e x t e n t , t h e s e t h r e e v a r i a b l e s a r e s o m e w h a t r e d u n d a n t . A l l a r e u s e d , h o w e v e r , b e c a u s e o f t h e d i f f e r e n c e s i n v o l v e d i n a n i n d i v i d u a l ' s e x p e c t a t i o n s b a s e d o n t h e s e v a r i a b l e s . O c c u p a t i o n s w h i c h p a y r o u g h l y t h e s a m e c a n v a r y c o n s i d e r a b l y i n t h e i r n o i s e e n v i r o n m e n t , e . g . a n o f f i c e j o b a s o p p o s e d t o a f i e l d j o b i n c o n s t r u c t i o n . I t w o u l d t h e n b e e x p e c t e d t h a t i f d i f f e r e n c e s o n t h e p e r c e p t i o n o f n o i s e a r i s e , a l l o t h e r t h i n g s b e i n g e q u a l , t h i s d i f f e r e n c e c o u l d b e a t t r i b u t e d t o t o l e r a n c e s o r f r u s t r a t i o n s a f f i l i a t e d w i t h w o r k i n g a t t h e p a r t i c u l a r j o b . T h o s e w i t h h i g h i n c o m e s o r m o r e e d u c a t i o n m a y f e e l t h e y h a v e e a r n e d t h e r i g h t t o a q u i e t e n v i r o n m e n t a n d t h u s b e q u i t e d i s t r e s s e d a t m o d e r a t e 2 o r l o u d n o i s e l e v e l s i n t h e i r h o m e e n v i r o n m e n t . G a l l o w a y , i n a s t u d y o f s u s c e p t i b i l i t y t o f r e e w a y n o i s e , f o u n d t h a t t h o s e w h o w e r e m o r e a n n o y e d t e n d e d t o b e b e t t e r e d u c a t e d , s o m e w h a t o l d e r , a n d d i d n o t u s e t h e f r e e w a y f o r w o r k ( n o e l e m e n t o f n e c e s s i t y w a s p e r c e i v e d w i t h r e s p e c t t o t h e f r e e w a y ) . T h e a b o v e t h r e e v a r i a b l e s w e r e b r o k e n d o w n a c c o r d i n g t o t h e c a t e g o r i e s g i v e n b e l o w . I n c o m e ( i n d o l l a r s ) : Q U n d e r 2 0 0 0 Q 1 0 , 0 0 0 - 1 1 , 9 9 9 Q 2 0 0 0 - 3 9 9 9 O 1 2 , 0 0 0 - 1 3 , 9 9 9 a 4 0 0 0 - 5 9 9 9 C3 1 4 , 0 0 0 - 1 5 , 9 9 9 a 6 0 0 0 - 7 9 9 9 Q 1 6 , 0 0 0 - 2 0 , 0 0 0 Q 8 0 0 0 - 9 9 9 9 O O v e r 2 0 , 0 0 0 44 E d u c a t i o n L e v e l Attained: Q P u b l i c School D i p l o m a Q High School D i p l o m a O P r o f e s s i o n a l T r a i n i n g Occupational Category: O P r o f e s s i o n a l C3 M a n a g e r i a l O C r a f t s m a n Q Sales, C l e r i c a l O S e c r e t a r i a l C3 J u n i o r C o l l e g e Q U n i v e r s i t y Degree Q P o s t Graduate D e g r e e O Homemaker 0 No E m p l o y e d CD P a r t - t i m e E m p l o y e e 1 I Student Q U n s k i l l e d C a r owners,- because of t h e i r owning a car themselves, may be m o r e i n c l i n e d to t o l e r a t e the t r a f f i c noise of others. In a s i m i l a r fashion, those who do not own c a r s and thus do not contribute to the noise p o l l u t i o n may be i n c l i n e d to be quite s e n s i t i v e . Length of r e s i d e n c y i n the present dwelling and the ownership status of the i n d i v i d u a l (do they own or rent) a l s o m a y be expected to affect the p e r c e p t i o n of noise. C e r t a i n a c c l i m a t i z a t i o n may occur after an i n d i v i d u a l has been exposed to a p a r t i c u l a r noise environment f o r a p e r i o d of time; on the other hand it i s p o s s i b l e that if the i n d i v i d u a l has not adjusted or accommodated h i m s e l f to the n o i s i n e s s , he may become even m ore susceptible and h y p e r s e n s i t i v e over time. Ownership of the dwelling may lead to i n c r e a s e d annoyance because 45 of the i m p l i e d d e c r e a s e i n value or comfort of the home i n the p r e s e n c e of a noisy environment. A renter may not become as annoyed because, i n theory at least, he has the option of moving without a great deal of d i f f i c u l t y or p o s s i b l e l o s s of equity i n the home. V e h i c l e and home ownership status and length of r e s i d e n c y were obtained a c c o r d i n g to the for m a t below. Home Ownership Status: Q Own Q Rent Length of R e s i d e n c y (in years): D Less^than 1 Q 5 - 1 0 Q 1 - 2 a 10 - 15 Q 3 - 5 O over 15 Number of V e h i c l e s Owned: The appropriate number was entered. Situational V a r i a b l e s The c h a r a c t e r i s t i c s a s s o c i a t e d with the p h y s i c a l environment a r e l i s t e d i n Table 3. T h e s e c h a r a c t e r i s t i c s d e s c r i b e the noise environment i n the area, at the t i m e measured, and the p r e s e n c e of f a c t o r s which may a l t e r the p e r c e p t i o n of noise by the i n d i v i d u a l . L n and L are the sound l e v e l s exceeded 10% and 50% of the 10 50 time r e s p e c t i v e l y , as m e a s u r e d i n the A-weighted s y s t e m (units of T A B L E 3 S I T U A T I O N A L V A R I A B L E S 4 6 T N I : t r a f f i c n o i s e i n d e x L i o : n o i s e l e v e l e x c e e d e d 1 0 % o f t h e t i m e ( i n d i c a t i v e o f p e a k s ) L 5 0 : D I S T : m e d i a n n o i s e l e v e l d i s t a n c e b e t w e e n t h e l i s t e n e r ; a n d t h e s t r e e t t h e r e s p o n d e n t i n d i c a t e d w a s n o i s i e s t T O T V E H : t o t a l n u m b e r o f v e h i c l e s p a s t t h e m e a s u r i n g a p p a r a t u s d u r i n g t h e h o u r o f m e a s u r e m e n t T R E E S : i n d i c a t e s p r e s e n c e o r a b s e n c e o f l a r g e t r e e s i n . t h e a r e a B L D G S : i n d i c a t e s p r e s e n c e o r a b s e n c e o f l a r g e b u i l d i n g s i n t h e a r e a F L O W : i n d i c a t e s w h e t h e r t r a f f i c f l o w i s i n t e r r u p t e d o r f r e e f l o w i n g . 47 dBA). L i s i n d i c a t i v e of the "peak" sound l e v e l s and L of the 10 50 median or average sound l e v e l . The T r a f f i c N o i s e Index (TNI) i s a composite index f o r m e d using the values of L and L (the 10 90 sound l e v e l exceeded 9 0 % of the time) and is m o re f u l l y d e s c r i b e d i n Chapter II and Appendix B. A sample hardcopy of the continuous noise l e v e l ' as output on a chart r e c o r d e r is shown below. The distance i n v o l v e d is that approximate distance, in feet, f r o m the center l i n e of the roadway upon which the noise was m e a s u r e d to the house where the interview was made. Dis t a n c e s were estimated using l a r g e scale street maps of the city ( s cale 1" = 200'). The number of v e h i c l e s was the total number of ca r s , t r u c k s , buses and m o t o r c y c l e s to have p a s s e d the m e a s u r i n g apparatus i n both d i r e c t i o n s during the hour i n which noise m e a s u r e -ments were taken. The ranges of noises and volumes of t r a f f i c encountered during the measurement hour are given in T a b l e s 4 through 6. The locations indicated r e f e r to those i l l u s t r a t e d on maps 3, 5, 7 and 9- F i g u r e s 1 through 3 i l l u s t r a t e the range of noise l e v e l s encountered for v a r i o u s t r a f f i c volumes. The flow c h a r a c t e r i s t i c of the t r a f f i c s t r e a m was a two v a l u e d index to differentiate between uni n t e r r u p t e d flow and that which was r e g u l a r l y stopped because of lights, stop signs or frequent p e d e s t r i a n c r o s s i n g s . The p r e s e n c e of l a r g e t r e e s or buildings which could affect the noise path i n the a r e a of noise t r a n s m i s s i o n under c o n c e r n (either through shielding or r e f l e c t i o n effects) was T A B L E 4 T R A F F I C V O L U M E S A N D NOISE L E V E L S - W E S T E N D (a l l f i g u r e s a r e for the one hour measurement period) T r a f f i c C o m p o s i t i o n M e a s u r e d Noise L e v e l s L o c a t i o n Number of ca r s Number of pickups/vans Number of tr u c k s Number of buses Number of mo t o r c y c l e s L50 :, •• L i o . 1 297 29 17 4 65. 0 75.0 2 64 4 8 64. 0 70. 0 3 985 107 42 18 4 72.4 79- 5 4 241 25 16 65.6 74. 3 5 36 2 3 57.7 64.7 6 945 107 37 24 8 75. 1 82. 5 7 710 66 32 1 6 71.7 81. 1 8 695 62 26 23 11 70. 2 79- 2 9 1055 128 41 10 15 71.0 79- 5 10 1015 106 35 3 16 71.3 79- 3 11 235 26 20 7 6 65. 0 76. 8 12 1446 193 60 17 5 73. 5 82. 4 T A B L E 5 T R A F F I C V O L U M E S AND NOISE L E V E L S - K I T S I L A N O (al l f i g u r e s a r e for the one hour measurement period) T r a f f i c C o m p o s i t i o n M e a s u r e d Noise L e v e l s Number of Number of Number of Number of Number of T T L o c a t i o n c a r s pickups/vans t r u c k s buses m o t o r c y c l e s L50 L i o 1 67 0 118 28 12 8 7 0.2 79.7 2 540 31 7 1 7 64. 0 75.3 3 1185 177 52 13 18 67. 2 74. 6 4 1048 117 61 53 16 . 64.7 73. 0 5 763 88 27 9 61.6 71.6 6 637 74 18 19 13 64. 0 75.0 7 107 0 139 36 15 17 65.8 75. 1 8 665 70 14 49 7 64. 0 74. 4 9 925 93 21 17 13 67.6 76.7 10 740 52 13 15 5 59. 2 72. 3 11 107 0 96 44 1 " 9 60. 1 67. 3 12 1040 108 34 66 18 66.5 74.7 13 558 52 14 16 9 63.2 74. 8 14 435 47 12 • • 2 59. 3 70. 4 T A B L E 6 T R A F F I C V O L U M E S A N D N O I S E L E V E L S - F A I R V I E W / E A S T E N D ( a l l f i g u r e s a r e f o r t h e o n e h o u r m e a s u r e m e n t p e r i o d ) -T r a f f i c C o m p o s i t i o n M e a s u r e d N o i s e L e v e l s L o c a t i o n N u m b e r o f c a r s - N u m b e r o f p i c k u p s ; / v a n s N u m b e r o f T r u c k s N u m b e r o f b u s e s N u m b e r o f m o t o r c y c l e s L 5 0 L 1 0 1 2 6 6 4 7 : 1 5 3 5 6 . 1 6 8 . 2 2 1 3 4 8 2 8 9 2 2 1 1 1 7 3 . 6 7 9 . 7 3 1 2 0 0 1 6 8 3 7 2 2 7 0 . 7 7 8 . 8 4 5 6 0 1 2 8 6 6 2 4 5 6 6 . 0 7 4 . 2 5 9 3 5 1 2 4 4 0 1 7 6 6 . 1 7 5 . 5 6 7 1 7 2 1 3 1 7 9 3 8 7 1 . 8 8 1 . 8 7 1 0 0 5 1 2 5 5 4 1 7 1 3 6 3 . 6 7 0 . 4 8 9 4 0 1 4 6 2 8 1 9 6 9 . 3 7 8 . 9 9 1 6 6 5 2 4 4 1 3 8 3 1 3 1 6 6 . 3 7 3 . 9 1 0 3 9 7 8 4 3 2 5 6 0 . 2 7 2 . 2 1 1 1 1 7 0 2 8 7 1 9 7 2 1 5 7 0 . 0 7 6 . 8 1 2 7 9 0 1 0 5 4 5 1 4 6 6 4 . 1 7 3 . 0 1 3 8 8 3 1 5 5 4 5 1 5 7 6 . 1 8 4 . 9 1 4 5 4 7 9 7 3 0 1 7 6 5 4 . 8 6 4 . 1 1 5 2 1 7 2 8 1 7 2 6 1 . 0 7 5 . 0 F i g u r e 1. M e a s u r e d N o i s e and T r a f f i c V o l u m e s West End. ( 5 . 6 % t r u c k s ) /too.J /Seel (-E H t 1 1 — 60 70 £c M e a s u r e d N o i s e (dBA) Range d i s p l a y e d i s f r o m m e d i a n n o i s e l e v e l ' t o the 10 th p e r c e n t i l e l e v e l ( L i n ) . F i g u r e 2. M e a s u r e d N o i s e and T r a f f i c Vo lumes Ki t s i l a n o ( 6 . U t r u c k s ) aooj — i — (oO — ; — 4<r —J— 70 1$ M e a s u r e d N o i s e (dBA) Range d i s p l a y e d i s f r o m m e d i a n n o i s e l e v e l . t o t h e 10th p e r c e n t i l e l e v e l ( L j ^ j ) . —r 60 < L 5 0 > 5 4 F i g u r e 3. M e a s u r e d N o i s e and T r a f f i c Vo lumes F a i r v i e w (8.6% t r u c k s ) /&0D J £ mo J 6oc J —i 1 ~\ 1 1 1 1—• A'S" 6o -70 eo M e a s u r e d N o i s e (dBA) Range d i s p l a y e d i s f r o m m e d i a n n o i s e l e v e l , ( L , - Q ) t o t he 10 th p e r c e n t i l e l e v e l ( L i n ) . a l s o taken into account by distinguishing between those situations i n which l a r g e buildings and t r e e s were pr e s e n t and those i n which they were not. L a s t l y , attitudes toward t r a f f i c noise were c o l l e c t e d as p a r t of the same inte r v i e w s in which the s o c i o e c o n o m i c data was obtained. T h e s e were obtained by asking the interviewee to respond with v a r y i n g degrees of agreement or disagreement with a statement on t r a f f i c noise (see questionnaire i n Appendix A). T h r o u g h the use of semantic d i f f e r e n t i a l L i k e r t s c a l e rating it was p o s s i b l e to attach a number index to an individual's stated annoyance with t r a f f i c noise. T h i s number index would then categorize the i n d i v i d u a l as belonging to a group which was annoyed or unannoyed by t r a f f i c n o i s e to a p a r t i c u l a r extent. A summary of these responses i s given in T a b l e s 7 through 10. In addition, F i g u r e 4 p r e s e n t s a scale of noise r e l a t i n g v a r i o u s sound sources and the g e n e r a l response to them. A l l the above data were c o l l e c t e d during the mid-day hours, 10 A.M. to 4 P.M., during August, 197 3. N o i s e and t r a f f i c data were c o l l e c t e d simultaneously at locations ind i c a t e d in the i n t e r v i e w s to be the p r i n c i p a l sources of t r a f f i c noise i n the a r e a . E r r o r s i n the c o l l e c t i o n and o r g a n i z a t i o n of data a r e f u r t h e r d i s c u s s e d i n Appendix A. 5 6 T A B L E 7 . R E S P O N S E T O A N N O Y A N C E Q U E S T I O N W E S T E N D R e s p o n s e t o s t a t e m e n t t h a t " t r a f f i c n o i s e i n t h e n e i g h b o r h o o d i s a n n o y i n g " ; N u m b e r S t r o n g l y A g r e e d 3 9 M i l d l y A g r e e d 4 5 I n d i f f e r e n t 8 M i l d l y D i s a g r e e d 1 8 S t r o n g l y D i s a g r e e d • ' 9 119 5 7 T A B L E 8 R E S P O N S E T O A N N O Y A N C E Q U E S T I O N F A I R V I E W R e s p o n s e t o s t a t e m e n t t h a t " t r a f f i c n o i s e i n t h e n e i g h b o r h o o d i s a n n o y i n g " . N u m b e r S t r o n g l y A g r e e d 4 2 M i l d l y A g r e e d 2 1 I n d i f f e r e n t 1 3 M i l d l y D i s a g r e e d 1 4 S t r o n g l y D i s a g r e e d 1 1 N o R e p l y 1_ 1 0 2 5 8 T A B L E 9 R E S P O N S E T O A N N O Y A N C E Q U E S T I O N K I T S I L A N O R e s p o n s e t o s t a t e m e n t t h a t " t r a f f i c ! n o i s e i n t h e n e i g h b o r h o o d i s a n n o y i n g . " N u m b e r S t r o n g l y A g r e e d 3 0 M i l d l y A g r e e d 4 0 I n d i f f e r e n t 6 M i l d l y D i s a g r e e d 2 6 S t r o n g l y D i s a g r e e d 8_ 1 1 0 5 9 T A B L E 1 0 R E S P O N S E T O A N N O Y A N C E Q U E S T I O N ( C O M P O S I T E A L L T H R E E A R E A S ) R e s p o n s e t o s t a t e m e n t t h a t " t r a f f i c n o i s e i n t h e n e i g h b o r h o o d i s a n n o y i n g " . N u m b e r % S t r o n g l y A g r e e d 1 1 1 3 3 . 6 M i l d l y A g r e e d 1 0 6 3 2 . 0 I n d i f f e r e n t 2 7 8 . 2 M i l d l y D i s a g r e e d 5 8 1 7 . 5 S t r o n g l y D i s a g r e e d 2 8 8 . 4 N o R e p l y 1 _ 3 3 1 1 0 0 . 0 Sound source dB (A)* T 150 Response criteria Carrier deck jet operation Jet takeoff (200 ft) Discotheque Auto horn (3 ft) Riveting machine Jet takeoff (2000 ft) Shout (0.5 ft) N.Y. subway station Heavy truck (50 ft) Pneumatic drill (50 ft) Freight train (50 ft) Freeway traffic (50 ft) Air conditioning unit (20 ft) Light auto traffic (50 ft) Living room Bedroom Library Soft whisper (15 ft) Broadcasting studio -T 140 130 4- 120 110 + 100 -f 90 4- 80 + 70 60 50 40 30 20 10 J- 0 Painfully loud Limit amplified speech Maximum vocal effort Very annoying Hearing damge (8 hr) Annoying Telephone use difficult Intrusive Quiet Very quiet Just audible Threshold of hearing 'Typical A—Weighted sound levels taken with a sound-level meter and expressed as decibels on the scale. The "A" scale approximates the frequency response of the human ear. F i g u r e k. W e i g h t e d Sound L e v e l s and Human R e s p o n s e S o u r c e : U.S . DOT " R e c o m m e n d a t i o n s f o r N o r t h e a s t C o r r i d o T r a n s p o r t a t i o n , F i n a l R e p o r t " / N T I S , S e p t . 1971 p p . 6 2 - 6 3 . M e t h o d o l o g y T h e b a s i c p u r p o s e o f t h e s t u d y w a s t o d e t e r m i n e w h a t c h a r a c t e r i s t i c s , i f a n y , c o u l d b e u s e d t o u n d e r s t a n d a n d d i s t i n g u i s h a m o n g v a r i o u s a t t i t u d e s t o w a r d t r a f f i c n o i s e . T w o s t a t i s t i c a l m e t h o d s w e r e u s e d i n t h e i n v e s t i g a t i o n , f a c t o r a n a l y s i s a n d d i s c r i m i n a n t c l a s s i f i c a t i o n a n a l y s i s . D i s c r i m i n a n t a n a l y s i s w a s e m p l o y e d i n i t i a l l y i n a n a t t e m p t t o u s e t h e v a r i a b l e s d i s c u s s e d a b o v e t o c l a s s i f y i n d i v i d u a l s i n t o g r o u p s b a s e d o n t h e i r s t a t e d a n n o y a n c e t o w a r d n o i s e a n d t o d i s t i n g u i s h b e t w e e n t h e s e g r o u p s o n t h e b a s i s o f t h e g i v e n c h a r a c t e r i s t i c s . L a t e r , f a c t o r a n a l y s i s w a s u s e d i n a n a t t e m p t t o g r o u p s i m i l a r v a r i a b l e s i n t o a s i n g l e f a c t o r a n d t h u s r e d u c e t h e e f f e c t i v e n u m b e r o f v a r i a b l e s . D i s c r i m i n a n t a n a l y s i s w a s t h e n u s e d a g a i n u s i n g t h e s e f a c t o r s a s t h e n e w " v a r i a b l e s " . D i s c r i m i n a n t - c l a s s i f i c a t i o n a n a l y s i s D i s c r i m i n a n t a n a l y s i s i s a s t a t i s t i c a l t e c h n i q u e t o f a c i l i t a t e t h e c l a s s i f i c a t i o n o f t h i n g s o r p e r s o n s . G i v e n t w o o r m o r e c l a s s e s o f p e r s o n s a n d a s e t o f m e a s u r e m e n t s m a d e o n e a c h p e r s o n w e s e e k a n i n d e x n u m b e r d e r i v e d f r o m t h e s e m e a s u r e m e n t s w h i c h , w h e n a p p l i e d t o s o m e n e w l y o b s e r v e d a n d u n c l a s s i f i e d p e r s o n , w i l l a s s i g n h i m t o o n e o r a n o t h e r o f t h e c l a s s e s w i t h t h e s m a l l e s t p r o b -3 a b i l i t y o f e r r o r . F o r t h e s i m p l e s t c a s e o f c l a s s i f i c a t i o n i n t o t w o g r o u p s t h e p r o c e d u r e f o r d i s c r i m i n a t i n g c o n s i s t s i n f i n d i n g a 62 c r i t i c a l v a l u e o f t h e i n d e x s u c h t h a t a n y i n d i v i d u a l w h o s e c o m p u t e d i n d e x v a l u e o n t h e d i s c r i m i n a n t f u n c t i o n f e l l b e l o w t h e c r i t i c a l v a l u e w o u l d b e c l a s s i f i e d a s b e l o n g i n g t o o n e c l a s s , o t h e r w i s e t o t h e o t h e r c l a s s . T h e p r i n c i p a l d i f f e r e n c e b e t w e e n a d i s c r i m i n a n t f u n c t i o n a n d a n o r d i n a r y l i n e a r r e g r e s s i o n f u n c t i o n a r i s e s f r o m t h e n a t u r e o f t h e d e p e n d e n t v a r i a b l e . A l i n e a r r e g r e s s i o n f u n c t i o n u s e s v a l u e s o f t h e d e p e n d e n t v a r i a b l e t o d e t e r m i n e a l i n e a r f u n c t i o n o f i n d e p e n d e n t v a r i a b l e s t h a t w i l l e s t i m a t e t h e v a l u e s o f t h e d e p e n d e n t v a r i a b l e , w h e r e a s t h e d i s c r i m i n a n t f u n c t i o n p o s s e s s e s n o s u c h v a l u e s o r v a r i a b l e , b u t i n s t e a d u s e s a t w o - w a y c l a s s i f i c a t i o n o f t h e 4 d a t a t o d e t e r m i n e t h e l i n e a r f u n c t i o n . C o n s i d e r a s e t o f k v a r i a b l e s X , , X „ X , b y m e a n s 1 2 k o f w h i c h i t i s d e s i r e d t o d i s c r i m i n a t e b e t w e e n t w o g r o u p s o f i n d i v i d u a l s . L e t b e a l i n e a r c o m b i n a t i o n o f t h e s e v a r i a b l e s . T h e p r o b l e m t h e n i s t o d e t e r m i n e t h e ^ ' s b y m e a n s o f s o m e c r i t e r i o n t h a t w i l l e n a b l e Z t o s e r v e a s a n i n d e x f o r d i f f e r e n t i a t i n g b e t w e e n m e m b e r s o f t h e t w o g r o u p s . B y a d j u s t m e n t s t o t h e V s t h e d i s c r i m i n a t i n g h y p e r -p l a n e , Z , c a n b e a l i g n e d i n s p a c e s u c h t h a t v a l u e s o f Z c o r r e s p o n d -i n g t o t h e g w o g r o u p s w i l l a s s u m e i n c r e a s i n g l y d i v e r g e n t v a l u e s , i . e . t h e d i f f e r e n c e b e t w e e n t h e v a l u e s o f Z f o r t h e t w o g r o u p s w i l l 6 3 b e c o m e g r e a t e r . A t t h e s a m e t i m e , h o w e v e r , v a r i a t i o n s o f t h e v a l u e s o f Z w i t h i n a g r o u p a l s o b e c o m e i n c r e a s i n g l y l a r g e f o r b o t h g r o u p s ; c o n s e q u e n t l y t h e i n c r e a s e i n t h e s e p a r a t i o n o f t h e v a l u e s o f Z f o r t h e t w o g r o u p s o c c u r s a t t h e e x p e n s e o f a n i n c r e a s e i n t h e s e p a r a t i o n o f t h e v a l u e s o f Z w i t h i n e a c h g r o u p . T h i s s i t u a t i o n c o r r e s p o n d s t o t h a t i n w h i c h t h e m e a n s o f t h e t w o d i s t r i b u t i o n s a r e s e p a r a t i n g b u t f o r w h i c h t h e s t a n d a r d d e v i a t i o n s a r e i n c r e a s i n g t o s u c h a n e x t e n t t h a t g r e a t e r d i s c r i m i n a t i o n b e t w e e n t h e t w o d i s t r i b u t i o n s d o e s n o t n e c e s s a r i l y r e s u l t . I t w o u l d b e d e s i r a b l e t o c h o o s e a p l a n e t h a t s e p a r a t e s t h e v a l u e s o f Z f o r t h e t w o g r o u p s a s w i d e l y a s p o s s i b l e r e l a t i v e t o t h e v a r i a t i o n o f t h e v a l u e s o f Z w i t h i n t h e t w o g r o u p s . A s a m e a s u r e o f t h e s e p a r a t i o n o f t h e t w o g r o u p s , i t i s c o n v e n i e n t t o u s e ( Z ^ - Z ^ ) ^ , w h e r e Z ^ a n d Z ^ a r e t h e m e a n s o f t h e t w o g r o u p s . A s a m e a s u r e o f t h e v a r i a t i o n o f t h e v a l u e s o f Z w i t h i n t h e t w o g r o u p s , i t i s c o n v e n i e n t t o u s e w h e r e 2;] d e n o t e s t h e Z v a l u e o f t h e j * * * i n d i v i d u a l i n t h e t*** g r o u p a n d . t h e n u m b e r o f i n d i v i d u a l s i n g r o u p L • T h e n t h e . d e s i r e d p l a n e w i l l b e t h a t f o r w h i c h t h e \ ' s a r e d e t e r m i n e d t o m a x i m i z e t h e f u n c t i o n ( 2.-64 S e t u p i n t h i s w a y , t h e p r o b l e m t h e n c a n b e s o l v e d m a t h e m a t i c a l l y t o o b t a i n t h e v a l u e s o f \ a n d , c o n s e q u e n t l y , t h e d i s c r i m i n a n t 5 f u n c t i o n , Z . H a v i n g d e t e r m i n e d t h e d i s c r i m i n a n t f u n c t i o n , w e m e a s u r e t h e v a l u e s o f t h e c h a r a c t e r i s t i c v a r i a b l e s o f a n e w s u b j e c t a n d c a l c u l a t e h i s s c o r e u s i n g t h e d i s c r i m i n a n t f u n c t i o n . I f h i s s c o r e e x c e e d s a c e r t a i n c u t t i n g s c o r e , u s u a l l y h a l f w a y b e t w e e n t h e m e a n s o f t h e t w o g r o u p s , h e i s a s s i g n e d t o t h a t g r o u p w h i c h h a d t h e h i g h e s t m e a n s c o r e o n t h e d i s c r i m i n a n t f u n c t i o n . T h i s c u t t i n g s c o r e w i l l v a r y d e p e n d i n g o n t h e a p r i o r i p r o b a b i l i t i e s o f a c t u a l l y b e l o n g i n g t o o n e o f t h e g r o u p s . B y a s u i t a b l e c h o i c e o f c u t t i n g p o i n t , t h e o v e r a l l p o s s i b i l i t y o f m i s c l a s s i f i c a t i o n m a y b e m i n i m i z e d . ^ I n m u l t i p l e d i s c r i m i n a n t a n a l y s i s ( m o r e t h a n t w o g r o u p s ) , w e i g h t i n g f a c t o r s ( A ' s ) a r e c a l c u l a t e d f o r e a c h g r o u p e n t e r i n g t h e a n a l y s i s a n d a d i s c r i m i n a n t f u n c t i o n f o r m e d f o r e a c h g r o u p . T h e v a l u e s o f v a r i a b l e s f o r a n e w s u b j e c t a r e t h e n m e a s u r e d a n d a p p l i e d t o e a c h d i s c r i m i n a n t f u n c t i o n a n d t h e s u b j e c t a s s i g n e d t o t h e g r o u p f o r w h i c h h e a t t a i n s t h e h i g h e s t w e i g h t e d s c o r e . I n t h e p r e s e n t c a s e d i s c r i m i n a n t a n a l y s i s w a s u s e d n o t s p e c i f i c a l l y t o c l a s s i f y n e w s u b j e c t s , b u t r a t h e r t o d i s c o v e r w h a t v a r i a b l e s p r o v e d m o s t u s e f u l i n c h a r a c t e r i s t i c s o r p r e d i c t i n g , a p o s t e r i o r i , t h e r e l a t i v e n o i s e a n n o y a n c e f e l t b y i n d i v i d u a l s . 6 5 F a c t o r a n a l y s i s F a c t o r a n a l y s i s i s a s t a t i s t i c a l m e t h o d o f a n a l y z i n g t h e i n t e r c o r r e l a t i o n s w i t h i n a s e t o f o b s e r v a t i o n s o f v a r i a b l e s t o d e t e r m i n e w h e t h e r t h e v a r i a t i o n s r e p r e s e n t e d c a n b e a d e q u a t e l y a c c o u n t e d f o r b y a s m a l l e r n u m b e r o f b a s i c f a c t o r s t h a n w a s u s e d a t t h e s t a r t o f t h e i n v e s t i g a t i o n . T h e p r o b l e m i s t o f i n d a s m a l l a s p o s s i b l e o r t h o g o n a l s e t o f b a s i s v e c t o r s ( f a c t o r s w i t h z e r o c o r r e l a -t i o n b e t w e e n e a c h p a i r ) w h i c h a c c o u n t s f o r m o s t o f t h e v a r i a n c e i n t h e o r i g i n a l s e t o f v a r i a b l e s . F a c t o r a n a l y s i s e n a b l e s o n e t o g r o u p s o m e v a r i a b l e s t o g e t h e r b e c a u s e t h e s e n e w f a c t o r s h o p e f u l l y r e f l e c t 7 s o m e m o r e b a s i c c h a r a c t e r i s t i c s o f t h e o r i g i n a l v a r i a b l e s . T h e f i r s t s t e p i n t h e m o r e c o m m o n R - f a c t o r a n a l y s i s i n v o l v e s t h e c a l c u l a t i o n o f a c o r r e l a t i o n m a t r i x f o r t h e s e t o f i n i t i a l v a r i a b l e s . T h e s e c o n d s t e p i s t o r e d u c e t h e d a t a b y c o n s t r u c t i n g a n e w s e t o f v a r i a b l e s o n t h e b a s i s o f t h e i n t e r r e l a t i o n s e x h i b i t e d i n t h e d a t a . T w o m e t h o d s a r e a v a i l a b l e f o r a c c o m p l i s h i n g t h i s ; c o m m o n f a c t o r a n a l y s i s a n d p r i n c i p a l c o m p o n e n t a n a l y s i s . S i n c e p r i n c i p a l c o m p o n e n t a n a l y s i s w a s u s e d i n t h e p r e s e n t c a s e i t w i l l b e d e s c r i b e d f u r t h e r . P r i n c i p a l c o m p o n e n t a n a l y s i s i s a m e t h o d o f t r a n s f o r m i n g a g i v e n s e t o f v a r i a b l e s i n t o a n e w s e t o f c o m p o s i t e v a r i a b l e s o r p r i n c i p a l c o m p o n e n t s t h a t a r e o r t h o g o n a l o r u n c o r r e l a t e d t o e a c h o t h e r . N o p a r t i c u l a r a s s u m p t i o n a b o u t t h e u n d e r l y i n g s t r u c t u r e o f t h e v a r i a b l e s i s m a d e a s t h e r e i s i n c o m m o n f a c t o r - a n a l y s i s . O n e d e t e r m i n e s t h e b e s t l i n e a r c o m b i n a t i o n o f v a r i a b l e s w h i c h a c c o u n t s 66* f o r m o r e v a r i a n c e i n t h e d a t a t h a n a n y o t h e r l i n e a r c o m b i n a t i o n o f v a r i a b l e s . T h e f i r s t p r i n c i p a l c o m p o n e n t i s t h e s i n g l e b e s t s u m m a r y o f l i n e a r r e l a t i o n s h i p s e x h i b i t e d i n t h e d a t a . T h e s e c o n d c o m p o n e n t i s t h a t l i n e a r c o m b i n a t i o n o f v a r i a b l e s t h a t a c c o u n t s f o r t h e m o s t r e s i d u a l v a r i a n c e a f t e r t h e e f f e c t o f t h e f i r s t c o m p o n e n t i s r e m o v e d , g a n d s o o n f o r s u b s e q u e n t c o m p o n e n t s . E a c h c o m p o n e n t m u s t a l s o b e o r t h o g o n a l ( h a v e z e r o c o r r e l a t i o n ) t o e v e r y o t h e r c o m p o n e n t . S i n c e e a c h c o m p o n e n t i s t h e b e s t l i n e a r s u m m a r y o f v a r i a n c e l e f t i n t h e d a t a a f t e r t h e p r e v i o u s c o m p o n e n t s a r e t a k e n c a r e o f , t h e f i r s t s e v e r a l c o m p o n e n t s w i l l h o p e f u l l y e x p l a i n m o s t o f t h e v a r i a n c e i n t h e d a t a . T h e f i n a l s t e p i n f a c t o r a n a l y s i s i s f a c t o r r o t a t i o n . B y m e a n s o f t h i s r o t a t i o n e a c h f a c t o r i s m a d e a s s i m p l e a n d a s i n t e r p r e t a b l e a s p o s s i b l e , t h e u l t i m a t e g o a l o f a n y r o t a t i o n b e i n g t o o b t a i n s o m e t h e o r e t i c a l l y m e a n i n g f u l f a c t o r s a n d t h e s i m p l e s t f a c t o r s t r u c t u r e . T h e r e a r e t w o t y p e s o f r o t a t i o n : o b l i q u e r o t a t i o n , i n w h i c h t h e f a c t o r s a r e n o t k e p t o r t h o g o n a l , a n d o r t h o g o n a l r o t a t i o n s . V a r i m a x r o t a t i o n , t h e t y p e u s e d i n t h i s s i t u a t i o n , c e n t e r s o n s i m p l i f y i n g t h e c o l u m n s o f a f a c t o r m a t r i x , e q u i v a l e n t t o m a x i m i z i n g t h e v a r i a n c e o f t h e s q u a r e d l o a d i n g s i n e a c h c o l u m n . A s a n e x a m p l e c o n s i d e r T a b l e 1 1 b e l o w . A f t e r r o t a t i o n , v a r i a b l e s A , B , a n d C l o a d q u i t e l a r g e l y o n f a c t o r I I a n d v e r y l i t t l e o n f a c t o r I w h i l e t h e r e v e r s e i s t r u e f o r v a r i a b l e s D a n d E . T h e l o a d i n g s o r n u m b e r s i n a g i v e n r o w 6 7 T A B L E 1 1 E X A M P L E O F F A C T O R L O A D I N G S U n r o t a t e d R o t a t e d V a r i a b l e F a c t o r M a t r i x F a c t o r M a t r i x F a c t o r I F a c t o r I I F a c t o r I F a c t o r I I A . 7 5 . 6 3 . 1 4 . 9 5 B . 6 9 . 5 7 . 1 4 • 9 0 C . 8 0 ' . 4 9 . 1 8 • 9 2 D . 8 5 - . 4 2 • 9 4 • 0 9 E . 7 6 - . 4 2 • 9 2 . 0 7 6 8 r e p r e s e n t r e g r e s s i o n c o e f f i c i e n t s o f f a c t o r s i n d e s c r i b i n g t h e v a r i a b l e s . T h e t o t a l v a r i a n c e o f a v a r i a b l e a c c o u n t e d f o r b y t h e c o m b i n a t i o n o f a l l f a c t o r s i s c a l l e d t h e c o m m u n a l i t y o f t h e v a r i a b l e . T h e c o m m u n a l i t y o f a v a r i a b l e i s t h u s t h a t p r o p o r t i o n o f i t s t o t a l v a r i a n c e w h i c h i s r e p r e s e n t e d i n t h e f a c t o r s p a c e . T h e c o m m u n a l i t y o f v a r i a b l e A i s 2 a n d ( - 9 5 ) o r . 9 0 3 o f t h i s i s e x p l a i n e d b y f a c t o r I I . I n p r i n c i p a l c o m p o n e n t a n a l y s i s t h e i m p o r t a n c e o f a g i v e n f a c t o r i n t e r m s o f t h e a m o u n t o f t o t a l v a r i a n c e i n t h e d a t a i t a c c o u n t s f o r m a y b e o b t a i n e d b y a d d i n g t h e s q u a r e s o f t h e l o a d i n g s i n e a c h c o l u m n . F o r f a c t o r I I , t h i s b e c o m e s + C°iof -r Corf t C.07)1 = J.S7A T h i s n u m b e r i s c a l l e d t h e e i g e n v a l u e f o r f a c t o r I I a n d s i n c e , u s i n g p r i n c i p a l c o m p o n e n t a n a l y s i s , t h e s u m o f a l l e i g e n v a l u e s i s e q u a l t o t h e o r i g i n a l n u m b e r o f v a r i a b l e s , w e h a v e t h e p r o p o r t i o n o f t h e t o t a l v a r i a n c e a c c o u n t e d f o r b y f a c t o r I I i s = . 5 1 5 5 A m o r e d e t a i l e d d i s c u s s i o n o f t h e v a r i o u s t y p e s o f f a c t o r 9 a n a l y s i s m a y b e f o u n d i n e i t h e r R u m m e l o f t h e S t a t i s t i c a l P a c k a g e f o r t h e S o c i a l S c i e n c e s ( S P S S ) c o m p u t e r p r o g r a m m a n u a l . ^ 69 F O O T N O T E S A . J . P r i c e , " A C o m m u n i t y N o i s e S u r v e y o f t h e G r e a t e r V a n c o u v e r R e g i o n a l D i s t r i c t " , E n g i n e e r i n g R e p o r t , B a r r o n a n d  S t r a c h a n , C o n s u l t i n g A c o u s t i c a l E n g i n e e r s , V a n c o u v e r , B . C . 2 W . J . G a l l o w a y , W . E . C l a r k , a n d J . S . K e r r i c k , " H i g h w a y N o i s e : M e a s u r e m e n t s , S i m u l a t i o n , a n d M i x e d R e a c t i o n s " , N a t i o n a l C o o p e r a t i v e H i g h w a y R e s e a r c h P r o g r a m R e p o r t N o . 7 8 , H i g h w a y R e s e a r c h B o a r d , W a s h i n g t o n , D . C , 1 9 6 9 , p . 7 0 . 3 K e i t h H o p e , M e t h o d s o f M u l t i v a r i a t e A n a l y s i s , U n i v e r s i t y o f L o n d o n P r e s s L t d . , L o n d o n , 1 9 6 8 , p . 1 0 2 . 4 P a u l G . H o e l , I n t r o d u c t i o n t o M a t h e m a t i c a l S t a t i s t i c s , J o h n W i l e y a n d S o n s I n c . , N e w Y o r k , 1 9 5 4 , p . 1 8 0 . 5 I b i d . , p . 1 8 1 . 6 H o p e , o p . c i t . , p . 1 0 6 . 7 F o r a m o r e c o m p r e h e n s i v e d i s c u s s i o n o f f a c t o r a n a l y s i s s e e e i t h e r R . J . R u m m e l , " U n d e r s t a n d i n g F a c t o r A n a l y s i s " , J o u r n a l o f C o n f l i c t R e s o l u t i o n , V o l . I I , N o . 4 , D e c e m b e r 1 9 6 7 , p p . 4 4 4 - 4 8 0 , o r N o r m a n N i e , D a l e B e n t , a n d C H a d l a i H u l l , S t a t i s t i c a l P a c k a g e f o r t h e S o c i a l S c i e n c e s ( S P S S ) , M c G r a w - H i l l B o o k C o m p a n y , N e w Y o r k , 1 9 7 0 , p p . 2 0 8 - 2 4 4 . g N i e , o p . c i t . , p . 2 1 0 . 9 R u m m e l , o p . c i t . ^ N i e , b p . c i t . 7 0 C H A P T E R I V A N A L Y S I S A l l a n a l y s e s d i s c u s s e d i n t h i s c h a p t e r t o o k p l a c e a t t h e U n i v e r s i t y o f B r i t i s h C o l u m b i a c o m p u t i n g c e n t e r a n d t w o p r o g r a m s o f t h e U n i v e r s i t y w e r e u s e d i n t h e a n a l y s i s ( U B C F A C T O , t h e f a c t o r a n a l y s i s p r o g r a m , a n d B M D 0 7 M , t h e d i s c r i m i n a n t a n a l y s i s p r o g r a m ) . T h e a n a l y s e s o f t h e d a t a o c c u r r e d i n s e v e r a l p h a s e s . I n i t i a l l y , d i s c r i m i n a n t a n a l y s i s w a s r u n u s i n g o n l y a f e w t e s t v a r i a b l e s t o o b t a i n s o m e p r e l i m i n a r y i n f o r m a t i o n a s t o h o w t h e p r o c e s s w a s w o r k i n g . T h e s e v a r i a b l e s a r e l i s t e d i n T a b l e 1 2 a n d t h e r e s u l t s o f t h e a b o v e a n a l y s i s w e r e i n c o n c l u s i v e . T w o s e p a r a t e a t t e m p t s a t d i s c r i m i n a n t - c l a s s i f i c a t i o n w e r e m a d e , o n e i n t o f i v e g r o u p s a n d t h e o t h e r i n t o t h r e e g r o u p s a s p e r T a b l e s 1 3 a n d 1 4 . T h e a c t u a l n u m b e r i n e a c h c l a s s i f i c a t i o n w a s k n o w n o n t h e b a s i s o f t h e r e s p o n s e t o t h e s t a t e m e n t " T h e n o i s e f r o m t r a f f i c i n t h i s n e i g h b o r h o o d i s a n n o y i n g " , a n d t h e s e a r e g i v e n i n T a b l e s 7 t h r o u g h 9 o f C h a p t e r I I I . A s c a n b e s e e n f r o m T a b l e 1 0 i n C h a p t e r I I I , t h e m a j o r i t y o f r e s p o n d e n t s i n d i c a t e d a n n o y a n c e w i t h t r a f f i c n o i s e i n t h e c o m m u n i t y t o s o m e e x t e n t . T h i s w e i g h t i n g i n f a v o r o f t h o s e a n n o y e d r e f l e c t s a b a s i c a s s u m p t i o n o f t h e i n v e s t i g a t i o n i n c h o o s i n g a s s t u d y a r e a s t h o s e s e c t i o n s w h i c h h a d i n d i c a t e d i n p r e v i o u s s u r v e y s t h a t t r a f f i c n o i s e w a s a p r o b l e m . A c c o r d i n g l y , t h e a n n o y a n c e r e s p o n s e s w e r e a c c e p t e d a s r e p r e s e n t i n g a v a l i d s a m p l e o f o p i n i o n i n t h o s e p a r t i c u l a r T A B L E 1 2 F I V E T R I A L D I S C R I M I N A T I N G V A R I A B L E S O W N / R N T H O W L N G A G E T N I I N C O M E d e f i n i t i o n s o f t h e a b o v e v a r i a b l e s m a y b e f o u n d i n T a b l e s 2 a n d 3 . 7 2 T A B L E 1 3 F I V E G R O U P C L A S S I F I C A T I O N C A T E G O R I E S 1 = s t r o n g l y d i s a g r e e d 2 = m i l d l y d i s a g r e e d 3 = n e i t h e r a g r e e d n o r d i s a g r e e d ( i n d i f f e r e n t ) 4 = m i l d l y a g r e e d 5 = s t r o n g l y a g r e e d T A B L E 1 4 T H R E E G R O U P C L A S S I F I C A T I O N C A T E G O R I E S A = d i s a g r e e d = 1 a n d 2 B = i n d i f f e r e n t = 3 C = a g r e e d = 4 a n d 5 a r e a s . H a d t h e r e b e e n a p r i o r i k n o w l e d g e t h a t t h e r e s p o n s e s o b t a i n e d w e r e u n r e p r e s e n t a t i v e o f o p i n i o n i n t h e a r e a , w e i g h t i n g f a c t o r s c o u l d h a v e b e e n a p p l i e d t o t h e s a m p l e n u m b e r i n e a c h g r o u p t o r e f l e c t t h i s p r i o r k n o w l e d g e . S i n c e i t w a s f e l t t h a t t h e s a m p l e n u m b e r s w e r e r e p r e s e n t a t i v e , a w e i g h t i n g o f u n i t y f o r e a c h g r o u p w a s a s s u m e d . I n t h e a t t e m p t s a t c l a s s i f y i n g i n d i v i d u a l s i n t o f i v e g r o u p s h o n e o f t h e f i v e v a r i a b l e s i n T a b l e 1 2 w a s s i g n i f i c a n t a t t h e 5 % l e v e l o f s i g n i f i c a n c e , a n d a t t h e 1 0 % l e v e l o f s i g n i f i c a n c e A G E a n d T N I t o g e t h e r w e r e a b l e t o c l a s s i f y c o r r e c t l y o n l y 1 4 . 9 % o f t h e s u b j e c t s . G r e a t e s t s u c c e s s w a s i n c l a s s i f y i n g t h o s e w h o w e r e i n d i f f e r e n t o r s t r o n g l y d i s a g r e e d , w h e r e a l m o s t 5 0 % w e r e c o r r e c t l y c l a s s i f i e d . R e s u l t s a r e s h o w n i n T a b l e 1 5 . I t w a s t h e n d e c i d e d t o a t t e m p t c l a s s i f i c a t i o n s i n t o o n l y t h r e e g r o u p s b y c o m b i n i n g t h o s e g r o u p s w h i c h b a s i c a l l y a g r e e d o r d i s -a g r e e d w i t h t h e s t a t e m e n t o n n o i s e a s i n d i c a t e d i n T a b l e 1 4 . A t t h e 5 % l e v e l o f s i g n i f i c a n c e A G E w a s t h e f i r s t t o e n t e r a s a d i s c r i m i n a -t i n g v a r i a b l e r e s u l t i n g i n 1 9 - 4 % c o r r e c t c l a s s i f i c a t i o n s a n d b e i n g m o s t s u c c e s s f u l i n c l a s s i f y i n g t h o s e w h o w e r e e i t h e r n o t a n n o y e d ( d i s a g r e e d w i t h t h e s t a t e m e n t ) o r i n d i f f e r e n t . L e s s t h a n 1 % o f t h o s e a n n o y e d w e r e c o r r e c t l y c l a s s i f i e d , h o w e v e r . T h e a d d i t i o n o f t h e v a r i a b l e O W N / R N T t o t h e d i s c r i m i n a n t f u n c t i o n i n c r e a s e d t h e p e r c e n t a g e o f c o r r e c t c l a s s i f i c a t i o n s t o 2 8 . 5 % , i n c r e a s i n g t h e p e r c e n t a g e o f t h o s e a n n o y e d w h o w e r e c o r r e c t l y c l a s s i f i e d t o 2 4 % 7 5 T A B L E 1 5 C O R R E C T C L A S S I F I C A T I O N M A T R I X - F I V E G R O U P T R I A L N u m b e r o f c a s e s c l a s s i f i e d i n t o g r o u p s -N O T A N Y G r o u p M L D N O T I N D I F F M L D A N Y V E R Y A N N O T A N Y 1 4 6 7 0 1 M L D N O T 2 2 1 2 1 7 6 1 1 I N D I F F 6 4 1 2 4 1 M L D A N Y 2 7 2 7 3 8 1 1 3 V E R Y A N 3 0 2 0 6 1 0 0 % o f c a s e s c l a s s i f i e d i n t o e a c h g r o u p -N O T A N Y M L D N O T I N D I F F M L D A N Y V E R Y A N T O T A L G r o u p N O T A N Y 5 0 . 0 0 2 1 . 4 3 2 5 . 0 0 0 0 . 0 0 3 . 5 7 2 8 . 0 0 M L D N O T 3 7 . 9 3 • 2 0 . 6 9 2 9 . 3 1 1 0 . 3 4 1 7 2 5 8 . 0 0 I N D I F F 2 2 . 2 2 1 4 . 8 1 4 4 . 4 4 1 4 . 8 1 3 . 7 0 2 7 . 0 0 M L D A N Y 2 5 . 4 7 2 5 . 4 7 3 5 . 8 5 1 0 3 8 2 . 8 3 1 0 6 . 0 0 V E R Y A N 2 7 . 0 3 1 8 . 0 2 5 4 . 9 5 0 0 . 0 0 0 . 0 0 1 1 1 . 0 0 C o r r e c t c l a s s i f i c a t i o n m a t r i x ; 5 g r o u p s D i s c r i m i n a t i n g v a r i a b l e s ; A G E , T N I L e v e l o f s i g n i f i c a n c e : 1 0 % 1 4 . 8 5 % o f t h e c a s e s w e r e c o r r e c t l y c l a s s i f i e d b u t d e c l i n i n g i n t h e a b i l i t y t o c l a s s i f y t h e i n d i f f e r e n t a n d t h o s e w h o p r o f e s s e d n o t t o b e a n n o y e d . C h a n g i n g t h e l e v e l o f s i g n i f i c a n c e t o 1 0 % a n d 2 0 % d i d n o t r e s u l t i n a n y c h a n g e i n t h e d i s c r i m i n a n t f u n c t i o n o r t h e p e r c e n t a g e c o r r e c t l y c l a s s i f i e d . T a b l e s 1 6 a n d 1 7 i l l u s t r a t e t h e a b o v e . P i s c r i m i n a n t - C l a s s i f i c a t i o n A n a l y s i s A t t h i s s t a g e i t w a s d e c i d e d t o i n c r e a s e t h e n u m b e r o f v a r i a b l e s u n d e r c o n s i d e r a t i o n . T h i s w a s d o n e i n s t a g e s f r o m 5 t o 1 1 , 1 2 , 1 5 a n d f i n a l l y 1 6 v a r i a b l e s . T h e c o m p l e t e l i s t i n t h e o r d e r o f a d d i t i o n i s s h o w n i n T a b l e 1 8 . F i v e G r o u p C a s e I n r u n n i n g t h e d i s c r i m i n a n t a n a l y s i s a g a i n u s i n g t h e i n c r e a s e d n u m b e r o f v a r i a b l e s a n d f i v e g r o u p s , t h e f i r s t t h r e e v a r i a b l e s t o e n t e r t h e d i s c r i m i n a n t f u n c t i o n a n d t h e p e r c e n t a g e o f c o r r e c t c l a s s i f i c a t i o n s w e r e a l w a y s t h e s a m e a t t h e 5 % l e v e l o f s i g n i f i c a n c e . E d u c a t i o n w a s t h e f i r s t v a r i a b l e t o e n t e r a n d , b y i t s e l f , w a s a b l e t o c o r r e c t l y c l a s s i f y 2 3 . 6 % o f t h e s u b j e c t s , t h e g r e a t e s t s u c c e s s b e i n g i n c l a s s i f y i n g t h o s e w h o e i t h e r s t r o n g l y a g r e e d o r s t r o n g l y d i s a g r e e d w i t h t h e n o i s e s t a t e m e n t ( w e r e e i t h e r v e r y a n n o y e d o r n o t a t a l l a n n o y e d ) . A l m o s t n o o n e w a s c a t e g o r i z e d t o b e o f m o d e r a t e o r " m i l d " o p i n i o n ( s e e T a b l e 1 9 ) . T h e n e x t t w o v a r i a b l e s t o e n t e r t h e d i s c r i m i n a n t f u n c t i o n w e r e t h e d i s t a n c e a n d T A B L E 1 6 C O R R E C T C L A S S I F I C A T I O N M A T R I X - T H R E E G R O U P T R I A L N u m b e r o f c a s e s c l a s s i f i e d i n t o g r o u p s -G r o u p N O T A N N I N D I F F A N O Y E D N O T A N N 4 2 4 4 0 I N D I F F 6 2 1 0 A N O Y E D 8 6 1 3 0 1 % o f c a s e s c l a s s i f i e d i n t o e a c h g r o u p -N O T A N N I N D I F F A N O Y E D T O T A L G r o u p N O T A N N 4 8 . 3 4 5 1 1 6 0 . 0 0 8 6 . 0 0 I N D I F F 2 2 . 2 2 7 7 7 8 0 . 0 0 2 7 . 0 0 A N O Y E D 3 9 . 6 3 5 9 9 1 • 4 6 2 1 7 . 0 0 C o r r e c t c l a s s i f i c a t i o n m a t r i x ; 3 g r o u p s D i s c r i m i n a t o r y v a r i a b l e s ; A G E L e v e l o f s i g n i f i c a n c e : 5 % 1 9 - 3 8 % o f t h e c a s e s w e r e c o r r e c t l y c l a s s i f i e d 7 8 T A B L E 1 7 C O R R E C T C L A S S I F I C A T I O N M A T R I X - T H R E E G R O U P T R I A L G r o u p N u m b e r o f C a s e s c l a s s i f i e d i n t o g r o u p N O T A N N I N D I F F A N O Y E D N O T A N N 2 6 3 8 2 2 I N D I F F 5 1 5 7 A N O Y E D 5 3 1 1 1 5 3 % o f c a s e s c l a s s i f i e d i n t o e a c h g r o u p -G r o u p N O T A N N I N D I F F A N O Y E D N O T A N N 3 0 2 3 4 4 . 1 9 2-5 5 8 8 6 0 0 I N D I F F 1 8 5 2 5 5 . 5 6 2 5 9 3 2 7 0 0 A N O Y E D 2 4 . 4 2 5 1 1 5 2 4 4 2 2 1 7 0 0 C o r r e c t c l a s s i f i c a t i o n m a t r i x : 3 g r o u p s D i s c r i m i n a t i n g v a r i a b l e s : A G E , O W N / R T L e v e l o f s i g n i f i c a n c e : 5 % 2 8 . 4 8 % o f t h e c a s e s w e r e c o r r e c t l y c l a s s i f i e d 7 9 T A B L E 1 8 S U M M A R Y O F D I S C R I M I N A T I N G V A R I A B L E S C O N S I D E R E D O W N / R T A G E H O W L N G T N I I N C O M E ) ) i n i t i a l 5 t e s t v a r i a b l e s ) S E X E D U C D I S T T O T V E H D 1 C 0 LS'G) n e x t g r o u p o f 6 v a r i a b l e s a d d e d t o i n c r e a s e o t o t a l n u m b e r o f v a r i a b l e s t o 1 1 J O B 1 2 t h v a r i a b l e a d d e d F L O W -T R E E S B L D G S ) ) 1 3 t h t h r o u g h t 1 5 t h v a r i a b l e s a d d e d ) C A R O W N ) . 1 6 t h a n d l a s t v a r i a b l e a d d e d 8 0 T A B L E 1 9 C O R R E C T C L A S S I F I C A T I O N M A T R I X - F I V E G R O U P S N u m b e r o f c a s e s c l a s s i f i e d i n t o g r o u p -G r o u p N O T A N Y M L D N O T I N D I F F S O M A N Y V E R Y A N N O T A N Y 2 2 0 2 0 4 M L D N O T 3 7 0 8 0 1 3 I N D I F F . 1 4 0 4 0 9 S O M A N Y 5 0 0 1 2 2 4 2 V E R Y A N 4 4 0 1 7 0 5 0 % o f c a s e s c l a s s i f i e d i n t o e a c h g r o u p -N O T A N Y M L D N O T I N D I F F S O M A N Y V E R Y A N T O T A L G r o u p N O T A N Y 7 8 5 7 0 0 7 1 4 0 0 1 4 2 9 2 8 0 0 M L D N O T 6 3 7 9 0 0 1 3 7 9 0 0 2 2 4 1 5 8 0 0 I N D I F F 5 1 8 5 0 0 1 4 8 1 0 0 3 3 3 3 2 7 0 0 S O M A N Y 4 7 1 7 0 0 1 1 3 2 1 8 9 3 9 6 2 1 0 6 0 0 V E R Y A N 3 9 6 4 0 0 1 5 3 2 0 0 4 5 0 5 1 1 1 0 0 C o r r e c t c l a s s i f i c a t i o n m a t r i x : 5 g r o u p s D i s c r i m i n a t i n g v a r i a b l e s : E D U C L e v e l o f s i g n i f i c a n c e : 5 % 2 3 . 6 4 % o f t h e c a s e s w e r e c o r r e c t l y c l a s s i f i e d 8 1 t h e t o t a l n u m b e r o f v e h i c l e s w h i c h i n c r e a s e d t h e p e r c e n t a g e o f c o r r e c t c l a s s i f i c a t i o n s t o 2 8 . 5 % a n d 3 0 . 3 % r e s p e c t i v e l y . T h i s i n c r e a s e i n o v e r a l l c l a s s i f i c a t i o n a b i l i t y c a m e a b o u t t h r o u g h i n c r e a s i n g t h e p e r c e n t a g e o f t h o s e c o r r e c t l y c l a s s i f i e d i n t h e m i d d l e g r o u p s ( t h o s e o f m i l d o r n o o p i n i o n ) a n d d e c r e a s i n g t h e c o r r e c t p e r c e n t a g e s o f t h o s e w h o w e r e d e f i n i t e l y n o t a n n o y e d . S e e T a b l e s 2 0 a n d 2 1 f o r t h e e x a c t f i g u r e s . T h r e e a d d i t i o n a l v a r i a b l e s , t h e i n d i c a t o r o f t h e p r e s e n c e o f t r e e s , t h e c a r o w n e r s h i p i n d e x a n d t h e L J Q n o i s e l e v e l a l s o e n t e r e d t h e d i s c r i m i n a n t f u n c t i o n r a i s i n g t h e o v e r a l l p e r c e n t a g e o f c o r r e c t c l a s s i f i c a t i o n s t o 3 2 . 7 % ; t h e l a r g e s t i n c r e a s e s o c c u r r e d i n t h e p e r c e n t a g e o f c o r r e c t c l a s s i f i c a t i o n s o f t h o s e w h o w e r e i n d i f f e r e n t o r v e r y a n n o y e d . A t t h e 1 0 % l e v e l o f s i g n i f i c a n c e t h e l e n g t h o f r e s i d e n c y v a r i a b l e , H O W L N G , e n t e r e d t h e d i s c r i m i n a n t f u n c t i o n a n d r a i s e d t h e c o r r e c t c l a s s i f i c a t i o n p e r c e n t a g e t o 3 3 % . A t t h e 2 0 % l e v e l o f s i g n i f i c a n c e t h e p e r c e n t a g e o f c o r r e c t c l a s s i f i c a t i o n s d e c l i n e d s i n c e H O W L N G w a s r e m o v e d a s a d i s c r i m i n a t i n g v a r i a b l e a n d r e p l a c e d b y o t h e r s . T h u s , t h e " b e s t " r e s u l t s w e r e o b t a i n e d a t t h e 1 0 % l e v e l o f s i g n i f i c a n c e w i t h s e v e n v a r i a b l e s i n t h e d i s c r i m i n a n t f u n c t i o n ( E D U C , D I S T , T O T V E H , T R E E S , C A R O W N , L , a n d H O W L N G ) . T a b l e s 2 2 a n d 2 3 i l l u s t r a t e t h e a b o v e . 8 2 T A B L E 2 0 C O R R E C T C L A S S I F I C A T I O N M A T R I X - F I V E . G R O U P S N u m b e r o f c a s e s c l a s s i f i e d i n t o g r o u p N O T A N Y M L D N O T I N D I F F S O M A N Y V E R Y A N G r o u p N O T A N Y 1 1 5 1 6 5 M L D N O T 2 3 0 8 1 5 1 2 I N D I E F 9 0 2 6 1 0 S O M A N Y 2 4 1 2 1 2 6 3 4 V E R Y A N 2 3 0 1 2 2 1 5 5 % ^ f o f o c a s ; e s c l a s s i f i e d i n t o e a c h g r o u p G r o u p N O T A N Y M L D N O T I N D I F F S O M A N Y V E R Y A N T O T A L N O T A N Y 3 9 . 2 9 1 7 . 8 6 3 . 5 7 2 1 . 4 3 1 7 . 8 6 2 8 . 0 0 M L D N O T 3 9 . 6 6 0 . 0 1 3 . 7 9 2 5 . 8 6 2 0 . 6 9 5 8 . 0 0 I N D I F F 3 3 . 3 3 0 . 0 • 7 . 4 1 2 2 . 2 2 3 7 . 0 4 2 7 . 0 0 S O M A N Y 2 2 . 6 4 0 . 9 4 1 9 . 8 1 2 4 . 5 3 3 2 . 0 8 1 0 6 . 0 0 V E R Y A N 2 0 . 7 2 0 . 0 1 0 . 8 1 1 8 . 9 2 4 9 . 5 5 1 1 1 . 0 0 C o r r e c t c l a s s i f i c a t i o n m a t r i x : 5 g r o u p s D i s c r i m i n a t i n g v a r i a b l e s : E D U C , D I S T L e v e l o f s i g n i f i c a n c e : 5 % 2 8 . 4 8 % o f t h e c a s e s w e r e c o r r e c t l y c l a s s i f i e d 8 3 T A B L E 2 1 • C O R R E C T C L A S S I F I C A T I O N M A T R I X . . - T I V E G R O U P S N u m b e r o f c a s e s c l a s s i f i e d i n t o g r o u p N O T A N Y M L D N O T I N D I F F S O M A N Y V E R Y A N G r o u p N O T A N Y 1 3 4 1 2 8 . M L D N O T 2 0 1 2 8 7 . 1 1 I N D I F F 7 6 )11 3 1 0 S O M A N Y 2 3 2 0 2 0 1 8 3 5 V E R Y A N 1 7 1 1 1 0 1 7 5 6 % o f c a s e s c l a s s i f i e d i n t o e a c h g r o u p G r o u p N O T A N Y M L D N O T I N D I F F S O M A N Y V E R Y A N T O T A L N O T A N Y 4 6 . 4 3 1 4 2 9 3 . 5 7 7 . 1 - 4 2 8 . 5 7 2 8 . 0 0 M L D N O T 3 4 . 4 8 2 0 6 9 1 3 .V9 1 2 . 0 7 1 8 . 9 7 5 8 . 0 0 I N D I F F 2 5 . 9 3 2 2 2 2 3 . 7 0 1 1 . 1 1 3 7 . 0 4 2 7 . 0 0 S O M A N Y 2 1 . 7 0 1 8 8 7 9 . 4 3 1 6 . 9 8 3 3 . 0 2 1 0 6 . 0 0 V E R Y A N 1 5 . 3 2 9 9 1 9 . 0 1 1 5 . 3 2 5 0 . 4 5 1 1 1 . 0 0 C o r r e c t c l a s s i f i c a t i o n m a t r i x : 5 g r o u p s D i s c r i m i n a t i n g v a r i a b l e s : E D U C , D I S T , T O T V E H L e v e l o f s i g n i f i c a n c e : 5 % 3 0 . 3 0 % o f t h e c a s e s w e r e c o r r e c t l y c l a s s i f i e d 8 4 T A B L E 2 2 C O R R E C T C L A S S I F I C A T I O N M A T R I X - F I V E G R O U P S N u m b e r o f c a s e s c l a s s i f i e d i n t b s g r o u p N O T A N Y M L D N O T I N D I F F S O M A N Y V E R Y A N G r o u p N O T A N Y 1 4 2 . 3 3 6 M L D N O T 1 3 1 0 1 7 7 1 1 I N D I F F 5 6 3 6 7 S O M A N Y 2 0 0 1 5 1 9 1 8 3 4 V E R Y A N 1 7 1 2 6 1 3 6 3 % o f c a s e s c l a s s i f i e d i n t o e a c h { j r o u p G r o u p N O T A N Y M L D N O T I N D I F F S O M A N Y V E R Y A N T O T A L N O T A N Y 5 0 . 0 0 7 . 1 4 1 0 ; 7 1 1 0 7 1 2 1 4 3 2 8 . 0 0 M L D N O T 2 2 . 4 1 1 7 . 2 4 2 9 . 3 1 1 2 0 7 1 8 9 7 5 8 . 0 0 I N D I F F 1 8 . 5 2 2 2 . 2 2 1 1 . 1 1 2 2 . 2 2 2 5 . 9 3 2 7 . 0 0 S O M A N Y 1 8 . 8 7 1 4 . 1 5 1 7 . 9 2 1 6 . 9 8 3 2 . 0 8 1 0 6 . 0 0 V E R Y A N 1 5 . 3 2 1 0 . 8 1 5 . 4 1 1 1 . 7 1 5 6 . 7 6 1 1 1 . 0 0 C o r r e c t c l a s s i f i c a t i o n m a t r i x : 5 g r o u p s 5 gvcup i D i s c r i m i n a t i n g v a r i a b l e s : E D U C , D I S T , T O T V E H , T R E E S , C A R O W N , L 1 0 L e v e l o f s i g n i f i c a n c e : 5 % 3 2 . 7 3 % o f t h e c a s e s w e r e c o r r e c t l y c l a s s i f i e d 8 5 T A B L E 2 3 C O R R E C T C L A S S I F I C A T I O N M A T R I X . - F I V E . G R O U P S G r o u p N u m b e r o f c a s e s N O T A N Y M L D N O T c l a s s i f i e d i n t o g r o u p I N D I F F S O M A N Y V E R Y A N N O T A N Y 1 3 5 4 2 4 M L D N O T 1 3 1 3 . 1 6 6 1 0 I N D I F F 5 3 9 4 6 S O M A N Y 1 9 1 5 2 7 1 4 3 1 V E R Y A N 2 1 1 6 8 6 6 0 % o f c a s e s c l a s s i f i e d i n t o e a c h g r o u p N O T A N Y M L D N O T I N D I F F S O M A N Y V E R Y A N T O T A L G r o u p N O T A N Y 4 6 . 4 3 1 7 . 8 6 1 4 . 2 9 7 . 1 4 1 4 2 9 2 8 0 0 M L D N O T 2 2 . 4 1 2 2 . 4 1 2 7 . 5 9 1 0 . 3 4 1 7 2 4 5 8 0 0 I N D I F F 1 8 . 5 2 1 1 . 1 1 3 3 . 3 3 1 4 . 8 1 2 2 2 2 2 7 0 0 S O M A N Y 1 7 . 9 2 1 4 . 1 5 4 2 5 . 4 7 1 3 . 2 1 2 9 2 5 1 0 6 0 0 V E R Y A N 1 8 . 9 2 1 4 . 4 1 7 . 2 1 5 . 4 1 5 4 0 5 1 1 1 0 0 C o r r e c t c l a s s i f i c a t i o n m a t r i x : 5 g r o u p s D i s c r i m i n a t i n g v a r i a b l e s : E D U C , D I S T , T O f t E H , ; T R E E S , C A R O W N , L 1 0 , H O W L I N G L e v e l o f s i g n i f i c a n c e : 1 0 % 3 3 . 0 3 % o f t h e c a s e s w e r e c o r r e c t l y c l a s s i f i e d 86 T h r e e G r o u p C a s e T h e s a m e p r o c e d u r e a s d e s c r i b e d a b o v e w a s a l s o f o l l o w e d f o r t h e t h r e e g r o u p c a s e , t h e v a r i a b l e s b e i n g i n c r e a s e d t o 1 1 , 1 2 , 1 5 a n d 1 6 i n n u m b e r . E d u c a t i o n a n d d i s t a n c e w e r e a g a i n t h e f i r s t t w o v a r i a b l e s t o e n t e r . A t t h e 5 % l e v e l o f s i g n i f i c a n c e , t h e e d u c a t i o n v a r i a b l e w a s a b l e t o c l a s s i f y c o r r e c t l y 4 7 . 6 % o f a l l c a s e s a n d e d u c a t i o n a n d d i s t a n c e t o g e t h e r 5 2 . 4 % . C a r o w n e r s h i p w a s t h e t h i r d v a r i a b l e t o e n t e r t h e d i s c r i m i n a n t f u n c t i o n , b r i n g i n g t h e c o r r e c t c l a s s i f i c a t i o n s t o 5 6 . 1 % . 4 3 % o f t h o s e n o t a n n o y e d a n d 6 5 % o f t h o s e w h o w e r e a n n o y e d w e r e c o r r e c t l y c l a s s i f i e d b u t o n l y 2 2 % o f t h o s e w h o p r o f e s s e d t o b e i n d i f f e r e n t . T h i s i s s h o w n i n T a b l e s 2 4 , 2 5 , a n d 2 6 . A g e a l s o e n t e r e d a t t h e 5 % l e v e l o f s i g n i f i c a n c e b u t i t s o v e r -a l l e f f e c t w a s t o r e d u c e t h e p e r c e n t a g e o f c o r r e c t c l a s s i f i c a t i o n s t o 4 9 % ( i n c r e a s i n g t h e p e r c e n t a g e o f i n d i f f e r e n t c o r r e c t c l a s s i f i c a t i o n s a t t h e e x p e n s e o f t h e p e r c e n t a g e o f t h o s e a n n o y e d a n d u n a n n o y e d w h o w e r e c o r r e c t l y c l a s s i f i e d ) . S e v e r a l o t h e r v a r i a b l e s a l s o e n t e r e d t h e d i s c r i m i n a n t f u n c t i o n a t t h e 2 0 % l e v e l o f s i g n i f i c a n c e b u t i n n o c a s e w a s t h e o v e r a l l p e r c e n t a g e o f c o r r e c t c l a s s i f i c a t i o n s a s h i g h a s b y j u s t u s i n g e d u c a t i o n , d i s t a n c e a n d c a r o w n e r s h i p . I t s h o u l d b e p o i n t e d o u t , h o w e v e r , t h a t a s t h e n u m b e r o f v a r i a b l e s i n t h e d i s c r i m i n a n t f u n c t i o n i n c r e a s e d , t h e p e r c e n t a g e s o f c o r r e c t c l a s s i -f i c a t i o n s i n e a c h g r o u p t e n d e d t o b e c o m e m o r e e q u a l e v e n t h o u g h t h e o v e r a l l p e r c e n t a g e c o r r e c t l y c l a s s i f i e d d e c l i n e d . A s a n e x a m p l e , T A B L E 2 4 C O R R E C T C L A S S I F I C A T I O N : M A " T R T X - • T H R E F ) G R O U P S N u m b e r o f c a s e s c l a s s i f i e d i n t o g r o u p N O T A N Y I N D I F F V E R Y A N -G r o u p N O T A N Y 5 9 1 0 1 7 I N D I F F 1 4 4 9 V E R Y A N —JJ 9 4 2 9 9 4 % o f c a s e s c l a s s i f i e d i n t o e a c h g r o u p N O T A N Y I N D I F F V E R Y A N T O T A L G r o u p N O T A N Y 6 8 6 0 1 1 6 3 1 9 . 7 7 8 6 0 0 I N D I F F 5 1 8 5 1 4 8 1 3 3 . 3 3 2 7 0 0 V E R Y A N 4 3 3 2 1 3 3 6 4 3 . 3 2 2 1 7 0 0 C o r r e c t c l a s s i f i c a t i o n m a t r i x : 3 g r o u p s D i s c r i m i n a t i n g v a r i a b l e s : E D U C L e v e l o f s i g n i f i c a n c e : 5 % 4 7 . 5 8 % o f t h e c a s e s w e r e c o r r e c t l y c l a s s i f i e d T A B L E 2 5 C O R R E C T C L A S S I F I C A T I O N M A T R I X - T H R E E G R O U P S N u m b e r o f c a s e s c l a s s i f i e d i n t o g r o u p G r o u p N O T A N Y I N D I F F V E R Y A N N O T A N Y 3 8 1 0 3 8 I N D I F F 9 2 16 V E R Y A N 4 7 3 7 1 3 3 % o f c a s e s c l a s s i f i e d i n t o e a c h g r o u p N O T A N Y I N D I F F V E R Y A N T O T A L G r o u p N O T A N Y 4 4 1 9 1 1 6 3 4 4 1 9 8 6 0 0 I N D I F F . 3 3 3 3 7 4 1 5 9 . 2 6 2 7 0 0 V E R Y A N 2 1 6 6 1 7 0 5 6 1 2 9 2 1 7 0 0 C o r r e c t c l a s s i f i c a t i o n m a t r i x : 3 g r o u p s D i s c r i m i n a t i n g v a r i a b l e s , E D U C , D I S T L e v e l o f s i g n i f i c a n c e : 5 % 5 2 . 4 2 % o f t h e c a s e s w e r e c o r r e c t l y c l a s s i f i e d T A B L E 2 6 C O R R E C T C L A S S I F I C A T I O N M A T R I X , . - T H R E E G R O U P S N u m b e r o f c a s e s c l a s s i f i e d i n t o g r o u p G r o u p N O T A N Y I N D I F F V E R Y A N N O T A N Y 3-7, 16 3 3 I N D I F F 1 3 6 1 8 V E R Y A N -5.0 2 5 1 4 2 % o f ' c a s e s c l a s s i f i e d i n t o e a c h g r o u p N O T A N Y I N D I F F V E R Y A N T O T A L G r o u p N O T A N Y 4 3 . 0 2 1 8 . 6 0 3 8 3 7 8 6 0 0 I N D I F F 4 8 . 1 5 2 2 . 2 2 2 9 6 3 2 7 0 Q V E R Y A N 2 3 . 0 4 1 1 . 5 2 6 5 4 4 2 1 7 0 0 C o r r e c t c l a s s i f i c a t i o n m a t r i x : 3 g r o u p s D i s c r i m i n a t i n g v a r i a b l e s : E D U C , D I S T , C A R O W N L e v e l o f s i g n i f i c a n c e : 5 % 5 6 . 0 6 % o f t h e c a s e s w e r e c o r r e c t l y c l a s s i f i e d 9 0 . t e n v a r i a b l e s w e r e e n t e r e d f o r t h e t h r e e g r o u p c a s e a t t h e 2 0 % l e v e l o f s i g n i f i c a n c e a n d t h e p e r c e n t a g e s o f c o r r e c t c l a s s i f i c a t i o n f o r t h o s e n o t a n n o y e d , i n d i f f e r e n t a n d a n n o y e d w e r e 4 4 % , 4 1 % a n d 5 7 % r e s p e c t i v e l y . T h e o v e r a l l p e r c e n t a g e c o r r e c t l y c l a s s i f i e d , h o w e v e r , w a s o n l y 5 2 % . T h i s l a s t c a s e i s s h o w n i n T a b l e 2 7 . T w o G r o u p C a s e T h e l a s t a t t e m p t a t c l a s s i f i c a t i o n u s i n g a l l t h e v a r i a b l e s w a s a n a t t e m p t e d t w o g r o u p c l a s s i f i c a t i o n w i t h t h o s e w h o w e r e i n d i f f e r e n t b e i n g r e m o v e d f r o m t h e s a m p l e s u b j e c t s , t h e r e d u c t i o n i n s a m p l e s i z e b e i n g l e s s t h a n 1 0 % . A g a i n e d u c a t i o n a n d d i s t a n c e w e r e t h e t w o m o s t i m p o r t a n t v a r i a b l e s , t o g e t h e r c o r r e c t l y c l a s s i f y i n g 6 5 . 7 % o v e r a l l a t t h e 5 % l e v e l o f s i g n i f i c a n c e ( 5 4 % o f t h o s e n o t a n n o y e d a n d 7 1 % o f t h o s e a n n o y e d ) . B o t h t h e O W N / R T a n d T O T V E H v a r i a b l e s a l s o e n t e r e d a t t h i s l e v e l o f s i g n i f i c a n c e b u t r e d u c e d t h e o v e r a l l a c c u r a c y t o 6 3 % . B o t h t h e u n a n n o y e d a n d a n n o y e d w e r e n o w c o r r e c t l y c l a s s i f i e d w i t h o v e r 6 0 % a c c u r a c y ( 6 0 . 5 % a n d 6 4 . 0 % r e s p e c t i v e l y ) . T h e O W N / R T v a r i a b l e d i d n o t p a s s t h e t o l e r a n c e t e s t a t t h e 1 0 % a n d 2 0 % s i g n i f i c a n c e l e v e l s b u t s e v e r a l o t h e r v a r i a b l e s w e r e a d d e d w h i c h b o o s t e d t h e o v e r a l l c o r r e c t c l a s s i f i c a t i o n t o 6 6 . 7 % f o r f i v e v a r i a b l e s ( E D U C , D I S T , T O T V E H , B L D G S , T R E E S ) a t t h e 1 0 % l e v e l o f s i g n i f i c a n c e . 6 2 - 8 % o f t h o s e w h o w e r e n o t a n n o y e d a n d 6 8 . 2 % o f t h o s e w h o w e r e h a d b e e n c o r r e c t l y c l a s s i f i e d . T a b l e s 2 8 t h r o u g h 3 1 g i v e t h e c l a s s i f i c a t i o n m a t r i c e s f o r t h e t w o g r o u p c a s e . T A B L E 2 7 C O R R E C T C L A S S I F I C A T I O N M A T R I X - T H R E E G R O U P S N u m b e r o f c a s e s c l a s s i f i e d i n t o g r o u p G r o u p N O T A N Y I N D I F F V E R Y A N N O T A N Y 3 8 2 2 2 6 I N D I F F 7 .11 9 V E R Y A N 5 1 4 3 1 2 3 % o f c a s e s c l a s s i f i e d i n t o e a c h g r o u p N O T A N Y I N D I F F V E R Y A N T O T A L G r o u p N O T A N Y 4 4 . 1 9 2 5 5 8 3 0 2 3 8 6 0 0 I N D I F F 2 5 . 9 3 4 0 7 4 3 3 3 3 2 7 0 0 V E R Y A N 2 3 . 5 0 1 9 8 2 5 6 6 8 2 1 7 0 0 C o r r e c t c l a s s i f i c a t i o n m a t r i x : 3 g r o u p s D i s c r i m i n a t i n g v a r i a b l e s : E D U C , D I S T , C A R O W N , A G E , T O T V E H , T R E E S , B L D G S , L 1 0 , L 5 0 „ T J M L e v e l o f s i g n i f i c a n c e : 2 0 % 5 2 . 1 2 % o f t h e c a s e s w e r e c o r r e c t l y c l a s s i f i e d T A B L E 2 8 C O R R E C T C L A S S I F I C A T I O N M A T R I X - T W O ' G R O U P S N u m b e r o f c a s e s c l a s s i f i e d i n t o g r o u p N O T A N Y V E R A N Y G r o u p N O T A N Y 5 9 2 7 V E R A N Y 9 4 1 2 3 % o f c a s e s c l a s s i f i e d i n t o e a c h g r o u p G r o u p N O T A N Y V E R A N Y T O T A L N O T A N Y 6 8 . 6 0 3 1 . 4 0 8 6 ; 0 0 V E R A N Y 4 3 . 3 2 5 6 . 6 8 2 1 7 . 0 0 C o r r e c t c l a s s i f i c a t i o n m a t r i x : 2 g r o u p s D i s c r i m i n a t i n g v a r i a b l e s : E D U C 2 L e v e l o f s i g n i f i c a n c e : 5 % R . 0 4 2 6 0 . 0 7 % o f t h e c a s e s w e r e c o r r e c t l y c l a s s i f i e d T A B L E 2 9 C O R R E C T C L A S S I F I C A T I O N M A T R I X - T W O G R O U P S G r o u p N u m b e r o f c a s e s c l a s s i f i e d i n t o g r o u p N O T A N Y V E R A N Y N O T A N Y 4 6 4 0 V E R A N Y 6 4 1 5 3 % o f c a s e s c l a s s i f i e d i n t o e a c h g r o u p G r o u p N O T A N Y V E R A N Y T O T A L N O T A N Y 5 3 . 4 9 4 6 . 5 1 8 6 . 0 0 V E R A N Y 2 9 . 4 9 7 0 . 5 1 2 1 7 . 0 0 C o r r e c t c l a s s i f i c a t i o n m a t r i x : 2 g r o u p s D i s c r i m i n a t i n g v a r i a b l e s : E D U C , D I S T 2 L e v e l o f s i g n i f i c a n c e : 5 % R ^ . 0 7 6 6 5 . 6 8 % o f t h e c a s e s w e r e c o r r e c t l y c l a s s i f i e d 9 4 T A B L E 3 0 C O R R E C T C L A S S I F I C A T I O N M A T R I X - T W O G R O U P S N u m b e r o f c a s e s c l a s s i f i e d i n t o g r o u p N O T A N Y V E R A N Y G r o u p N O T A N Y 5 2 3 4 V E R A N Y 7 8 1 3 9 % o f c a s e s c l a s s i f i e d i n t o e a c h g r o u p G r o u p N O T A N Y V E R A N Y T O T A L N O T A N Y 6 0 . 4 7 3 9 . 5 3 8 6 . 0 0 V E R A N Y 3 5 . 9 4 6 4 . 0 6 2 1 7 . 0 0 C o r r e c t c l a s s i f i c a t i o n m a t r i x : 2 g r o u p s D i s c r i m i n a t i n g v a r i a b l e s : E D U C , D I S T , O W N / R T , T O T V E H 2 L e v e l o f s i g n i f i c a n c e : 5 % R . 1 1 6 3 . 0 4 % o f t h e c a s e s w e r e c o r r e c t l y c l a s s i f i e d T A B L E 3 1 C O R R E C T C L A S S I F I C A T I O N M A T R I X - T W O G R O U P S N u m b e r o f c a s e s c l a s s i f i e d i n t o g r o u p N O T A N Y V E R A N Y G r o u p N O T A N Y 5 4 3 2 V E R A N Y 6 9 1 4 8 % o f c a s e s c l a s s i f i e d i n t o e a c h g r o u p N O T A N Y V E R A N Y T O T A L G r o u p N O T A N Y 6 2 7 9 3 7 2 1 8 6 0 0 V E R A N Y 3 1 8 0 6 8 2 0 2 1 7 0 0 C o r r e c t c l a s s i f i c a t i o n m a t r i x : 2 g r o u p s D i s c r i m i n a t i n g v a r i a b l e s : E D U C , D I S T , T O T V E H , B L D G S , T R E E S 2 L e v e l o f s i g n i f i c a n c e : 1 0 % R / s - . 1 2 6 6 . 6 7 % o f t h e c a s e s w e r e c o r r e c t l y c l a s s i f i e d . 9 6 F a c t o r A n a l y s i s L a s t l y , b e c a u s e o f t h e l a r g e n u m b e r o f v a r i a b l e s c o n s i d e r e d , i t w a s d e c i d e d t o a t t e m p t a f a c t o r a n a l y s i s o f t h e f i r s t f i f t e e n v a r i a b l e s i n a n e f f o r t t o o b t a i n a f e w c o m p o s i t e v a r i a b l e s o r f a c t o r s w h i c h r e f l e c t e d t h e b a s i c q u a l i t i e s o f t h e o r i g i n a l v a r i a b l e s . T w o f a c t o r a n a l y s e s w e r e p e r f o r m e d , o n e o n t h e o r i g i n a l d a t a s e t a n d a s e c o n d o n a r e v i s e d d a t a s e t o b t a i n e d b y t h e r e m o v a l , o f t h o s e s u b j e c t s w h o p r o f e s s e d i n d i f f e r e n c e t o w a r d t h e t r a f f i c n o i s e . T h e r e s u l t s o f b o t h a n a l y s e s a r e d i s c u s s e d b e l o w . O n l y s i x ( O W N / R N T , H O W L N G , B L D G S , L c n , L , N , T N I ) 5 0 1 0 o f t h e o r i g i n a l v a r i a b l e s h a d c o m m u n a l i t i e s g r e a t e r t h a n . 7 0 . I n b o t h a n a l y s e s , f i v e f a c t o r s w i t h e i g e n v a l u e s g r e a t e r t h a n 1 . 0 w e r e r e t a i n e d . 6 6 . 3 % o f t h e t o t a l v a r i a n c e o f t h e o r i g i n a l d a t a w a s e x p l a i n e d b y t h e s e f i v e f a c t o r s , a n d 6 7 . 1 % o f t h e t o t a l v a r i a n c e o f t h e r e v i s e d d a t a w a s e x p l a i n e d b y i t s f i v e f a c t o r s . T h e r o t a t e d f a c t o r m a t r i c e s a n d c o m m u n a l i t y c h e c k s f o r e a c h d a t a s e t a r e p r e s e n t e d b e l o w i n T a b l e s 3 2 a n d 3 3 . A l t h o u g h n u m b e r e d d i f f e r e n t l y , t h e f i v e f a c t o r s p r o d u c e d i n e a c h c a s e m a y b e i n t e r p r e t e d i n t e r m s o f t h e s a m e v a r i a b l e s . F a c t o r I ( b o t h d a t a s e t s ) T h i s f a c t o r , w h i c h s e r v e s a s a d i s t u r b a n c e a n d s e p a r a t i o n i n d e x , a c c o u n t s f o r 2 4 . 9 % o f t h e t o t a l v a r i a n c e i n t h e o r i g i n a l d a t a a n d 2 4 . 8 % i n t h e r e v i s e d d a t a . I t h a s h i g h l o a d i n g s , p o s i t i v e o r 9 7 T A B L E 3 2 R O T A T E D F A C T O R M A T R I X ( 3 A N D 5 G R O U P C A S E S ) V a r i a b l e F 1 F 2 F 3 F 4 F 5 O W N / R T - 0 0 8 1 7 4 0 7 9 2 4 9 - 0 0 7 4 6 6 0 2 1 0 4 1 - 0 1 7 8 2 3 H O W L N G ; - 0 0 0 3 1 5 - 0 8 2 9 9 4 . 0 0 1 4 7 9 - 0 0 9 5 1 1 - 0 1 7 7 5 1 S E X -o 0 8 1 1 9 0 0 8 2 2 5 0 7 8 9 5 0 - 0 0 6 2 9 3 - 0 1 2 9 7 0 A G E - 0 1 2 7 7 6 - 0 6 5 6 0 0 - 0 0 7 3 7 3 0 1 0 2 3 4 - 0 4 0 4 4 0 J O B . 0 0 6 1 3 1 - 0 1 0 9 0 8 0 8 1 1 9 6 0 0 0 7 6 4 6 - 0 1 0 2 4 0 E D U C . -o 0 0 9 1 1 0 2 1 5 3 8 - 0 2 5 5 1 6 0 0 5 7 3 0 0 6 7 8 4 1 I N C O M E - 0 0 5 2 5 2 - 0 0 0 2 7 3 - 0 0 5 4 1 0 0 0 1 5 8 0 0 7 2 1 2 6 F L O W - 0 0 0 9 0 8 - 0 0 4 2 1 2 - 0 0 1 1 5 8 - 0 5 2 2 1 6 -o 0 3 6 7 5 T R E E S 0 4 4 8 0 8 - 0 0 2 8 8 0 - 0 2 2 5 1 6 - 0 5 3 8 1 1 - 0 2 6 6 9 4 B L D G S -° 0 6 2 7 5 - 0 2 2 6 9 4 0 1 0 4 0 3 - 0 7 9 7 5 0 0 1 5 2 8 4 T O T V E H 0 5 2 0 3 8 0 0 1 2 9 2 5 - 0 0 3 7 7 7 - 0 6 1 2 1 0 - 0 1 3 3 2 0 L 5 0 0 9 7 4 9 9 0 0 4 7 1 6 - 0 0 0 5 1 1 - 0 0 1 4 2 0 - 0 0 0 9 7 1 L 1 0 0 9 1 5 1 1 - 0 0 6 2 8 9 - 0 0 5 4 - 3 1 - 0 0 8 8 6 4 . 0 0 4 8 5 2 D I S T 0 6 1 9 7 2 - 0 0 8 3 8 0 0 0 3 4 9 1 - 0 1 3 9 7 9 0 0 0 7 2 1 T N I 0 9 2 7 7 9 0 1 4 0 7 8 0 0 0 5 6 1 0 1 4 8 3 8 - 0 0 8 3 4 7 C h e c k <Mi< C o m m u n a l i t i e s B e f o r e A f t e r V a r i a b l e R o t a t i o n R o t a t i o n D i f f e r e n c e O W N / R T 0 7 1 6 3 4 0 7 1 6 3 4 0 0 0 0 0 1 H O W L N G ' 0 7 2 9 5 9 0 7 2 9 5 8 0 0 0 0 0 1 S E X 0 6 5 7 4 6 0 6 5 7 4 5 0 0 0 0 0 0 A G E 0 6 2 6 1 1 0 6 2 6 1 1 0 0 0 0 0 1 J O B 0 6 9 1 2 7 0 6 9 1 2 6 0 0 0 0 0 0 E D U C 0 5 7 5 1 0 0 5 7 5 1 0 0 0 0 0 0 0 I N C O M E 0 5 2 6 1 6 0 5 2 6 1 5 0 0 0 0 0 0 F L O W 0 2 7 6 0 0 0 2 7 5 9 9 0 0 0 0 0 0 T R E E S 0 6 1 3 1 3 0 6 1 3 1 3 0 0 0 0 0 1 B L D G S 0 7 2 5 6 3 0 7 2 5 6 3 0 0 0 0 0 1 T O T V E H ' 0 6 8 1 3 4 0 6 8 1 3 4 0 0 0 0 0 1 L 5 0 ' 0 9 5 3 1 5 0 9 5 3 1 5 0 0 0 0 0 1 L 1 0 0 8 5 4 2 3 0 8 5 4 2 3 0 . 0 0 0 0 1 D I S T 0 4 1 1 8 9 0 4 1 1 8 8 0 0 0 0 0 0 T N I 0 9 0 9 6 4 0 . 9 0 9 6 3 0 . 0 0 0 0 1 R o t a t e d f a c t o r m a t r i x a n d c o m m u n a l i t i e s f o r 3 a n d 5 g r o u p c a s e . 98 T A B L E 3 3 R O T A T E D F A C T O R M A T R I X ( 2 G R O U P C A S E ) V a r i a b l e F 1 F 2 F 3 F 4 F 5 O W N / R T - 0 . 0 5 6 3 2 0 0 2 2 311>9 - 0 0 6 8 0 3 - 0 7 8 1 3 7 . - 0 1 7 3 9 8 H O W L N G . - 0 . 0 2 3 3 4 - 0 1 1 0 2 6 0 0 3 8 6 9 0 8 3 2 5 1 - 0 1 4 7 2 2 S E X - 0 0 7 0 9 6 - 0 0 8 2 1 9 0 7 9 8 1 5 - 0 0 8 1 0 5 - 0 1 0 8 8 9 A G E - 0 1 1 1 6 0 0 0 8 9 5 8 - 0 0 8 1 0 2 0 6 9 9 5 0 - 0 3 5 8 8 8 J O B 0 0 3 3 1 6 0 0 8 4 9 8 0 8 0 7 8 0 0 0 1 0 9 2 9 - 0 0 9 1 5 8 E D U C 0 0 0 1 4 6 0 0 3 1 6 0 - 0 2 9 0 1 3 - 0 2 5 9 6 6 0 6 5 2 8 4 I N C O M E - 0 0 7 3 6 3 0 0 1 0 6 3 - 0 0 3 5 9 6 - 0 0 0 0 2 9 0 7 8 3 2 3 F L O W - 0 0 1 6 4 5 - 0 5 5 0 5 5 - 0 0 2 4 1 4 0 0 5 5 3 1 - 0 0 0 6 2 5 T R E E S 0 4 7 6 0 7 - 0 5 2 7 3 2 - 0 1 9 1 1 5 0 0 6 5 0 3 9 0 2 4 7 8 2 B L D G S - 0 O S 3 5 0 - 0 8 0 5 9 1 0 1 2 1 0 0 0 2 0 7 4 7 0 1 1 0 0 3 T O T V E H 0 5 3 2 2 8 - 0 6 0 3 6 3 - 0 0 3 2 8 6 - 0 . 1 2 - 7 4 7 - 0 1 4 5 8 5 L 5 0 0 9 7 7 2 6 0 0 1 4 8 0 0 0 0 9 3 8 - 0 0 4 8 0 6 0 0 1 8 3 4 E l 0 0 9 2 1 2 3 - 0 0 6 1 7 3 - 0 0 2 3 0 2 0 . 0 6 6 3 7 0 0 7 8 9 8 D I S T 0 5 9 4 6 2 - 0 1 6 3 5 0 - 0 0 1 0 3 5 0 0 2 8 8 7 - 0 . 0 6 2 3 5 T N I 0 9 3 0 0 4 0 1 7 6 4 0 0 . 0 0 4 8 3 - 0 . 1 3 7 7 9 - 0 . 0 5 8 4 0 C h e c k o n C o m m u n a l i t i e s B e f o r e A f t e r V a r i a b l e R o t a t i o n R o t a t i o n D i f f e r e n c e O W N / R T 0 7 0 2 0 6 0 . 7 0 2 0 5 0 0 0 0 0 1 H O W L N G 0 7 2 8 9 5 0 . 7 2 8 9 4 0 0 0 0 0 1 S E X 0 6 6 7 2 6 0 6 6 7 2 5 0 0 0 0 0 1 A G E 0 6 4 5 1 5 0 6 4 5 1 4 0 0 0 0 0 1 J O B 0 6 8 1 2 0 0 6 8 1 2 0 0 0 0 0 0 1 E D U C 0 5 7 8 8 1 0 5 7 8 8 0 0 0 0 0 0 1 I N C O M E 0 6 2 0 2 8 0 6 2 0 2 7 0 0 0 0 0 1 F L O W 0 3 0 7 0 6 0 3 0 7 0 5 0 0 0 0 0 0 T R E E S 0 6 0 6 9 0 0 6 0 6 8 9 0 0 0 0 0 1 B L D G S 0 7 2 2 6 0 0 7 2 2 5 9 0 0 0 0 0 1 T O T V E H 0 6 8 6 2 9 0 6 8 6 2 9 0 0 0 0 0 1 L 5 0 0 9 5 8 0 0 0 9 5 7 9 9 0 0 0 0 0 1 L 1 0 0 , 8 6 3 6 5 0 8 6 3 6 4 0 . 0 0 0 0 1 D I S T 0 . 3 8 5 1 4 0 3 8 5 1 4 0 . 0 0 0 0 0 T N I 0 9 1 8 5 2 0 9 1 8 5 1 0 . 0 0 0 0 1 R o t a t e d f a c t o r m a t r i x a n d c o m m u n a l i t i e s f o r 2 g r o u p c a s e . 99 n e g a t i v e , o n t h e v a r i a b l e s i n d i c a t e d i n T a b l e 3 4 . F a c t o r I I ( o r i g i n a l d a t a ) a n d F a c t o r I V ( r e v i s e d d a t a ) T h i s f a c t o r c o u l d b e s t b e d e s c r i b e d a s a t i m e a d a p t a b i l i t y -f a c t o r a n d i s r e f l e c t e d b y t h e h i g h l o a d i n g s o n t h e v a r i a b l e s i n T a b l e 3 5 . T h e a m o u n t o f v a r i a n c e a c c o u n t e d f o r i s 1 5 . 4 % i n t h e o r i g i n a l d a t a a n d 8 . 8 % i n t h e r e v i s e d d a t a . F a c t o r I I I ( b o t h d a t a s e t s ) T h i s f a c t o r a c c o u n t s f o r 1 0 . ' 7 % o f t h e v a r i a n c e i n t h e o r i g i n a l d a t a a n d 1 0 . 6 % i n t h e r e v i s e d d a t a . T h e h i g h l o a d i n g s o n t h e t w o v a r i a b l e s i n T a b l e 3 6 i n d i c a t e t h i s f a c t o r i s a n i n d e x o f p o s i t i o n o r s t a t u s i n l i f e . F a c t o r I V ( o r i g i n a l d a t a ) a n d F a c t o r I I ( r e v i s e d d a t a ) T h i s f a c t o r i s a n i n d e x o f t h e p h y s i c a l e n v i r o n m e n t a n d p a r t i c u l a r s c e n a r i o . T h e a m o u n t o f v a r i a n c e a c c o u n t e d f o r i s 8 . 5 % i n t h e o r i g i n a l d a t a a n d 1 6 . 2 % i n t h e r e v i s e d d a t a . H i g h l o a d i n g s a r e p r e s e n t o n t h e v a r i a b l e s l i s t e d i n T a b l e 3 7 . F a c t o r V ( b o t h d a t a s e t s ) T h i s f a c t o r i s a n i n d i c a t o r o f w e l l b e i n g a n d e x p e c t a t i o n s . I t a c c o u n t s f o r 6 . 8 % o f t h e t o t a l v a r i a n c e o f t h e o r i g i n a l v a r i a b l e s a n d 6 . 7 % o f t h a t o f t h e r e v i s e d d a t a a n d i s c h a r a c t e r i z e d b y h i g h l o a d i n g s o n t h e v a r i a b l e s i n T a b l e 3 8 . 1 0 0 T A B L E 3 4 F A C T O R L O A D I N G S 1 1 . 1 2 . 1 3 . 1 4 . 1 5 . T O T V E H L 5 0 L 1 0 D I S T T N I C©.r i:gitaiaTT,;d'atmf a ( . 5 2 0 3 8 ) ( . 9 7 4 9 9 ) ( . 9 1 5 1 1 ) ( . 6 1 9 7 2 ) ( . 9 2 7 7 9 ) O n R e v i . s e d d a t a . ( . 5 3 2 2 8 ) ( . 9 7 7 2 6 ) ( . 9 2 1 2 3 ) ( . 5 9 4 6 2 ) ( . 9 3 0 0 4 ) T h e f i g u r e s i n p a r e n t h e s e s s h o w t h e l o a d i n g s o n e a c h v a r i a b l e a n d a r e o b t a i n e d f r o m t h e r o t a t e d f a c t o r m a t r i x . T A B L E 3 5 2 . O W N / R T H O W L N G A G E F A C T O R L O A D I N G S ®%i<Elafeaat£at a • O iRSvYsfeaTdat-a ( . 7 9 2 4 9 ) ( - . 8 2 9 9 4 ) ( - . 6 5 6 0 0 ) ( - . 7 8 1 3 7 ) ( . 8 3 2 5 1 ) ( . 6 9 9 5 0 ) T A B L E 3 6 - F A C T O R L O A D I N G S O r i g i n a l d a t a R e v i s e d d a t a 3 . S E X ( . 7 8 9 5 0 ) ( . 7 9 8 1 5 ) 5 . J O B ( . 8 1 1 9 6 ) ( . 8 0 7 8 0 ) T A B L E 3 7 F A C T O R L O A D I N G S 8 . 9 . 1 0 . 1 1 . F L O W T R E E S B L D G S T O T V E H O r i g i n a l d a t a ( - . 5 2 2 1 6 ) ( - . 5 3 8 1 1 ) ( - . 7 9 7 5 0 ) ( - . 6 1 2 1 0 ) R e v i s e d . d a t a ( - . 5 5 0 5 5 ) ( 9 . 5 2 7 3 2 ) ( - 8 i 8 ' 0 5 9 _ l ) ( - . 6 0 3 6 3 ) 1 0 2 T A B L E 3 8 F A C T O R L O A D I N G S 6 . E D U C 7 . I N C O M E O r i g i n a l d a t a ( . 6 7 8 4 1 ) ( . 7 2 1 2 6 ) R e v i s e d d a t a ( . 6 5 2 8 4 ) ( . 7 8 3 2 3 ) 1 0 3 D i s c r i m i n a n t A n a l y s i s U s i n g F a c t o r S c o r e s H a v i n g e s t a b l i s h e d t h a t t h e a b o v e f i v e f a c t o r s m o d e r a t e l y e f f e c t i v e l y s p a n n e d t h e s p a c e o f t h e o r i g i n a l v a r i a b l e s , w e m a y t h e n c o m p u t e f a c t o r s c o r e s f o r e a c h s u b j e c t u s i n g t h e r e g r e s s i o n e q u a t i o n s ( o f w h i c h e a c h l o a d i n g i s a c o e f f i c i e n t ) . T h e s e f a c t o r s c o r e s a r e u s e d i n l i e u o f t h e o r i g i n a l v a r i a b l e s i n a n o t h e r a t t e m p t a t d i s c r i m i n a n t - c l a s s i f i c a t i o n a n a l y s i s . T h i s a n a l y s i s w a s r u n u s i n g t h e f i v e f a c t o r s t o a t t e m p t c l a s s i f i c a t i o n s o f s u b j e c t s i n t o f i v e , t h r e e , a n d t w o g r o u p s a s b e f o r e . I n a l l c a s e s t h e t i m e a d a p t a b i l i t y f a c t o r w a s d o m i n a n t . F o r c l a s s i f i c a t i o n i n t o f i v e g r o u p s t h e t i m e a d a p t a b i l i t y f a c t o r e n t e r e d a t t h e 5 % l e v e l o f s i g n i f i c a n c e b u t w a s a b l e t o c l a s s i f y c o r r e c t l y o n l y 1 6 . 1 % o f t h e s u b j e c t s . T h e d i s t u r b a n c e - s e p a r a t i o n f a c t o r w a s e n t e r e d a n d r a i s e d t h e p e r c e n t a g e o f c o r r e c t c l a s s i f i c a t i o n s t o Z 0 . 0 % . T h e c o m b i n a t i o n o f f a c t o r s p e r f o r m e d f a i r l y w e l l i n c l a s s i f y i n g t h o s e w h o w e r e i n d i f f e r e n t o r n o t a n n o y e d b u t e x t r e m e l y p o o r l y f o r t h e v e r y a n n o y e d . N o f u r t h e r f a c t o r s w e r e e n t e r e d a t t h e 1 0 % a n d 2 0 % l e v e l s o f s i g n i f i c a n c e . S e e T a b l e s 3 9 a n d 4 0 f o r t h e a b o v e r e s u l t s . T h e t i m e a d a p t a b i l i t y f a c t o r w a s t h e o n l y o n e e n t e r i n g t h e d i s c r i m i n a n t f u n c t i o n i n t h e t h r e e g r o u p d i s c r i m i n a t i o n a n a l y s i s . A s s e e n i n T a b l e 4 1 , h o w e v e r , t h i s f a c t o r w a s o n l y a b l e t o c l a s s i f y 2 2 . 4 % o f t h e c a s e s c o r r e c t l y a t t h e 5 % l e v e l o f s i g n i f i c a n c e . O v e r 5 0 % o f b o t h t h e u n a n n o y e d a n d i n d i f f e r e n t w e r e c o r r e c t l y c l a s s i f i e d 1 0 4 T A B L E 3 9 C O R R E C T C L A S S I F I C A T I O N . M A T R I X U S I N G F A C T O R S - 5 G R O U P S N u m b e r o f c a s e s c l a s s i f i e d i n t o g r o u p N O T A N Y M L D N O T I N D I F F S O M A N Y V E R Y A N G r o u p N O T A N Y 1 1 2 1 2 2 1 M L D N O T 3 2 7 2 5 2 1 I N D I F F 2 5 1 6 2 2 S O M A N Y 1 0 3 1 5 6 5 4 V E R Y A N 9 3 2 6 4 2 4 % o f c a s e s c l a s s i f i e d i n t o e a c h g r o u p G r o u p N O T A N Y M L D N O T I N D I F F S O M A N Y V E R Y A N T O T A L N O T A N Y 3 . 5 7 4 2 8 6 4 2 . 8 6 7 . 1 4 3 . 5 7 2 8 . 0 0 M L D N O T 5 . 1 7 4 6 5 5 4 3 . 1 0 3 . 4 5 1 . 7 2 5 8 . 0 0 I N D I F F 7 . 4 1 1 8 5 2 5 9 . 2 6 7 . 4 1 7 . 4 1 2 7 . 0 0 S O M A N Y 9 . 4 3 2 9 2 5 5 2 . 8 3 4 . 7 2 3 . 7 7 1 0 6 . 0 0 V E R Y A N 8 . 1 1 2 8 8 3 5 7 . 6 6 1 . 8 0 3 . 6 0 1 1 1 . 0 0 C o r r e c t c l a s s i f i c a t i o n m a t r i x : 5 g r o u p s D i s c r i m i n a t i n g f a c t o r s : T I M E A D A P T A B I L I T Y L e v e l o f s i g n i f i c a n c e : 5 % 1 6 . 0 6 % o f t h e c a s e s w e r e c o r r e c t l y c l a s s i f i e d 1 0 5 T A B L E 4 0 C O R R E C T C L A S S I F I C A T I O N M A T R I X U S I N G F A C T O R S " - 5 G R O U P S N u m b e r o f c a s e s c l a s s i f i e d i n t o g r o u p N O T A N Y M L D N O T I N D I F F S O M A N Y V E R Y A N G r o u p N O T A N Y 1 3 4 : 5 6 0 M L D N O T 2 0 1 6 8 1 4 0 I N D I F F 8 2 7 1 0 0 S O M A N Y 2 2 2 1 3 2 3 0 1 V E R Y A N 2 4 2 0 5 0 1 7 0 % o f c a s e s c l a s s i f i e d i n t o e a c h g r o u p N O T A N Y M L D N O T I N D I F F S O M A N Y V E R Y A N T O T A L G r o u p N O T A N Y 4 6 . 4 3 1 4 2 9 1 7 . 8 6 2 1 4 3 0 0 2 8 0 0 M L D N O T 3 4 . 4 8 2 7 5 9 1 3 . 7 9 2 4 1 4 0 0 5 8 . 0 0 I N D I F F 2 9 6 3 7 4 1 2 5 9 3 3 7 0 4 0 0 . 2 7 0 0 S O M A N Y 2 0 7 5 1 9 8 1 3 0 1 9 2 8 3 0 0 9 4 1 0 6 0 0 V E R Y A N 2 1 6 2 1 8 ? 0 2 4 5 0 5 1 5 . 3 2 0 0 1 1 1 0 0 C o r r e c t c l a s s i f i c a t i o n m a t r i x : 5 g r o u p s D i s c r i m i n a t i n g f a c t o r s : T I M E A D A P T A B I L I T Y , D I S T U R B A N C E - S E P A R A T I O N L e v e l o f s i g n i f i c a n c e : 5 % 2 0 . 0 0 % o f t h e c a s e s w e r e c o r r e c t l y c l a s s i f i e d T A B L E 4 1 C O R R E C T C L A S S I F I C A T I O N M A T R I X U S I N G F A C T O R S - 5 G R O U P S  N u m b e r o f c a s e s c l a s s i f i e d i n t o g r o u p N O T A N Y I N D I F F V E R Y A N G r o u p N O T A N Y 4 3 3 7 6 I N D I F F 7 1 6 4 V E R Y A N 8 1 1 2 1 1 5 % o f c a s e s c l a s s i f i e d i n t o e a c h g r G N O T A N Y I N D I F F V E R Y A N T O T A L G r o u p N O T A N Y 5 0 0 0 4 3 0 2 6 9 8 8 6 0 0 I N D I F F 2 5 9 3 5 9 2 6 1 4 8 1 2 7 0 0 V E R Y A N 3 7 3 3 5 5 7 6 6 9 1 2 1 7 0 0 C o r r e c t c l a s s i f i c a t i o n m a t r i x : 3 g r o u p s D i s c r i m i n a t i n g f a c t o r s : T I M E A D A P T A B I L I T Y L e v e l o f s i g n i f i c a n c e : 5 % 2 2 . 4 2 % o f t h e c a s e s w e r e c o r r e c t l y c l a s s i f i e d 1 0 7 -b u t l e s s t h a n 7 % o f t h e a n n o y e d w e r e s o c l a s s i f i e d . N o i m p r o v e m e n t w a s f o r t h c o m i n g a t t h e 1 0 % o r 2 0 % l e v e l s o f s i g n i f i c a n c e . A t t e m p t s t o u s e f a c t o r s c o r e s i n t w o g r o u p a n a l y s i s p r o v e d m o d e r a t e l y m o r e s u c c e s s f u l . T h e t i m e a d a p t a b i l i t y f a c t o r w a s t h e o n l y s i g n i f i c a n t f a c t o r a t t h e 5 % l e v e l o f s i g n i f i c a n c e a n d w a s a b l e t o c l a s s i f y 6 0 . 1 % o f a l l c a s e s c o r r e c t l y ( 5 1 . 1 % o f t h e u n a n n o y e d a n d 6 3 . 6 % o f t h e a n n o y e d ) . A t t h e 1 0 % a n d 2 0 % l e v e l s t h e d i s t u r b a n c e -s e p a r a t i o n a n d p h y s i c a l e n v i r o n m e n t f a c t o r s e n t e r e d t h e d i s c r i m i n a n t f u n c t i o n b u t l o w e r e d t h e o v e r a l l c o r r e c t c l a s s i f i c a t i o n s t o 5 8 . 4 % w i t h o u t m a r k e d l y i m p r o v i n g t h e b a l a n c e b e t w e e n t h e p e r c e n t a g e s o f a n n o y e d a n d u n a n n o y e d c o r r e c t l y c l a s s i f i e d . T h i s c a n b e s e e n i n T a b l e s 4 2 , 4 3 , a n d 4 4 . I n g e n e r a l , t h e f a c t o r s d i d n o t p r o v e a s f r u i t f u l i n c l a s s i f y i n g i n d i v i d u a l s c o r r e c t l y a s d i d t h e r a w v a r i a b l e s . T A B L E 4 2 C O R R E C T C L A S S I F I C A T I O N M A T R I X U S I N G . . F A C T O R S - ,2 G R O U P S  N u m b e r o f c a s e s c l a s s i f i e d i n t o g r o u p N O T A N Y V E R Y A N G r o u p N O T A N Y 4 4 4 2 V E R Y A N 7 9 1 3 8 % o f c a s e s c l a s s i f i e d i n t o e a c h g r o u p N O T A N Y V E R Y A N T O T A L G r o u p N O T A N Y 5 1 1 6 4 8 8 4 8 6 0 0 V E R Y A N 3 6 4 1 6 3 5 9 2 1 7 0 0 C o r r e c t c l a s s i f i c a t i o n m a t r i x : 2 g r o u p s D i s c r i m i n a t i n g f a c t o r s : T I M E A D A P T A B I L I T Y 2 L e v e l o f s i g n i f i c a n c e : 5 % R . 0 3 60. 0 7 % o f t h e c a s e s w e r e c o r r e c t l y c l a s s i f i e d 109 • T A B L E 4 3 C O R R E C T C L A S S I F I C A T I O N M A T R I X U S I N G F A C T O R S - 2 G R O U P S -N u m b e r o f c a s e s c l a s s i f i e d i n t o g r o u p N O T A N Y V E R Y A N G r o u p N O T A N Y 4 5 4 1 V E R Y A N 8 2 1 3 5 % o f c a s e s c l a s s i f i e d i n t o e a c h g r o u p N O T A N Y V E R Y A N T O T A L G r o u p N O T A N Y 5 2 3 3 4 7 6 7 8 6 0 0 V E R Y A N 3 7 7 9 6 2 2 1 2 1 7 0 0 C o r r e c t c l a s s i f i c a t i o n m a t r i x : 2 g r o u p s D i s c r i m i n a t i n g f a c t o r s : T I M E A D A P T A B I L I T Y , D I S T U R B A N C E - S E P A R A T I O N 2 L e v e l o f s i g n i f i c a n c e : 1 0 % R • " • . 0 3 8 5 9 - 4 1 % o f t h e c a s e s w e r e c o r r e c t l y c l a s s i f i e d • 1 1 0 T A B L E 4 4 C O R R E C T C L A S S I F I C A T I O N M A T R I X U S I N G F A C T O R S - 2 G R O U P S  N u m b e r o f c a s e s c l a s s i f i e d i n t o g r o u p N O T A N Y V E R Y A N G r o u p N O T A N Y 4 5 4 1 V E R Y A N 8 5 1 3 2 % o f c a s e s c l a s s i f i e d i n t o e a c h g r o u p N O T A N Y V E R Y A N T O T A L G r o u p N O T A N Y 5 2 3 3 4 7 6 7 8 6 0 0 V E R Y A N 3 9 1 7 6 0 8 3 2 1 7 0 0 C o r r e c t c l a s s i f i c a t i o n m a t r i x : 2 g r o u p s D i s c r i m i n a t i n g f a c t o r s : T I M E A D A P T A B I L I T Y , D I S T U R B A N C E - S E P A R A T I O N , L e v e l o f s i g n i f i c a n c e : 2 P B I Y S I S A L E N V I R O N M E N T 2 L e v e l o f s i g n i f i c a n c e : 2 0 % R . 0 4 3 5 8 . 4 2 % o f t h e c a s e s w e r e c o r r e c t l y c l a s s i f i e d I l l C H A P T E R V R E S U L T S R e s e a r c h F i n d i n g s T h e r e s u l t s o f t h e d i s c r i m i n a n t a n a l y s e s o f b o t h t h e o r i g i n a l v a r i a b l e s a n d c o m p o s i t e f a c t o r s a r e b o t h e n c o u r a g i n g a n d c o n f u s i n g . W h e n u s i n g t h e r a w d a t a s c o r e s , t h e e d u c a t i o n l e v e l i s c l e a r l y t h e m o r e u s e f u l s i n g l e v a r i a b l e i n d i s c r i m i n a t i n g a m o n g g r o u p s , w i t h t h e d i s t a n c e v a r i a b l e b e i n g n e x t i n i m p o r t a n c e ; b u t , i n c o m b i n a t i o n w i t h t h e e d u c a t i o n v a r i a b l e , t h e a d d i t i o n o f d i s t a n c e t o t h e d i s c r i m i n a n t f u n c t i o n o f f e r s g e n e r a l l y s l i g h t i m p r o v e m e n t i n t h e p e r c e n t a g e o f c o r r e c t c l a s s i f i c a t i o n s . O t h e r v a r i a b l e s e n t e r t h e d i s c r i m i n a n t f u n c t i o n , a l t h o u g h f r e q u e n t l y o n l y a t t h e 1 0 % a n d 2 0 % l e v e l s o f s i g n i f i c a n c e , b u t u s u a l l y d o n o t i m p r o v e t h e o v e r a l l c l a s s i f i c a t i o n c a p a b i l i t i e s . R a t h e r , t h e y o f t e n d e c r e a s e t h i s o v e r a l l c a p a b i l i t y b u t o f f e r g r e a t e r b a l a n c e i n t h e p e r c e n t a g e s o f c o r r e c t c l a s s i f i c a t i o n i n e a c h g r o u p . F a c t o r a n a l y s i s o n t h e o r i g i n a l v a r i a b l e s r e v e a l e d t h a t f i v e f a c t o r s w e r e a b l e t o e x p l a i n r o u g h l y 2 / 3 o f t h e t o t a l v a r i a n c e o f t h e o r i g i n a l f i f t e e n v a r i a b l e s . B e c a u s e o f t h e d o m i n a n c e o f t h e e d u c a t i o n l e v e l i n t h e e a r l i e r d i s c r i m i n a n t a n a l y s i s , i t m i g h t h a v e b e e n e x p e c t e d t h a t t h e w e l l b e i n g - e x p e c t a t i o n f a c t o r ( w h i c h i n c l u d e d e d u c a t i o n ) w o u l d b e t h a t f a c t o r m o s t l i k e l y t o e n t e r t h e d i s c r i m i n a n t f u n c t i o n w h e n t h e f i v e f a c t o r s w e r e u s e d a s p o s s i b l e d i s c r i m i n a t i n g 1 1 2 v a r i a b l e s . A t n o p o i n t , h o w e v e r , e v e n a t t h e 2 0 % l e v e l o f s i g n i f i c a n c e , d i d t h i s f a c t o r e n t e r t h e d i s c r i m i n a n t f u n c t i o n ; r a t h e r t h e s i n g l e m o s t i m p o r t a n t f a c t o r i n d i s c r i m i n a t i n g w a s t h e t i m e a d a p t a b i l i t y f a c t o r w h o s e v a r i a b l e s ( O W N / R N T , A G E , H O W L N G ) m o s t o f t e n d i d n o t e n t e r t h e d i s c r i m i n a n t f u n c t i o n w h e n t h e a n a l y s i s w a s p e r f o r m e d u s i n g t h e o r i g i n a l v a r i a b l e s . B a s e d o n t h e p e r c e n t a g e s o f c o r r e c t c l a s s i f i c a t i o n s o b t a i n e d u s i n g e a c h m e t h o d , i t i s a p p a r e n t t h a t o n l y i n t h e c a s e o f t w o g r o u p d i s c r i m i n a t i o n d o e s u s e o f f a c t o r s g i v e c o r r e c t c l a s s i f i c a t i o n p e r c e n t a g e s c l o s e t o t h o s e o b t a i n e d u s i n g t h e o r i g i n a l v a r i a b l e s . A b r i e f s u m m a r y o f " b e s t " r e s u l t s i s s h o w n i n T a b l e 4 5 . A l l p e r c e n t a g e s s h o w n b e l o w o c c u r a t t h e 5 % l e v e l o f s i g n i f i c a n c e . T h e s e r e s u l t s i n d i c a t e t h a t , f o r p r e d i c t i v e a c c u r a c y i n t h i s c a s e , o n e i s , i n g e n e r a l , m u c h b e t t e r o f f u s i n g t h e r a w v a r i a b l e d a t a t h a n c o m p o s i t e f a c t o r s c o r e s . B e l o w a r e t h e m e a n s a n d s t a n d a r d d e v i a t i o n s o f t h e 1 6 o r i g i n a l v a r i a b l e s f o r t h e f i v e a n d t h r e e g r o u p c a s e s . F r o m i n v e s t i g a t i o n o f t h e s e m e a n s a n d s t a n d a r d d e v i a t i o n s a n d k n o w l e d g e o f t h e c o d i n g o f t h e v a r i a b l e s , o b s e r v a t i o n s c a n b e m a d e w i t h r e s p e c t t o t h e v a r i a b l e s a n d t h e w a y i n w h i c h t h e y m i g h t c o n t r i b u t e t o w a r d c l a s s i f y i n g t h e s u b j e c t s i n t o t h e p a r t i c u l a r g r o u p s . S e e T a b l e s 4 6 a n d 4 7 . 1 1 3 T A B L E 4 5 S U M M A R Y O F " B E S T " R E S U L T S  O v e r a l l % o f c o r r e c t c l a s s i f i c a t i o n U s i n g o r i g i n a l v a r i a b l e s U s i n g f a c t o : r s 5 g r o u p c a s e 3 2 7 % 2 0 0 % 3 g r o u p c a s e 5 6 . 1 % 2 2 4 % 2 g r o u p c a s e 6 5 7 % 6 0 1 % T A B L E 4 6 M E A N S A N D S T A N D A R D . D E V I A T I O N S O F V A R I A B L E S - 5 G R O U P C A S E - M e a n s ( t h e l a s t c o l u m n c o n t a i n s t h e w e i g h t e d g r a n d m e a n s o v e r t h e g r o u p s u s e d i n t h e a n a l y s i s ) G r o u p N O T A N Y M L D N O T I N D I F F S O M A N Y V E R Y A N V a r i a b l e O W N / R T 1 . 5 7 1 4 1 . 5 8 6 2 1 . 6 6 6 7 1 . 7 4 5 3 1 . 7 4 7 7 1 . 6 9 7 0 H O W L N G 2 . 4 6 4 3 3 . 0 0 0 0 2 . 0 0 0 0 2 . 5 0 0 0 2 . 5 1 3 5 2 . 5 4 8 5 C A R O W N 1 . 2 6 6 7 1 . 2 6 3 2 1 . 3 7 5 0 1 . 2 0 4 8 1 . 1 1 1 1 1 . 2 0 2 7 S E X 1 . 5 0 0 0 1 . 5 8 6 2 2 1 . 5 1 8 5 1 . 5 7 5 5 1 . 5 3 1 5 1 . 5 5 1 5 A G E 3 . 8 2 1 4 3 . 7 5 4 4 2 . 7 0 3 7 3 . 3 6 1 9 3 . 2 9 7 3 3 . 3 9 4 3 J O B 3 . 5 4 1 7 4 . 1 1 9 0 3 . 8 6 3 6 4 . 0 5 6 2 3 . 5 5 4 3 3 . 8 3 9 0 E D U C 2 . 2 6 9 2 2 . 6 7 2 4 3 . 0 0 0 0 3 . 0 5 7 7 3 . 3 4 8 6 3 . 0 1 6 2 I N C O M E 4 . 7 8 2 6 4 . 5 5 3 2 4 . 7 1 4 3 4 . 7 7 9 1 4 . 6 6 6 7 4 . 6 9 6 6 r F E O W 1 . 7 8 5 7 1 . 8 1 0 3 1 . 6 6 6 7 1 . 6 6 9 8 1 . 6 6 6 7 1 . 7 0 3 0 T R E E S 1 . 8 5 7 1 1 . 8 4 4 8 1 . 8 8 8 9 1 . 7 6 4 2 1 . 7 3 8 7 1 . 7 8 7 9 B L D G S 1 . 6 4 2 9 1 . 6 3 7 9 1 . 5 9 2 6 1 . 4 9 0 6 1 . 5 5 8 6 1 . 5 6 0 6 T O T V E H 9 9 2 . 0 0 7 6 6 . 2 6 8 3 4 . 0 4 8 2 6 . 7 8 9 7 2 . 0 5 8 7 9 . 6 2 L 5 0 v 6 9 . 1 7 5 6 5 . 9 4 7 6 6 . 1 4 1 6 5 . 3 7 8 6 6 . 5 3 7 6 6 . 2 5 2 L 1 0 7 8 . 0 1 1 7 5 . 4 2 9 7 4 . 8 7 4 7 4 . 5 2 8 7 5 . 6 5 0 7 5 . 3 8 8 D I S T 2 0 5 . 3 6 1 6 6 . 6 4 1 6 8 . 7 0 1 3 0 . 7 1 1 0 8 . 2 9 1 3 8 . 9 2 T N I 5 9 . 5 6 1 5 6 . 4 1 4 5 7 . 4 5 2 5 6 . 4 8 0 5 7 . 2 2 3 5 7 . 0 5 9 c o n t ' d / T A B L E 4 6 ( c o n t ' d ) S t a n d a r d D e v i a t i o n s ( t h e l a s t c o l u m n c o n t a i n s t h e w e i g h t e d g r a n d s t a n d a r d d e v i a t i o n s o v e r t h e g r o u p s u s e d i n t h e a n a l y s i s ) G r o u p V a r i a b l e N O T A N Y M L D N O T I N D I F F S O M A N Y V E R Y A N O W N / R T 0 . 5 0 3 9 5 0 . 4 9 6 8 1 0 . 4 8 0 3 8 0 . 4 3 7 7 7 0 . 4 3 6 2 7 0 . 4 6 0 2 7 H O W L N G 1 . 7 3 1 7 1 1 . 8 3 5 3 1 . 3 8 6 8 1 . 5 9 3 1 1 . 6 3 9 6 1 . 6 5 9 2 C A R O W N 0 . 5 7 5 2 1 0 . 4 8 4 2 9 0 . 5 4 5 9 6 0 . 3 8 4 4 4 0 . 3 4 5 2 4 0 . 4 2 9 6 8 S E X 0 . 5 0 9 1 8 0 . 4 9 6 8 1 0 . 5 0 9 1 8 0 . 4 9 6 6 2 0 . 5 0 1 2 7 0 . 4 9 8 0 9 A G E 1 . 8 4 7 0 1 . 7 6 0 0 1 . 3 5 3 5 1 . 5 9 8 4 1 . 8 3 2 0 1 . 7 2 6 2 J O B 2 . 1 2 5 3 1 . 9 3 9 5 2 . 0 6 2 4 2 . 1 2 1 8 2 . 0 2 4 2 2 . 0 5 6 5 E D U C 1 . 2 9 2 6 1 . 3 6 8 7 1 . 5 6 8 9 1 . 3 9 9 5 1 . 5 1 5 8 2 . 4 6 8 2 I N C O M E 2 . 2 6 0 1 2 . 2 4 6 3 2 . 0 9 6 6 1 . 7 8 0 3 2 . 3 2 6 4 2 . 1 1 3 9 F L O W 0 . 4 1 7 8 6 0 . 3 9 5 4 5 0 . 4 8 0 3 8 0 . 4 7 2 5 2 0 . 4 7 3 5 4 0 . 4 5 7 6 2 T R E E S 0 . 3 5 6 3 5 0 . 3 6 5 2 3 0 . 3 2 0 2 6 0 . 4 2 6 5 5 0 . 4 4 1 3 1 0 . 4 0 9 4 3 B L D G S 0 . 4 8 7 9 5 0 . 4 8 4 8 0 0 . 5 0 0 7 1 0 . 5 0 2 2 9 0 . 4 9 8 8 1 0 . 4 9 7 0 7 T O T V E H 4 3 8 . 6 0 4 1 0 . 0 6 5 6 8 . 3 9 5 1 8 . 2 0 5 5 2 . 3 4 5 1 5 . 2 2 L 5 0 6 . 3 8 5 8 5 . 6 2 6 3 5 . 8 3 1 0 5 . 0 4 9 7 4 . 2 9 7 9 5 . 1 8 1 7 L 1 0 5 . 9 9 2 8 5 . 3 2 8 8 5 . 7 6 0 0 5 . 0 5 0 2 3 . 7 8 2 1 4 . 9 2 7 5 D I S T 2 1 6 . 8 7 1 6 0 . 7 3 1 8 6 . 2 6 1 3 1 . 5 1 1 0 9 . 4 2 1 4 6 . 7 0 T N I 6 . 6 1 2 3 5 . 8 2 3 6 5 . 8 3 3 3 5 . 1 0 5 6 4 . 6 9 0 8 5 . 3 4 4 6 T A B L E 4 7 M E A N S A N D S T A N D A R D D E V I A T I O N S O F VARIABLES - - 3 G R O U P C A S E M e a n s ( t h e l a s t c o l u m n c o n t a i n s t h e w e i g h t e d g r a n d m e a n s o v e r t h e g r o u p s u s e d i n t h e a n a l y s i s ) G r o u p N O T A N Y I N D I F F V E R Y A N V a r i a b l e O W N / R T 1 . 5 8 1 4 1 . 6 6 6 7 d j . 7 4 6 5 1 . 6 9 7 0 H O W L N G 2 . 8 2 5 6 2 . 0 0 0 0 2 . 5 0 6 9 2 . 5 4 8 5 C A R O W N 1 . 2 6 4 2 1 . 3 7 5 0 1 . 1 6 1 3 1 . 2 0 5 6 S E X 1 . 5 5 8 1 1 . 5 1 8 5 1 . 5 5 3 0 1 . 5 5 1 5 A G E 3 . 7 7 6 5 2 . 7 0 3 7 3 . 3 2 8 7 3 . 3 9 4 3 J O B 3 . 9 0 9 1 3 . 8 6 3 6 3 . 8 0 1 1 3 . 8 3 4 4 E D U C 2 . 5 4 7 6 3 . 0 0 0 0 3 . 2 0 6 6 3 . 0 1 7 9 I N C O M E 4 . 6 2 8 6 4 . 7 1 4 3 4 . 7 2 2 5 4 . 6 9 7 4 F L O W 1 . 8 0 2 3 1 . 6 6 6 7 1 . 6 6 8 2 1 . 7 0 3 0 T R E E S 1 . 8 4 8 8 1 . 8 8 8 9 1 . 7 5 1 2 1 . 7 8 7 9 B L D G S 1 . 6 3 9 5 1 . 5 9 2 6 1 . 5 2 5 3 1 . 5 6 0 6 T O T V E H 8 3 9 . 7 6 8 3 4 . 0 4 9 0 1 . 0 9 8 7 9 . 6 2 L 5 0 6 6 . 9 9 8 6 6 . 1 -41. 6 5 . 9 7 1 6 6 . 2 5 2 L 1 0 7 6 . 2 7 0 7 4 . 8 7 4 7 5 . 1 0 2 7 5 . 3 8 8 D I S T 1 7 9 . 2 4 1 6 8 . 7 0 . 1 1 9 . 2 4 1 3 8 . 9 2 T N I 5 7 . 4 3 8 5 7 . 4 5 2 5 6 . 8 6 0 5 7 . 0 5 . 9 c o u t 1 d / T A B L E 4 7 ( c o n t ' d ) S t a n d a r d D e v i a t i o n s ( t h e l a s t c o l u m n c o n t a i n s t h e w e i g h t e d g r a n d s t a n d a r d d e v i a t i o n s o v e r t h e g r o u p s u s e d i n t h e a n a l y s i s ) G r o u p V a r i a b l e N O T A N Y I N D I F F V E R Y A N O W N / R T 0 . 4 9 6 2 2 0 . 4 8 0 3 8 0 . 4 3 6 0 0 0 . 4 6 0 2 7 H O W L N G . 1 . 8 0 9 7 1 . 3 8 6 8 1 . 6 1 3 4 1 . 6 5 9 2 C A R O W N 0 . 5 1 2 2 3 0 . 5 4 5 9 6 0 . 3 6 6 2 1 0 . 4 2 8 8 8 S E X 0 . 4 9 9 5 2 0 . 5 0 9 1 8 0 . 4 9 8 3 3 0 . 4 9 8 0 9 A G E 1 . 7 7 8 1 1 . 3 5 3 5 1 . 7 1 8 2 1 . 7 2 6 3 J O B 2 . 0 0 4 3 2 . 0 6 2 4 2 . 0 8 0 4 2 . 0 5 3 7 E D U C 1 . 3 4 9 6 1 . 5 6 8 9 1 . 4 6 3 9 1 . 4 6 7 5 I N C O M E 2 . 2 3 9 6 2 . 0 9 6 6 2 . 0 7 3 5 2 . 1 1 3 7 F L O W 0 . 4 0 0 5 8 0 . 4 8 0 3 8 0 . 4 7 1 9 5 0 . 4 5 7 6 2 T R E E S 0 . 3 6 0 3 1 0 . 3 2 0 2 6 0 . 4 3 3 3 5 0 . 4 0 9 4 3 B L D G S 0 . 4 8 2 9 5 0 . 5 0 0 7 1 0 . 5 0 0 5 1 0 . 4 9 7 0 7 T O T V E H 4 3 0 . 3 4 5 6 8 . 3 9 5 3 9 . 6 3 5 1 5 . 2 2 L 5 0 6 . 0 4 1 2 5 . 8 3 1 0 4 . 7 0 5 3 5 . 1 8 1 7 L 1 0 5 . 6 5 0 7 5 . 7 6 0 0 4 . 4 7 1 9 4 . 9 2 7 5 D I S T 1 8 0 . 5 4 1 8 6 . 2 6 1 2 0 . 9 6 1 4 6 . 7 0 T N I 6 . 2 3 1 4 5 . 8 3 3 3 4 . 9 0 0 6 5 . 3 4 4 6 118 O W N / R T C o d e : 1 = o w n 2 = r e n t R e n t e r s t e n d t o b e s o m e w h a t m o r e a n n o y e d t h a n o w n e r s , a f a c t w h i c h a p p e a r s i n c o n t r a s t t o w h a t m i g h t b e e x p e c t e d . H O W L N G C o d e : h i g h e r n u m b e r s i n d i c a t e l o n g e r r e s i d e n c y a t t h e a d d r e s s S u b j e c t s w h o h a v e l i v e d t h e s h o r t e s t t i m e i n t h e i r p a r t i c u l a r l o c a t i o n a r e m o s t i n d i f f e r e n t t o w a r d t r a f f i c n o i s e . A s t h e y r e m a i n i n t h e s a m e l o c a t i o n t h e y t e n d t o b e c o m e m o r e a n n o y e d w i t h t h e n o i s e u n t i l , f i n a l l y , a f t e r t h e y h a v e b e e n t h e r e e v e n l o n g e r , t h e y a p p a r e n t l y b e c o m e a c c l i m a t e d t o t h e n o i s e . C A R O W N C o d e ; t h e n u m b e r i s t h e a v e r a g e n u m b e r o f c a r s o w n e d p e r h o u s e h o l d f o r t h e g r o u p T h e v e r y a n n o y e d a r e m a r g i n a l l y l e s s l i k e l y t o o w n a c a r t h a n o t h e r g r o u p s . S E X C o d e ; 1 = m a l e 2 = f e m a l e S e x a p p e a r s t o p l a y n o r o l e i n t h e d i s c r i m i n a t i o n . A G E C o d e : h i g h e r n u m b e r s i n d i c a t e o l d e r s u b j e c t s 119 T h e a g e v a r i a b l e f o l l o w s t h e s a m e p a t t e r n a s t h e l e n g t h o f r e s i d e n c y . T h e y o u n g e s t a r e i n d i f f e r e n t , t h e n b e c o m e a n n o y e d a s t h e y g r o w o l d e r , a n d a p p a r e n t l y b e c o m e a c c l i m a t e d a n d n o t i c e t h e n o i s e l e s s a s t h e y b e c o m e o l d e r s t i l l . J O B C o d e : t h e l o w e r t h e n u m b e r , t h e g r e a t e r t h e t e n d e n c y t o w a r d a p r o f e s s i o n a l o r m a n a g e r i a l o c c u p a t i o n N o p a t t e r n i s d i s c e r n i b l e . E D U C C o d e : h i g h e r n u m b e r s i n d i c a t e a h i g h e r l e v e l o f e d u c a t i o n T h e r e a r e s t r o n g i n d i c a t i o n s p r e s e n t t h a t t h o s e w h o h a v e a t t a i n e d a h i g h e r l e v e l o f e d u c a t i o n t e n d t o b e m o r e a n n o y e d . I N C O M E C o d e : h i g h e r n u m b e r s i n d i c a t e g r e a t e r i n c o m e s N o p a t t e r n i s d i s c e r n i b l e . F L O W C o d e ; 1 =, i n t e r r u p t e d 2 = f r e e f l o w i n g A v e r y m i l d t e n d e n c y s h o w n i s f o r a f r e e f l o w i n g t r a f f i c s i t u a t i o n t o b e m o r e l i k e l y i n t h e c a s e o f t h o s e w h o a r e r e l a t i v e l y u n a n n o y e d . T R E E S C o d e ; 1 = l a r g e t r e e s i n a r e a 2 = n o l a r g e t r e e s 1 2 0 T h e a b s e n c e o f l a r g e t r e e s i s m o r e c h a r a c t e r i s t i c o f a r e a s w h e r e r e s p o n d e n t s a r e n o t a n n o y e d . A g a i n t h i s i s c o n t r a r y t o w h a t m i g h t b e e x p e c t e d . 1 1 ) B L D G S C o d e ; 1 = l a r g e b u i l d i n g s i n a r e a 2 = n o l a r g e b u i l d i n g s N o p a t t e r n i s d i s c e r n i b l e . 1 2 ) T O T V E H C o d e ; n u m b e r s a r e t h e t o t a l n u m b e r o f v e h i c l e s p a s t t h e n o i s e m e a s u r i n g a p p a r a t u s d u r i n g t h e o n e h o u r m e a s u r e m e n t f o r t h e p a r t i c u l a r a r e a . A s t r a n g e o c c u r r e n c e i s n o t e d h e r e i n t h a t b o t h t h e v e r y a n n o y e d a n d t h o s e w h o a r e n o t a t a l l a n n o y e d a r e c h a r a c t e r i z e d b y t h e h i g h e s t n u m b e r o f v e h i c l e s i n t h e f i v e g r o u p c a s e . T h e v a r i a t i o n i n t h e n u m b e r o f v e h i c l e s i s m u c h g r e a t e r , h o w e v e r , f o r t h o s e w h o a r e v e r y a n n o y e d . F o r t h e t h r e e g r o u p c a s e , t h o s e w h o a r e a n n o y e d a r e c h a r a c t e r i z e d b y h i g h e r n u m b e r s o f v e h i c l e s . 1 3 , 1 4 , 1 6 ) L 5 Q , L 1 ( ) , T N I C o d e ; n u m b e r s a r e t h e v a l u e o f t h e n o i s e i n d e x i n d B A . T h e h i g h e r t h e n u m b e r , t h e g r e a t e r t h e o b j e c t i v e l y m e a s u r e d n o i s e . N o p a t t e r n i s d i s c e r n i b l e . T h i s i s p r i m a r i l y d u e t o LEAF 121 OMITTED IN PAGE NUMBERING. ^ 122 t h e f a c t t h a t t h e m e a s u r e d n o i s e s a t r o a d s i d e w e r e n o t m a r k e d l y d i f f e r e n t i n m o s t c a s e s , p r o b a b l y b e c a u s e n o r u s h h o u r m e a s u r e m e n t s w e r e m a d e . T h i s r o u g h e q u a l i t y o f m e a s u r e d n o i s e m a n i f e s t s i t s e l f i n t h a t n o i s e v a r i a b l e s d o n o t d i r e c t l y e n t e r t h e s e t o f d i s c r i m i n a t o r y v a r i a b l e s ; r a t h e r , t h e s e p a r a t i o n o f s o u r c e a n d r e c e i v e r b e c o m e s i m p o r t a n t i n t h a t i t r e f l e c t s t h e a t t e n u a t i o n o f n o i s e o v e r d i s t a n c e . A p p e n d i c e s A a n d B d i s c u s s f u r t h e r t h e v a r i o u s i n d i c e s a n d t h e c o l l e c t i o n o f d a t a . 1 5 ) D I S T C o d e : n u m b e r s a r e a p p r o x i m a t e d i s t a n c e s , i n f e e t , f r o m s o u r c e t o r e c e i v e r T h e r e i s a s t r o n g t e n d e n c y f o r t h e d i s t a n c e s i n v o l v e d t o b e g r e a t e r f o r t h o s e w h o a r e n o t a n n o y e d o r a r e i n d i f f e r e n t . S e v e r a l s u g g e s t i o n s c a n b e m a d e a s t o w h y t h e e d u c a t i o n l e v e l i s n o t p a r t , o f t h e c o m p o s i t e f a c t o r w h i c h p r o v e d m o s t u s e f u l i n c l a s s i f y i n g s u b j e c t s i n t o g r o u p s . F i r s t , t h e c o m m u n a l i t y o r p e r -c e n t a g e o f t o t a l v a r i a n c e o f t h e e d u c a t i o n v a r i a b l e e x p l a i n e d b y a l l g i v e n f a c t o r s i s f a i r l y T o w a t 5 8 % ; a n d , o f t h i s 5 8 % , o n l y t h e s q u a r e o f i t s f a c t o r l o a d i n g o r a b o u t 4 6 % i s e x p l a i n e d b y t h e w e l l - b e i n g / e x p e c t a t i o n f a c t o r . A l s o , t h e v a r i a b l e w i t h w h i c h e d u c a t i o n i s a s s o c i a t e d i n i t s f a c t o r i s i n c o m e w h i c h , b y i t s e l f , w a s o f n o i m p o r t a n c e i n c l a s s i f y i n g s u b j e c t s i n t o t h e c o r r e c t g r o u p s . 1 2 3 O n t h e o t h e r h a n d , t h e m o s t s u c c e s s f u l f a c t o r i n t e r m s o f c o r r e c t c l a s s i f i c a t i o n s w a s t h e t i m e a d a p t a b i l i t y f a c t o r c o m p o s e d o f O W N / R T , A G E a n d H O W L N G , t w o . o f w h o s e c o m m u n a l i t i e s w e r e g r e a t e r t h a n . 7 0 . I n a d d i t i o n , a l l t h r e e v a r i a b l e s d i s p l a y e d a d e f i n i t e d i r e c t i o n a l p a t t e r n i n t h e d e s c r i p t i o n o f g r o u p m e a n s . T h e r e w a s a p o s i t i v e i n d i c a t i o n t h a t t h e m o r e l i k e l y a s u b j e c t w a s t o b e a r e n t e r , t h e m o r e l i k e l y h e a l s o w a s t o b e a n n o y e d b y t h e t r a f f i c n o i s e . B o t h t h e a * g e a n d t h e l e n g t h o f r e s i d e n c y o f t h e s u b j e c t f o l l o w e d a v e r y s i m i l a r t i m e p a t t e r n ; a t a n e a r l y s t a g e ( a g e w i s e o r i n l e n g t h o f r e s i d e n c y ) t h e s u b j e c t a p p e a r s r e l a t i v e l y i n d i f f e r e n t t o t r a f f i c n o i s e ; a s t i m e p a s s e s t h e n o i s e b e c o m e s a n n o y i n g a n d , s t i l l l a t e r , t h e i n d i v i d u a l e i t h e r b e c o m e s a c c l i m a t e d o r c h o o s e s t o i g n o r e i t . A s t o w h y t h e r e s u l t s i n g e n e r a l a r e n o t b e t t e r , t h e r e a r e s e v e r a l p o s s i b i l i t i e s . O f p r i m a r y i m p o r t a n c e i n t h i s r e g a r d i s t h e d a t a b a s e . I n b o t h i t s c o l l e c t i o n a n d s u f f i c i e n c y t h e r e a r e w e a k n e s s e s . T h e s e w e a k n e s s e s a r e d i s c u s s e d m o r e f u l l y i n A p p e n d i x A b u t t h e m a i n p o i n t s a r e s t r e s s e d h e r e . T h e d a t a w a s i n i t i a l l y c o l l e c t e d f o r a p u r p o s e o t h e r t h a n f o r w h a t i t w a s p u t t o u s e . H a d t h e r e b e e n g r e a t e r f o r e s i g h t , a m o r e c o m p l e t e a n d a p p r o p r i a t e s e t o f d a t a w o u l d h a v e b e e n c o l l e c t e d . B o t h n o i s e a n d t r a f f i c m e a s u r e m e n t s w e r e t a k e n f o r a v e r y l i m i t e d t i m e a n d , i n s o m e c a s e s , a t i n a p p r o p r i a t e p l a c e s . T h e p u r p o s e o f t h e q u e s t i o n n a i r e a d m i n i s t e r e d t o i n t e r v i e w e e s w a s n o t s u f f i c i e n t l y 1 2 4 d i s g u i s e d , t h e r e f o r e i t i s q u i t e p o s s i b l e t h a t a c e r t a i n b i a s o n t h e p a r t o f t h e r e s p o n d e n t h a s e n t e r e d . P a r t i a l l y d u e t o b o t h t h e m a n n e r o f c o l l e c t i o n a n d t h e c o d i n g o f d a t a , b o t h c a r d i n a l a n d o r d i n a l d a t a w e r e u s e d i n t h e f a c t o r a n d d i s c r i m i n a n t a n a l y s e s . T h i s m i x t u r e o f d a t a t y p e s h a s u n d o u b t e d l y l e d t o s o m e e r r o r s i n t h e a c c u r a c y a n d , c o n s e q u e n t l y , t h e p r e d i c t i v e a b i l i t y o f t h e a n a l y s e s . I d e a l l y , a l l v a r i a b l e s w h i c h c a n b e s h o u l d b e e x p r e s s e d c a r d i n a l l y w i t h o r d i n a l s t a t u s b e i n g u s e d o n l y w h e r e n e c e s s a r y , e . g . t h e r a t i n g o f n o i s e a n n o y a n c e o r t h e d i s t i n c t i o n b e t w e e n m a l e a n d f e m a l e . I t i s a l s o h i g h l y p r o b a b l e t h a t o t h e r v a r i a b l e s , d a t a w h i c h w a s n o t c o l l e c t e d , a r e i m p o r t a n t i n d e t e r m i n i n g s u s c e p t i b i l i t y t o t r a f f i c n o i s e , e . g . t h e n u m b e r o f p e a k n o i s e o c c u r r e n c e s i n t h e t i m e p e r i o d . L a s t l y , a t t e m p t s a t p e r c e i v i n g a n d u n d e r s t a n d i n g r e l a t i o n s h i p s a m o n g v a r i a b l e s b a s e d o n a n a l y s e s o f i n d i v i d u a l s c o r e s n a t h e r t h a n o f m e a n s i n v a r i a b l y l e a d s t o p o o r e r r e s u l t s t h a n i f t h e m e a n s w e r e u s e d b e c a u s e o f t h e g r e a t e r s t a b i l i t y o f m e a n s c o r e s . C o n c l u s i o n s A t l e a s t , f o r t h e v a r i a b l e s u n d e r c o n s i d e r a t i o n i n t h i s s t u d y , r a w v a r i a b l e s c o r e s o f f e r g r e a t e r p r e d i c t i v e a c c u r a c y t h a n c o m p o s i t e f a c t o r s c o r e s i n t h e c o r r e c t c l a s s i f i c a t i o n o f i n d i v i d u a l s i n t o g r o u p s b a s e d o n t h e p e r c e i v e d a n n o y a n c e t o w a r d t r a f f i c n o i s e . 1 2 5 E d u c a t i o n i s t h e s i n g l e m o s t s i g n i f i c a n t s o c i o e c o n o m i c v a r i a b l e i n c l a s s i f i c a t i o n a n d t h e p h y s i c a l s e p a r a t i o n ( d i s t a n c e ) b e t w e e n n o i s e s o u r c e a n d r e c e i v e r a p p e a r s t o b e s e c o n d i n i m p o r t a n c e . T h e t i m e a d a p t a b i l i t y f a c t o r i s t h e m o s t i m p o r t a n t c o m p o s i t e i n d e x i n c l a s s i f i c a t i o n b u t d o e s n o t f a r e a s w e l l a s e d u c a t i o n . F i n a l l y , g r e a t e r c a r e i n t h e s e l e c t i o n a n d c o l l e c t i o n o f d a t a w o u l d s e e m t o i n s u r e a n i m p r o v e m e n t o v e r t h e m o d e r a t e l y s u c c e s s f u l r e s u l t s o f t h i s s t u d y . S u g g e s t i o n s f o r F u r t h e r R e s e a r c h " A . l a r g e n u m b e r o f d a t a h a v e i n d i c a t e d t h a t t h e r e s p o n s e o f t h e i n d i v i d u a l t o a s t i m u l u s o f a g i v e n m a g n i t u d e d e p e n d s n o t o n l y o n t h e i n t e n s i t y o f t h e s t i m u l u s , b u t a l s o o n t h e s t a t e o f t h e o r g a n i s m a s d e t e r m i n e d b y i t s p r e v i o u s h i s t o r y . I t f o l l o w s t h a t n o s c a l e w h i c h p r e d i c t s a f i x e d r e l a t i o n b e t w e e n s t i m u l u s a n d r e s p o n s e c a n b e j u s t i f i e d . " ^ D e s p i t e w h a t t h e g e n e r a l l y a c c e p t a b l e a n d a v a i l a b l e r e s u l t s m a y i n d i c a t e , a g o o d s i z e d g r o u p o f i n d i v i d u a l s w i l l c o n t i n u e t o b e a n n o y e d w h e n i t a p p e a r s t h e y s h o u l d n o t b e a n d v i c e v e r s a . A n e w a p p r o a c h t o w a r d a n a l y s i s i n t h e s e c a s e s m i g h t b e t e r m e d ' s i t u a t i o n ' o r ' i n c i d e n t ' a n a l y s i s ; i . e . , i n a d d i t i o n t o t h e c o l l e c t i o n o f t h e ' n o r m a l ' s o c i o e c o n o m i c a n d p h y s i c a l d a t a , a t t e n t i o n s h o u l d b e f o c u s e d a s c l o s e l y a s p o s s i b l e o n j u s t w h a t i s t h e a n n o y i n g f a c t o r i n e a c h 1 c a s e ; e . g . t h e s i n g l e d r i v e - b y o f a m o t o r c y c l e l a t e a t 17.6 n i g h t ( a n i s o l a t e d p e a k n o i s e ) , t h e s t e a d y d r o n e o f h e a v y t r u c k s a l o n g a m a i n r o a d ( c o n t i n u o u s l o u d n o i s e ) , o r t h e a c c e l e r a t i o n o f a b u s f r o m a s t o p ( i n t e r m i t t e n t p e a k n o i s e s a b o v e t h e a m b i e n t ) . T h e p r e s e n c e o r a b s e n c e o f v a r i o u s i n c i d e n t s , a s t h e y b e c o m e k n o w n , m a y t h e n b e u s e d i n a n a l y s i s m u c h t h e s a m e a s o t h e r v a r i a b l e s . M o r e e f f o r t a n d a t t e n t i o n s h o u l d b e f o c u s e d o n a n i n d i v i d u a l ' s e x p e c t a t i o n s w i t h r e g a r d t o n o i s e a n d w a y s t o c h a r a c t e r i z e t h e s e e x p e c t a t i o n s . O f t e n t i m e s , a m e a s u r e d n o i s e e n v i r o n m e n t w h i c h s h o u l d n o t b e o f f e n s i v e o r a n n o y i n g i s f o u n d t o b e s o b y s o m e b e c a u s e , f o r o n e r e a s o n o r a n o t h e r , t h e y e x p e c t o r v i s u a l i z e a c e r t a i n a t m o s p h e r e o f q u i e t o r p r i v a c y w h i c h i s m o s t o f t e n n o t m e t ; t h u s , t h e y o f t e n b e c o m e v e r y a n n o y e d . O n I t h e o t h e r h a n d , m a n y r e g a r d e v e n a n e x c e s s i v l y n o i s y e n v i r o n -m e n t a s a n a t u r a l o n e a n d o n e o f t h e p r i c e s p a i d f o r l i v i n g i n a m o d e r n s o c i e t y . A s a n e x a m p l e , t h e v i e w t h a t a n i n d i v i d u a l h o l d s t o w a r d t h e n e c e s s i t y o f t h e n o i s e ( o r o f i t s g e n e r a t i n g a c t i v i t y ) m a y i n f l u e n c e h i s p e r c e p t i o n o f w h e t h e r i t i s t o o l o u d o r a n n o y i n g . D e s p i t e t h e s o m e w h a t a m b i g u o u s r e s u l t s , i t i s f e l t t h a t t h e b a s i c h y p o t h e s i s a n d m e t h o d o l o g y a r e s o u n d . I f f u r t h e r i n v e s t i -g a t i o n s a r e t o b e m a d e a l o n g t h e s a m e l i n e t h e f o l l o w i n g f o u n d a t i o n s n e e d t o b e l a i d : S i t e s s h o u l d b e c h o s e n t o i n s u r e t h a t t r a f f i c n o i s e i s t h e p r i m a r y s o u r c e o f n o i s e i n t h e a r e a . T h i s c o u l d b e a c c o m p l i s h e d 1 2 7 q u i c k l y b y t e l e p h o n e s u r v e y , i f p o s s i b l e ; n o e l a b o r a t e q u e s t i o n n a i r e s h o u l d b e u s e d a t t h i s s t a g e . N o i s e d a t a t o b e g a t h e r e d s h o u l d b e g a t h e r e d a t t h e h o m e ( y a r d o r p o r c h ) o f t h e r e s p o n d e n t o v e r a p e r i o d o f t i m e , e . g . s a m p l i n g o v e r a 2 4 h o u r p e r i o d o r , i f p o s s i b l e , e v e n l o n g e r . T r a f f i c d a t a c o u l d m o s t l i k e l y b e o b t a i n e d f r o m t h e c i t y e n g i n e e r i n g d e p a r t m e n t . T h e a v e r a g e a n n u a l d a i l y t r a f f i c c a n t h u s b e o b t a i n e d a n d a d j u s t e d t o g i v e a g o o d i n d i c a t i o n o f t h e t r a f f i c s i t u a t i o n i n t h e a r e a w i t h o u t g o i n g t o t h e t r o u b l e o f c o u n t i n g c a r s o n e s e l f . A s h o r t q u e s t i o n n a i r e ( n o m o r e t h a n 1 0 q u e s t i o n s ) s h o u l d b e a d m i n i s t e r e d t o o b t a i n a t t i t u d e s t o w a r d t r a f f i c n o i s e . T h e s e m a n t i c d i f f e r e n t i a l r e s p o n s e s y s t e m a p p e a r e d t o w o r k w e l l a n d o f f e r e d n o p r o b l e m s t o t h e r e s p o n d e n t i f t h e q u e s t i o n s w e r e u n d e r s t a n d a b l e a n d p r o p e r l y w o r d e d . T h e c o l l e c t i o n o f s o c i o e c o n o m i c d a t a c o u l d f o l l o w m u c h t h e s a m e p a t t e r n a s f o r t h i s s t u d y ; t h e m a j o r d i f f e r e n c e r e c o m m e n d e d w o u l d b e t o c o l l e c t a n d m a i n t a i n c a r d i n a l d a t a a s s u c h . O t h e r d a t a , s u c h a s t h e o c c u r r e n c e o f n o i s e ' i n c i d e n t s ' c o u l d b e o b t a i n e d a s d e s i r e d . F u n d a m e n t a l l y , t h e d a t a f o r t h i s s t u d y w a s g a t h e r e d o n t h e b a s i s o f b o t h t e m p o r a l a n d f i n a n c i a l p r a c t i c a l i t y . I n r e t r o s p e c t , i t i s r e c o g n i z e d t h a t t h e r e w e r e o f t e n t e c h n i c a l l y b e t t e r w a y s t o c o l l e c t t h e d a t a b u t , a s i n m a n y r e s e a r c h e n d e a v o r s , c o m p r o m i s e s 1 2 8 w e r e m a d e t o i n s u r e t h a t t h e s e t e m p o r a l a n d f i n a n c i a l c o n s t r a i n t s w e r e m e t a n d t o f a c i l i t a t e t h e a c c u m u l a t i o n a n d a n a l y s i s o f t h e d a t a . I m p l i c a t i o n s T h e p r e l i m i n a r y i m p l i c a t i o n s o f t h e r e s u l t s a r e t h a t p l a n n e r s a n d e n g i n e e r s m u s t g o b e y o n d t h e ' h a r d ' i n d i c a t o r s s u c h a s m e a s u r e d n o i s e a n d t r a f f i c c o u n t s t o u n d e r s t a n d t h e f u l l i m p a c t o f n o i s e o n i n d i v i d u a l s o r a c o m m u n i t y . I t w i l l b e c o m e n e c e s s a r y t o i n c o r p o r a t e o t h e r c h a r a c t e r i s t i c s o f t h e p e r s o n a l a n d p h y s i c a l e n v i r o n m e n t i n t o a n y a s s e s s m e n t o f n o i s e i m p a c t . I t i s h o p e d t h i s i n v e s t i g a t i o n w i l l b e o f u s e t o f u r t h e r a n u n d e r s t a n d i n g o f t h e s e p r o c e s s e s a n d v a r i a b l e s a n d t o u p g r a d e t h e a b i l i t y o f t h e t r a f f i c e n g i n e e r t o l i m i t a n d c o n t r o l t h e n o i s e p r o b l e m s i n s i t u a t i o n s o f n e w o r i n c r e a s e d t r a f f i c . F O O T N O T E " T h e o d o r e S c h u l t z , C o m m u n i t y N o i s e R a t i n g s , A p p l i e d S c i e n c e P u b l i s h e r s L t d . , L o n d o n , 1 9 7 2 , p . 3 . T h e q u o t a t i o n a s g i v e n , w a s t a k e n f r o m S c h u l t z w h o , i n t u r n , h a d o b t a i n e d i t f r o m W . C . M i c h a e l s a n d . I . T . D o s e r , " R a t i n g S c a l e M e t h o d f o r C o m p a r a t i v e L o u d n e s s M e a s u r e m e n t s , " J o u r n a l  o f t h e A c o u s t i c S o c i e t y o f A m e r i c a , V o l . 2 7 , 1955, p p . 1 1 7 3 -1 3 0 B I B L I O G R A P H Y 1 . B o o k s B a c o n , R o b e r t A . T h e T y r a n n y o f N o i s e , S t . M a r t i n ' s P r e s s , I n c . , N e w Y o r k , 1 9 7 0 . B r a g d o n , C l i f f o r d R . N o i s e P o l l u t i o n : U n q u i e t C r i s i s , U n i v . o f P e n n s y l v a n i a P r e s s , P h i l a d e l p h i a , 1 9 7 0 . - B u c h a n a n , C o l i n ( e d i t o r ) . T r a f f i c i n T o w n s : R e p o r t s o f t h e  S t e e r i n g G r o u p a n d W o r k i n g G r o u p , H e r M a j e s t y ' s S t a t i o n e r y O f f i c e , L o n d o n , 1 9 6 3 . C h a l u p n i k , J a m e s ( e d i t o r ) . T r a n s p o r t a t i o n N o i s e s :  A S y m p o s i u m o n A c c e p t a b i l i t y C r i t e r i a , U n i v . o f W a s h -i n g t o n P r e s s , S e a t t l e , 1 9 7 0 . C r o c k e r , M a l c o l m J . ( e d i t o r ) . I n t e r - N o i s e 7 2 : P r o c e e d i n g s  o f a n I n t e r n a t i o n a l C o n f e r e n c e o n N o i s e C o n t r o l E n g i n e e r - i n g , I n s t i t u t e o f N o i s e C o n t r o l E n g i n e e r i n g , W a s h i n g t o n , D . C . , 1 9 7 2 . H o e l , P a u l G . I n t r o d u c t i o n t o M a t h e m a t i c a l S t a t i s t i c s , J o h n W i l e y a n d S o n s I n c . , N e w Y o r k , 1954. H o p e , K e i t h . M e t h o d s o f M u l t i v a r i a t e A n a l y s i s „ U n i v . o f L o n d o n P r e s s L t d . , L o n d o n , 1 9 6 8 . S c h u l t z , T h e o d o r e . C o m m u n i t y N o i s e R a t i n g s , A p p l i e d S c i e n c e P u b l i s h e r s L t d . , L o n d o n , 1 9 7 2 . S i e g e l , S i d n e y . N o n p a r a m e t r i c S t a t i s t i c s f o r t h e B e h a v i o r a l  S c i e n c e - s , M c G r a w - H i l l B o o k C o . , N e w Y o r k , 1 9 5 6 . 2 . P e r i o d i c a l s a n d U n p u b l i s h e d M a t e r i a l B j e r r i n g , J a m e s H . " U B C F A C T O : F a c t o r A n a l y s i s ; U n i v . o f B r i t i s h C o l u m b i a C o m p u t i n g C e n t e r D o c u m e n t a t i o n , 1 9 6 9 . 1 3 1 B o c k , F r e d e r i c k C . " F a c t o r s I n f l u e n c i n g M o d a l T r i p A s s i g n m e n t 1 , N a t i o n a l C o o p e r a t i v e H i g h w a y R e s e a r c h  P r o g r a m R e p o r t N o . 5 7 , H i g h w a y R e s e a r c h B o a r d , W a s h i n g t o n , D . C . , 1 9 6 8 . C o n s e r v a t i o n C o u n c i l o f O n t a r i o . " A C o n f e r e n c e o n N o i s e i n t h e E n v i r o n m e n t : C a u s e s , E f f e c t s , C o n t r o l s . " T o r o n t o , 1 9 7 1 . C r e i g h t o n , H u g h . " N o i s e i n t h e E x t e r n a l E n v i r o n m e n t " R I B A J , O c t o b e r 1 9 6 6 . D i c k e r s o n , D a v i d O . " T r a n s p o r t a t i o n N o i s e P o l l u t i o n : C o n t r o l a n d A b a t e m e n t , " N T I S N o . N 7 1 - 1 5 5 5 7 , N A S A L a n g l e y R e s e a r c h C e n t e r , L a n g l e y , V a . -F o s s , R e n e N . " V e h i c l e N o i s e S t u d y : F i n a l R e p o r t : , A p p l i e d P h y s i c s L a b , U n i v . o f W a s h i n g t o n , S e a t t l e , 1 9 7 2 . G a l l o w a y , W . J . , W . E . C l a r k , a n d . J . S . K e r r i c k . " H i g h w a y , N o i s e : M e a s u r e m e n t , S i m u l a t i o n , a n d M i x e d R e a c t i o n s " , N a t i o n a l C o o p e r a t i v e H i g h w a y  R e s e a r c h P r o g r a m R e p o r t N o . 7 8 , H i g h w a y R e s e a r c h . B o a r d , W a s h i n g t o n , D . C . , 1 9 6 9 . G a m b l e , H . B . , O . H . S a u e r l a n d e r , a n d C . J . L a n g l e y . " A d v e r s e a n d B e n e f i c i a l E f f e c t s o f H i g h w a y s o n R e s i d e n t i a l P r o p e r t y V a l u e s " , T u n p u b l i s h e d r e p o r t , P e n n s y l v a n i a S t a t e U n i v e r s i t y . G e n e r a l R a d i o C o m p a n y . " A P r i m e r o f N o i s e M e a s u r e m e n t ' , W e s t C o n c o r d , M a s s . , 1 9 6 6 . G h o s h , R . K . " U r b a n C h a r a c t e r i s t i c s a s t h e D e t e r m i n a n t s o f A i r P a s s e n g e r G e n e r a t i o n " , u n p u b l i s h e d M a s t e r ' s t h e s i s , S c h o o l o f C o m m u n i t y a n d R e g i o n a l P l a n n i n g , U n i v . o f B r i t i s h C o l u m b i a , M a y 1 9 7 3 . G o r d o n , C o l i n G . , W . J . G a l l o w a y , B . A . K u g l e r , a n d D . L . N e l s o n . " H i g h w a y N o i s e : - A D e s i g n G u i d e f o r E n g i n e e r s " , N a t i o n a l C o o p e r a t i v e H i g h w a y R e s e a r c h  P r o g r a m R e p o r t N o . 1 1 7 , H i g h w a y R e s e a r c h B o a r d , W a s h . , D . C . , 1 9 7 1 . \ ' ' 1 3 2 G r i f f i t h s , I . D . , a n d F . J . L a n g d o n . " S u b j e c t i v e R e s p o n s e t o . R o a d T r a f f i c N o i s e " , B u i l d i n g R e s e a r c h S t a t i o n  C u r r e n t P a p e r 3 7 / 6 8 , A p r i l 1 9 6 8 . H a l l , F r e d L . , a n d B r i a n L . A l l e n . " T o w a r d a C o m m u n i t y I m p a c t M e a s u r e f o r A s s e s s m e n t o f T r a n s p o r t a t i o n N o i s e " , u n p u b l i s h e d r e p o r t , D e p t . o f C i v i l E n g i n e e r -i n g , M c M a s t e r U n i v e r s i t y , H a m i l t o n , O n t a r i o . H a r m e l i n k , M . D . , " N o i s e a n d V i b r a t i o n C o n t r o l f o r T r a n s p o r t a t i o n S y s t e m s " , O n t a r i o D e p a r t m e n t o f  H i g h w a y s R e p o r t N o . R R 1 6 8 , O c t o b e r 1 9 7 0 . J o h n s t o n , G . W . , a n d R . C a r o t h e r s . " A n n o y a n c e M e a s u r e -m e n t s R e l a t e d t o U r b a n T r a f f i c N o i s e E x p o s u r e " , U n i v - e r s i t y o f T o r o n t o - Y o r k U n i v e r s i t y J o i n t P r o g r a m i n  T r a n s p o r t a t i o n R e s e a r c h R e p o r t N o . 1 3 , 1 9 7 3 . K r y t e r , K a r l D . , a n d K a r l S . P e a r s o n s . " S o m e E f f e c t s o f S p e c t r a l C o n t e n t a n d D u r a t i o n o n P e r c e i v e d N o i s e L e v e l " , J o u r n a l o f t h e A c o u s t i c S o c i e t y o f A m e r i c a , V o l . 3 5 , N o . 6 , J u n e 1 9 6 3 . L a v e n d e r , D . L . " I n t e r p r e t a t i o n o f N o i s e M e a s u r e m e n t s " , J o u r n a l o f S o u n d a n d V i b r a t i o n , V o l . 1 5 , N o . 1 , 1 9 7 1 . N a t i o n a l C o o p e r a t i v e H i g h w a y R e s e a r c h P r o g r a m . " E s t a b l i s h m e n t o f S t a n d a r d s f o r H i g h w a y N o i s e " , R e s e a r c h R e s u l t s D i g e s t N o . 2 4 , H i g h w a y R e s e a r c h B o a r d , W a s h . , D . C . , D e c e m b e r 1 9 7 0 . P r i c e , A . J . " A C o m m u n i t y N o i s e S u r v e y o f t h e G r e a t e r V a n c o u v e r R e g i o n a l D i s t r i c t " , E n g i n e e r i n g R e p o r t , B a r r o n a n d S t r a c h a n , C o n s u l t i n g A c o u s t i c a l E n g i n e e r s , V a n c o u v e r , B . C . P r o c e e d i n g s o f a n I n t e r n a t i o n a l C o n f e r e n c e o n T r a n s p o r t a t i o n a n d t h e E n v i r o n m e n t - 1 9 7 2 , 1 9 7 3 , W a s h . , D . C . R o b i n s o n , D . W . , W . C . C o p e l a n d , a n d A . J . R e n n i e . " M o t o r V e h i c l e N o i s e M e a s u r e m e n t ' , T h e E n g i n e e r , V o l . 2 1 1 , M a r c h 1 9 6 1 . S a f e e r , H . B . " C o m m u n i t y N o i s e L e v e l s - A S t a t i s t i c a l P h e n o m e n o n " , J o u r n a l o f S o u n d a n d V i b r a t i o n , V o l . 2 6 , N o . 4 , 1 9 7 3 . U n i t e d S t a t e s E n v i r o n m e n t a l P r o t e c t i o n A g e n c y . " T r a n s p o r t a t i o n N o i s e a n d N o i s e f r o m E q u i p m e n t P o w e r e d b y I n t e r n a l C o m b u s t i o n E n g i n e s " , R e p o r t N o . N T I D 3 0 0 . 1 3 . U n i t e d S t a t e s P a n e l o n N o i s e A b a t e m e n t . " T h e N o i s e A r o u n d U s " , U . S . D e p t . o f C o m m e r c e , C O M 7 1 -0 0 1 4 7 , 1 9 7 0 . U n i v e r s i t y o f B r i t i s h C o l u m b i a C o m p u t i n g C e n t e r . " S t e p w i d e D i s c r i m i n a n t A n a l y s i s : B M D 0 7 M ' , a d a p t e d b y J a s o n H a l m , 1 9 7 0 . W a c h s , M a r t i n , a n d J . L . S c h o f e r . " S y s t e m s A n a l y s t ' s V i e w o f N o i s e a n d U r b a n P l a n n i n g " , A m e r i c a n  S o c i e t y o f C i v i l E n g i n e e r i n g , J o u r n a l o f t h e U r b a n  P l a n n i n g a n d D e v e l o p m e n t D i v i s i o n , O c t o b e r 1 9 7 0 . W i l l i a m s , T . E . H . " H i g h w a y E n g i n e e r i n g a n d t h e I n f l u e n c e o f G e o m e t r i c D e s i g n C h a r a c t e r i s t i c s o n N o i s e " , J o u r n a l o f S o u n d a n d Vibration, V o l . 1 5 , N o . 1 , 1 9 7 1 . W o o d s , D o n a l d L . , a n d M u r r a y F . Y o u n g . " H i g h w a y N o i s e M e a s u r e m e n t f o r E n g i n e e r i n g D e c i s i o n s " , T e x a s T r a n s p o r t a t i o n I n s t i t u t e R e s e a r c h R e p o r t 1 6 6 S 2 , C o l l e g e S t a t i o n , T e x a s , 1 9 7 1 . Y o u n g , M u r r a y F . , a n d D o n a l d L . W o o d s . " S o u r c e s a n d M e a s u r e m e n t o f H i g h w a y N o i s e " , T e x a s  T r a n s p o r t a t i o n R e s e a r c h e r , V o l . 7 , N o . 1 , T e x a s T r a n s p o r t a t i o n I n s t i t u t e , C o l l e g e S t a t i o n , T e x a s , 1 9 7 1 . " . • 134 A P P E N D I X A : D A T A D a t a T h e c o l l e c t i o n o f t h e d a t a b a s e f o r t h e p r o b l e m i n v o l v e d t h e g a t h e r i n g o f t h r e e b a s i c d a t a t y p e s : s o c i o e c o n o m i c b a c k g r o u n d d a t a a n d a t t i t u d e s t o w a r d n o i s e , i n d i c a t i o n s D o f t h e t r a f f i c n o i s e l e v e l s , a n d t r a f f i c a n d l a n d s c a p e c h a r a c t e r i s t i c s . T h e s o c i o -e c o n o m i c d a t a a n d n o i s e a t t i t u d e s w e r e o b t a i n e d t h r o u g h t h e a d m i n i s t r a t i o n o f a q u e s t i o n n a i r e c o n d u c t e d o n a d o o r b t o d o o r b a s i s . T h i s q u e s t i o n n a i r e i s s h o w n a t t h e e n d o f t h e a p p e n d i x . A p p r o x i m a t e l y s i x t y d i f f e r e n t b l o c k s i n t h r e e s e c t i o n s o f V a n c o u v e r ( t h e W e s t E n d , K i t s i l a n o , F a i r v i e w / E a s t E n d ) w e r e s e l e c t e d , a n d a n a v e r a g e o f : s i x i n t e r v i e w s p e r b l o c k w a s c o n d u c t e d . T h e t h r e e a r e a s ( W e s t E n d , K i t s i l a n o a n d F a i r v i e w ) w e r e s e l e c t e d f o r t w o r e a s o n s . I n a p r e l i m i n a r y s u r v e y o f t h e g r e a t e r V a n c o u v e r a r e a t h e s e t h r e e a r e a s w e r e a m o n g t h o s e i n d i c a t i n g a m o d e r a t e l y s t r o n g a n n o y a n c e w i t h n o i s e . A l s c o , i t w a s i n i t i a l l y f e l t t h a t t h e t h r e e a r e a s w o u l d r e p r e s e n t , b r o a d l y s p e a k i n g , d i f f e r -e n t s o c i o e c o n o m i c c l a s s e s o f p e o p l e . T h i s l a s t p r e s u m p t i o n p r o v e d 1 3 5 i n a c c u r a t e b u t r e s p o n d e n t s i n t h e t h r e e a r e a s d i d e n c o m p a s s a w i d e r a n g e o f v a l u e s f o r t h e v a r i o u s s o c i o e c o n o m i c v a r i a b l e s . T h e a p p r o x i m a t e l y t w e n t y b l o c k l o c a t i o n s w i t h i n e a c h a r e a w e r e b a s i c a l l y c h o s e n t o i n s u r e t h a t r e s p o n d e n t s w h o l i v e d a l o n g v a r i o u s t y p e s o f s t r e e t s w e r e r e p r e s e n t e d i n t h e s a m p l e . I n e a c h s e c t i o n r e s i d e n t s w e r e i n t e r v i e w e d w h o l i v e d a l o n g m a j o r a r t e r i a l s , c o l l e c t o r r o a d s , a n d s p a r s e l y t r a v e l l e d s i d e s t r e e t s . M a p s s h o w -i n g t h e b l o c k l o c a t i o n s o f i n t e r v i e w s a r e g i v e n i n C h a p t e r 3 . R e s i d e n t s w e r e u s u a l l y q u i t e w i l l i n g t o f i l l o u t t h e q u e s t i o n -n a i r e a l t h o u g h i s o l a t e d i n c i d e n t s o f r e l u c t a n c e o r r e f u s a l w e r e e n c o u n t e r e d . A n a d d i t i o n a l q u e s t i o n a s k e d o f r e s p o n d e n t s a n d n o t o n t h e q u e s t i o n n a i r e w a s w h a t t h e n o i s i e s t s t r e e t i n t h e i r a r e a w a s . A t t e m p t s w e r e a l s o m a d e t o d e t e r m i n e t h e r e l a t i v e i m p o r t a n c e o f r e d u c i n g t r a f f i c n o i s e ( i n c o m p a r i s o n w i t h r e m e d y i n g o t h e r p r o b l e m s s u c h a s a i r p o l l u t i o n ) b u t t h e q u e s t i o n a s k e d i n t h i s r e g a r d w a s p o o r l y c h o s e n a n d t h e r e s u l t s o b t a i n e d a r e i n q u e s t i o n . N o i s e a n d t r a f f i c d a t a w e r e o b t a i n e d s i m u l t a n e o u s l y , t h e s t r e e t s f r o m w h i c h r e s p o n d e n t s i n d i c a t e d t h e n o i s e w a s w o r s t b e i n g c h o s e n f o r t h e c o l l e c t i o n o f n o i s e a n d t r a f f i c d a t a . N o i s e r e a d i n g s w e r e m a d e a t s t r e e t l e v e l o n t h e s i d e o f t h e s t r e e t ( c u r b -s i d e ) i n m i d b l o c k . R e a d i n g s w e r e t a k e n h e r e a s o p p o s e d t o a t t h e r e s p o n d e n t ' s h o m e b e c a u s e i t w a s o r i g i n a l l y i n t e n d e d t o r e l a t e t h e n o i s e g e n e r a t e d w i t h t h e c o m p o s i t i o n o f t r a f f i c a l o n g t h e s t r e e t . S o u n d i l e v e l s w e r e m o n i t o r e d b y a w i n d s h i e l d e d E l e k t r e t c o n d e n s e r 1 3 6 m i c r o p h o n e c o n n e c t e d t o a B r u e l a n d K j a e r A - w e i g h t e d s o u n d l e v e l m e t e r a n d w e r e r e c o r d e d o n a c a s s e t t e t a p e r e c o r d e r . I n t h e l a b , t h e t a p e w a s p l a y e d b a c k t h r o u g h a B r u e l a n d K j a e r M o d e l 4 4 2 0 s t a t i s t i c a l d i s t r i b u t i o n a n a l y z e r a n d M o d e l 2 6 0 6 m e a s u r i n g a m p l i f i e r . t o o b t a i n t h e L . , L e . a n d L . s o u n d l e v e l s . 10 b u yo T h e h a T h d < ^ © t p y r o f b t f e d J n o i s ' S J > l e - f e e l s : ' S s a s - o b t a ' i & e d ' v u J S . H i e t h e B r u e l a n d K j a e r M o d e l 2 3 0 5 G r a p h i c L e v e l R e c o r d e r . R e a d i n g s w e r e t a k e n f o r o n e h o u r i n e e a c h l o c a t i o n ; t h e t i m e s o f d a y d u r i n g w h i c h t h e n o i s e w a s m e a s u r e d v a r i e d f r o m l o c a t i o n t o l o c a t i o n b u t d i d o c c u r b e t w e e n t h e h o u r s o f 1 0 A M a n d 4 P M . T h u s , n o r u s h h o u r t r a f f i c n o i s e w a s r e c o r d e d . A c a l i b r a t i o n t o n e o f k n o w n d e c i b e l l e v e l ( d B A ) o f a p p r o x i m a t e l y 3 0 s e c o n d s d u r a t i o n w a s p l a c e d a t t h e b e g i n n i n g o f e a c h o n e h o u r ' s r e c o r d i n g p r i o r t o t h e m e a s u r e m e n t o f e a c h l o c a t i o n ' s t r a f f i c n o i s e . D u r i n g t h e h o u r o f m e a s u r e m e n t o f t h e t r a f f i c n o i s e t h e c o m p o s i t i o n o f t r a f f i c w a s a l s o r e c o r d e d , i . e . t h e n u m b e r o f c a r s , p i c k u p s a n d v a n s , t r u c k s , b u s e s , a n d m o t o r c y c l e s p a s s i n g t h e m e a s u r i n g a p p a r a t u s ( b o t h w a y s ) i n t h e g i v e n h o u r . I n a d d i t i o n , o t h e r t r a f f i c c h a r a c t e r i s t i c s s u c h a s s p e e d a n d f l o w a n d ' l a n d s c a p e ' f e a t u r e s s u c h a s t h e p r e s e n c e o f l a r g e b u i l d i n g s o r t r e e s w e r e n o t e d . T h e f o r m u s e d t o r e c o r d t h e t r a f f i c a n d l a n d s c a p e c h a r a c -t e r . i - s t - i f G s & i s s h o w n a t t h e e n d o f t h i s a p p e n d i x . 1 3 7 C o d i n g I n c o d i n g t h e d a t a f o r u s e i n t h e c o m p u t e r b y t h e s t a t i s t i c a l p r o g r a m s i t w a s n e c e s s a r y t o m a k e s o m e c o m p r o m i s e s w h i c h h a v e , n o d o u b t , a f f e c t e d t h e r e s u l t s o b t a i n e d . I n c o d i n g t h e n o i s e a n d t h e n u m b e r o f v e h i c l e s , f o r e x a m p l e , i t w a s q u i t e e a s y t o u s e t h e e x a c t n u m b e r c o m p u t e d o r c o m p i l e d . H o w e v e r , a s t h e q u e s t i o n n a i r e w a s d e s i g n e d s o t h a t a n s w e r s c o u l d b e p l a c e d i n t o o n e o f a f e w c a t e g o r i e s , i t w a s n e c e s s a r y t o c o d e t h i s i n f o r m a t i o n s u c h t h a t a n o r d i n a l , r a t h e r t h a n c a r d i n a l , r e p r e s e n t a t i o n o f t h e d a t a w a s o b t a i n e d . T w o e x a m p l e s o f t h e a b o v e w i l l s u f f i c e t o d e m o n s t r a t e . 1 . T h e r e s p o n s e s t o c e r t a i n s t a t e m e n t s a b o u t t h e r e s i d e n t ' s a t t i t u d e s t o w a r d t r a f f i c n o i s e w e r e t o b e i n d i c a t e d o n a s e m a n t i c d i f f e r e n t i a l L i k e r t s c a l e r a t i n g s y s t e m , i . e . f i v e p o s s i b l e r e s p o n s e s w e r e p o s s i b l e : t h e i n t e r v i e w e e c o u l d s t r o n g l y a g r e e , m i l d l y a g r e e , b e i n d i f f e r e n t t o , m i l d l y d i s a g r e e , o r s t r o n g l y d i s a g r e e w i t h t h e s t a t e m e n t . I n c o d i n g t h e s e a n s w e r s i t w a s d e c i d e d t h a t a n y a n s w e r w h i c h i n d i c a t e d t h e g r e a t e s t a n n o y a n c e w o u l d b e , c o d e d 5 , a n a n s w e r w h i c h c o n v e y e d m i l d a n n o y a n c e 4 , a n d s o o n . T h u s , t h e h i g h e r t h e n u m b e r , t h e g r e a t e r t h e i n d i c a t i o n t h a t t r a f f i c n o i s e w a s b o t h e r s o m e a n d a n n o y i n g t o t f t e p e r s o n . A v a l u e o f 3 w o u l d i n d i c a t e t h e r e s p o n d e n t t o b e s o m e w h a t i n d i f f e r e n t t o h i s n o i s e 1 3 8 environment or to feel that the noise was of borderline status, noticeable perhaps but not really annoying. A value of 1 would indicate that the respondent feels he is not at a l l annoyed by traffic noise. 2. In the coding of the socioeconomic data, certain categories or levels of educational attainment were given rather than have a specific grade level mentioned. It thus became necessary to convert these educational levels to a numeric scale. This was accomplished by assigning to the lowest educational level the value 1 (in this case a public school diploma) and a 6 to the highest level (a post-graduate degree). Intermediate levels of education took on athe integer values between 1 and 6 . Again, the higher the number, the greater the corresponding level of education. The use of two types of coding, cardinal (or exact numbers) in the case of vehicle numbers and noise measurements, and ordinal (or rank order) in the case of attitudes and some socioeconomic data presents a problem in that the statistical programs are designed primarily to use cardinal values (i.e. the actual numbers). The use of ordinal rankings in statistical analyses \such as factor and dis-criminant analysis is limited because of the lack of a constant or determinate interval scale in much of the data; e.g. a 4 on the annoyance scale does not indicate twice the annoyance of a 2, and, 139 i n l i k e m a n n e r , s o m e o n e w i t h t h e e d u c a t i o n l e v e l c o d e o f 6 i s n o t t h r e e t i m e s a s i n t e l l i g e n t a s s o m e o n e w h o s e c o d e d l e v e l i s 2 . I t w a s f e l t n e c e s s a r y t o e m p l o y t h e s e s c a l e s i n t h e a n a l y s i s , h o w e v e r , b e c a u s e t h e g r e a t m a j o r i t y o f t h e d a t a c o l l e c t e d w a s i n t h i s f o r m . H e r e , g r e a t e r f o r e s i g h t i n t h e c o n s t r u c t i o n o f t h e q u e s t i o n n a i r e w o u l d h a v e b e e n e x t r e m e l y p r u d e n t a n d h e l p f u l . I n h i n d s i g h t , i t c a n b e s e e n t h a t s e v e r a l m i s t a k e s w e r e m a d e b o t h i n t h e s e l e c t i o n a n d c o l l e c t i o n o f d a t a a n a d d i t i o n t o t h e p r o b l e m s i n v o l v e d i n t h e u s e o f t h e m i x e d c o d i n g s c h e m e s d e s c r i b e d a b o v e . O f f i r s t i m p o r t a n c e w a s t h e f a c t t h a t t h e d a t a , a s c o l l e c t e d , w a s n o t i n t e n d e d t o b e u s e d f o r t h e s t a t i s t i c a l a n a l y s e s f o r w h i c h i t e v e n t u a l l y w a s u s e d . N o i s e m e a s u r e m e n t s w e r e t a k e n a t t h e r o a d -s i d e b e c a u s e i t w a s f e l t , a f f i r s t , t h a t i t w o u l d b e b e n e f i c i a l t o a t t e m p t c o r r e l a t i o n s o f t h e t r a f f i c n o i s e g e n e r a t e d w i t h t h e t r a f f i c c o m p o s i t i o n d u r i n g t h a t t i m e . I t w a s l a t e r d e c i d e d n o t t o d o t h i s . I n a n e f f o r t t o u n d e r s t a n d ' t h e r e l a t i o n b e t w e e n m e a s u r e d n o i s e a n d a n d i n d i v i d u a l ' s s u b j e c t i v e r e s p o n s e , i t w o u l d h a v e b e e n b e t t e r t o l o c a t e t h e n o i s e m e a s u r i n g a p p a r a t u s o n t h e p o r c h o r l a w n o f t h e p e r s o n s b e i n g i n t e r v i e w e d f o r t h i s w o u l d h a v e g i v e n a m u c h b e t t e r i n d i c a t i o n o f t h e n o i s e l e v e l s a c t u a l l y e x p e r i e n c e d b y t h e r e s p o n d e n t . T h e f a c t t h a t t h e r e w a s o f t e n a b l o c k o r h a l f b l o c k s e p a r a t i n g t h e r e s p o n d e n t S f r o m t h e m a j o r n o i s y s t r e e t ( w h e r e t h e n o i s e m e a s u r e -m e n t w a s m a d e ) w o u l d s e r v e t o d i m i n i s h s u b s t a n t i a l l y t h e e f f e c t s o f t h e n o i s e a t t h e h o m e o f t h e s u b j e c t . T h i s w a s p a r t i a l l y 1 4 0 a c c o u n t e d f o r b y i n c l u d i n g t h i s s e p a r a t i o n i n t h e a n a l y s i s a s o n e o f t h e v a r i a b l e s . T h e t i m e a s p e c t o f t h e d a t a c o l l e c t i o n a l s o c o u l d h a v e b e e n i m p r o v e d c o n s i d e r a b l y , p a r t i c u l a r l y w i t h r e s p e c t t o t h e c o l l e c t i o n o f n o i s e a n d t r a f f i c d a t a . B e c a u s e o f t i m e a n d s e c u r i t y c o n s t r a i n t s i n v o l v i n g u s e o f t h e n o i s e m e a s u i n g e q u i p m e n t t h e n o i s e s a m p l e s f o r a n a r e a c o n s i s t e d o f a o n e h o u r s a m p l e t a k e n d u r i n g m i d - d a y , t h u s , f o r e x a m p l e , t h e n o i s e s a m p l e f o r a p a r t i c u l a r a r e a m a y c o n s i s t o f t h e t r a f f i c n o i s e f r o m t h e p a r t i c u l a r s t r e e t f r o m 1 1 A M t o 1 2 n o o n o n a T h u r s d a y - ' ( a l l m e a s u r e m e n t s w e r e m a d e o n w e e k d a y s b e t w e e n 1 0 A M a n d 4 P M d u r i n g t h e m o n t h o f A u g u s t ) . N o i s e d a t a c o l l e c t e d i n t h i s w a y i s v a s t l y i n f e r i o r t o d a t a w h i c h i s c o l l e c t e d p r o p e r l y ; e . g . s a m p l i n g f o r a f e w s e c o n d s e v e r y f e w m i n u t e s o v e r . a 2 4 h o u r p e r i o d . E v e n t h e a b o v e , h o w e v e r , g i v e s a n o i s e p r o f i l e o n l y a t a p a r t i c u l a r p o i n t i n t i m e a n d g i v e s n o i n d i c a t i o n o f w h a t t h e l o n g e r t e r m n o i s e e n v i r o n m e n t i n t h e a r e a m a k e b e l i k e . A n o t h e r a d v e r s e a s p e c t o f t h e d a t a w a s p e r h a p s t h a t o f a g g r e g a t i o n . A t o t a l o f 3 3 1 i n t e r v i e w s w a s c o n d u c t e d i n a r e a s o f t h e c i t y q u i t e d i f f e r e n t b o t h i n t e r m s o f t h e c h a r a c t e r i s t i c s o f t h e i n t e r v i e w e e s a n d i n t h e n a t u r e o f t h e t r a f f i c i n t h e a r e a . T h e a n a l y s i s o f t h e e n t i r e b l o c k o f d a t a a s i f i t w e r e h o m o g e n e o u s m a y h a v e r e d u c e d t h e p o s s i b i l i t i e s o f o b t a i n i n g m o r e d e f i n i t i v e r e s u l t s . I m p r o v e d r e l i a b i l i t y m i g h t b e e x p e c t e d i f t h e d a t a w a s f o r m e d i n t o s m a l l e r a n d p o s s i b l y m o r e h o m o g e n e o u s d a t a b l o c k s a n d t h e 141 a n a l y s i s p e r f o r m e d o n t h e s e s m a l l e r g r o u p s . T h e o n e d r a w b a c k w i t h t h e a b o v e s u g g e s t i o n , h o w e v e r , i s t h a t a d i s a g g r e g a t i o n i n t o s m a l l e r d a t a b l o c k s i m p l i e s t h a t t h e d i s a g g r e g a t i o n b e p e r f o r m e d o n t h e b a s i s o f s o m e c o m m o n c h a r a c t e r i s t i c o f t h e d a t a b l o c k a n d t h i s w o u l d , i n e f f e c t , p r e j u d i c e o r p r e s u m e a n a n s w e r t o a n y d i s c r i m i n a n t a n a l y s i s o n t h e r e o r g a n i z e d d a t a . I n a d m i n i s t r a t i o n o f t h e i n t e r v i e w i t w a s i n i t i a l l y d e s i r e d t h a t t h e i n t e r v i e w e e n o t k n o w t h e f o c u s o f t h e i n t e r v i e w . I n m o s t c a s e s , h o w e v e r , t h e f a c t t h a t t h e i n t e r v i e w c o n c e r n e d a t t i t u d e s t o w a r d t r a f f i c n o i s e b e c a m e a p p a r e n t q u i t e q u i c k l y . I n m a n y c a s e s t h e r e s p o n d e n t s e v e n a s k e d i f t h e s u r v e y w a s s p o n s o r e d b y t h e c i t y o r p r o v i n c i a l g o v e r n m e n t i n a n e f f o r t t o c u r b w h a t t r a f f i c n o i s e a l r e a d y e x i s t e d . T h i s a t t i t u d e o n t h e p a r t o f q u i t e a f e w r e s p o n d e n t s m a y h a v e l e d t h e m t o o f f e r s h a d e d r e s p o n s e s t h e y t h o u g h t w o u l d b e h e l p f u l e i t h e r t o t h e i n t e r v i e w e r o r t o t h e i r o w n d e s i r e s , r a t h e r t h a n r e s p o n s e s w h i c h w e r e o b j e c t i v e a n d m o r e t r u t h f u l . U n f o r t u n -a t e l y , i t a p p e a r s t h a t t h e o n l y w a y t o e l i m i n a t e a p r o b l e m s u c h a s t h i s i s t h r o u g h m e t i c u l o u s d e s i g n , t e s t i n g , a n d r e d e s i g n o f t h e q u e s t i o n n a i r e . D e s p i t e t h e a b o v e l i m i t a t i o n s a n d s h o r t c o m i n i n g s , i t ^ s h o u l d b e e m p h a s i z e d t h a t , i n m a n y c a s e s , t h e d e c i s i o n s t a k e n w e r e m a d e o n g r o u n d s o f p r a c t i c a l i t y e v e n t h o u g h i t c o u l d b e s e e n t h a t t h e y w o u l d b e t e c h n i c a l l y i n f e r i o r t o ' o p t i m a l ' d e c i s i o n s m a d e u n d e r m o r e : l d e a l c o n d i t i o n s . 1 4 2 UNIVERSITY OF BRITISH COLUMBIA DEPARTMENT OF CIVIL ENGINEERING Interview No. I I I I Date r r n The Department of C i v i l Engineering of the University of B r i t i s h Columbia Is conducting th i s survey to determine how you feel about t h i s neighbourhood and improvements you would l i k e to see made. We would appreciate i t i f you could take a few moments to answer the following questions. A. F i r s t l y we would l i k e to know something about where you l i v e . 1. House Address? 2. Do you own or rent? own Q rent Q 3. How long have you l i v e d at your present address? less than 1 year Q 5 - 1 0 years • 1 - 2 years • 1 0 - 1 5 years • 3 - 5 years • > 15 years Q 4. Where did you l i v e before moving to your present address? Rural • Small town of less than 10,000 • Medium town of 10,000 - 250,000 • Large c i t y of greater than 250,000 Q 5. Number of vehicles owned by the family? cars Q trucks {~| motorcycles L ] 1 4 3 B. Now we would like to know what improvements to the neighbourhood you would like to see carried out. Governments spend about one hundred dollars per family each year on the improvement of public faci l i t ies in the Vancouver metropolitan area. Suppose you had the opportunity of deciding how "your" hundred dollars should be spent. How would you allocate your $100 among the following possible types of investments in such a way as to improve the area as you think i t should be Improved? You may spend the whole amount on any one type of improvement, or spl i t 1t among some or all of the alternatives in any amounts you wish. 1. Reduce air pollution $, 2. Improve police and fire protection $ 3. Reduce traffic noise $ 4. Reduce industrial noise $. 5. Improve parks and recreation faci l i t ies $„ 6. Improve educational faci l i t ies $ 7. Improve public transportation faci l i t ies $. 8. Improve welfare services $ 9. Improve public health and hospital faci l i t ies $ 10. Improve street and freeway faci l i t ies $ 11. Other (specify) $ TOTAL $100 1 4 4 C. We are now going to ask you some questions about the noisiness of your neighbourhood. Please answer each question as accurately as you can. In thinking about this block where you l i v e , would you please Indicate to what extent you are annoyed by each o f the following noises. 1 2 3 4 5 Not Noticeable Mildly Moderately Very noticeable but not annoying annoying annoying annoying 1. Noise from cars • • • • • 2. Noise from trucks • • • • • 3. Noise from motorcycles • • • • 4. Noise from ai rcraf t • • • • • 5. Noise from industry • d • • • 6. Noise from other houses • • • • • 7. Noise from children • • • d • 8. Noise from lawn mowers • • • • • 9. Other (specify) • • • • • Would you please indicate your agreement or disagreement with the fo l i c statements. 1. The noise from t ra f f i c in this neighbourhood i's annoying. Strongly Mildly Agree Agree Neither Agree Nor Disagree Mildly Disagree Strongly Disagree • d • • • 2. Living here with the t ra f f i c noise is a strain on my nerves. Strongly Mildly Agree Agree Neither Agree Nor Disagree Mildly Disagree Strongly Disagree • • • • • 1 4 5 3. We would seriously consider moving i f the traffic noise gets much worse. Strongly Mildly Neither Mildly Strongly Agree Agree Agree Nor Disagree Disagree Disagree • • • • d 4. Traffic noise bothers us less now than when we f i rst moved here. Strongly Mildly Neither Mildly Strongly Agree Agree Agree Nor Disagree Disagree Disagree • • • • D 5. There has been a noticeable increase In traffic noise here over the past few years. Strongly Mildly Neither Mildly Strongly Agree Agree Agree No Disagree Disagree Disagree • • • d d 6. We would (do) tolerate sorce traffic noise because we like living close to ' work/shoppi ng/schools. Strongly Mildly Neither Mildly Strongly Agree Agree Agree Nor Disagree Disagree Disagree • d • • d 7. This neighbourhood is no noisier from traffic than the last one I lived in. Strongly Mildly Neither Mildly Strongly Agree Agree Agree Nor Disagree Disagree Disagree • • a a d 8. As long as the traffic noise is continuous i t doesn't bother me; i t Is the loud bangs, rumblings and screeching which annoy me. Strongly Mildly Neither Mildly Strongly Agree Agree Agree Nor Disagree Disagree Disagree • • • d • 1 4 6 9. A few loud noises do not bother me, but so many motorcycles and/or trucks go past here that it is annoying. Strongly Agree • Mildly Agree • Neither Agree Nor Disagree • Mildly Disagree • 10. I find it much noisier from traffic downtown than here. Strongly Agree • Mildly Agree • Neither Agree Nor Disagree • Mildly Disagree • Strongly Disagree • Strongly Disagree 11. I notice the noise much less at night than during the day Strongly Agree • Mildly Agree • Neither Agree Nor Disagree • Mildly Disagree • • Strongly Disagree • 12. Traffic noise is more annoying here in the summer than in the winter. Strongly Agree Mildly Agree • Neither Agree Nor Disagree • Mildly Disagree d 13. It is only the rush hour traffic which is annoying. Strongly Agree • Mildly Agree • Neither Agree Nor Disagree • Mildly Disagree • Strongly Disagree • Strongly Disagree 14. Reducing traffic here would get rid of most of the noise. Strongly Agree • Mildly Agree • Neither Agree Nor Disagree • Mildly Disagree • • Strongly Disagree • 15. A general restriction on commuter traffic in residential areas (such as was recently done in the West End) should be encouraged to reduce traffic noise. Strongly Agree • Mildly Agree • Nei ther Agree Nor Disagree • Mildly Disagree • Strongly Disagree • 1 4 7 Now we would like to get the following factual information. What sex are you? male []] female Q Which age category dc you fall into? under 20 • 5 0 - 5 9 • 2 0 - 2 9 • 6 0 - 6 9 • 30 -39 • 70 or older • 40 - 49 • Which occupation category most closely f i ts what you do? (Note: you may f i t into more than one category). Professional • Homemaker • Managerial • Not Employed • Secretarial • Part-time Employee • Sales, Clerical • Student • Craftsman • Shift Work? • Unskilled • day Q evening • night Q What is the category of school you last attended? Public School Diploma Q High School Diploma • Professional Training Q Junior College |~1 University Degree tZ3 Post Graduate Degree(s) Q What is your total household income (including income for all members of the family)? under 2000 • 1000 - 11999 • 2000 - 3999 • 12000 - 13999 • 4000 - 5999 • 14000 - 15999 • 6000 - 7999 • 16000 - 20000 • 8000 - 9999 • over 20000 • Comments? NOISE AMD TRAFFIC HEASURE'SEflT SU i^ 1ARY SHEET DAY- TIME: . LOCATION: FLOW CHARACTERISTIC: INTERRUPTED? YES j | HO ( i . e . , the presence of a stop s i gn , s igna l e t c . ) GRADE GREATER THAI! 2%; YES • NO • SHIELDING: PARKED CARS YES n NO • LARGE TREES YES LT NO • LARGE BUILDINGS YES • NO • OTHER YES • NO • DISTANCE OF POINT OF MOISE -EASlREHEilT FROM NEAREST PAVEMENT EDGE (FT) : NUMBER OF TRAVELED LATJES (BOTH HAYS): TRAFFIC VOLUME: CARS . (VPH) PICKUP ft PAMEL (VPH) TRUCKS (VPH) SI'SES • (VPH) MOTORCYCLES (VPH) TOTAL 10 MEASURED SPEEDS (MPH): OTHER ROAD AND TRAFFIC FEATURES THOUGHT TO BE SIGNIFICANT: ( s i gna l s , s i gns , pavement c o n d i t i o n , congest ion, pedestr ian cross ings ) ILLUSTRATE ON MAP PHYSICAL SITUATION (esp. t rees , w a l l s , embankments) WHICH MAY EFFECT NOISE. COMMENTS: 1 4 9 A P P E N D I X B : N O I S E M E A S U R E M E N T A N D I N D I C E S O u t l i n e S o u n d s a r e p h y s i c a l d i s t u r b a n c e s ( v i b r a t i o n s o r p r e s s u r e c h a n g e s ) i n a n e l a s t i c m e d i u m w h i c h p r o p a g a t e t h r o u g h l o n g i t u d -i n a l w a v e m o t i o n t o t h e e a r o f t h e l i s t e n e r . N o i s e i s u s u a l l y d e f i n e d a s u n d e s i r a b l e o r u n w a n t e d s o u n d s T h e a m b i e n t n o i s e i s t h e a l l - e n c o m p a s s i n g n o i s e a s s o c i a t e d w i t h a g i v e n e n v i r o n m e n t ; p a r t i c u l a r n o i s e s a r e t h o s e w h i c h a r e n o t i c e a b l e a s d i s t i n c t l y a p a r t f r o m t h e a m b i e n t n o i s e . T h e n o i s e l e v e l i s t h e m e a s u r e d s o u n d p r e s s u r e l e v e l , i n d e c i b e l s ( d B ) , o f a n y u n w a n t e d s o u n d , w h e r e t h e s o u n d p r e s s u r e l e v e l ( S P L ) , i n d e c i b e l s , i s d e f i n e d a s 2 0 t i m e s t h e l o g a r i t h m ( b a s e 1 0 ) o f t h e r a t i o o f t h e p r e s s u r e o f t h i s s o u n d t o t h e r e f e r e n c e p u r e s s u r e , u s u a l l y . 0 0 0 2 m i c r o b a r . S P L ( d B ) = 2 0 l o g 1 0 T h e d e c i b e l i s a u n i t o f l e v e l m e a s u r e m e n t w h e n t h e b a s e o f t h e l o g a r i t h m i s 1 0 a n d t h e m e a s u r e d q u a n t i t i e s c o n c e r n e d a r e p r o p o r t i o n a l t o p o w e r . S o u n d i s a f o r m o f e n e r g y o r p o w e r , a n d a m e a s u r e o f t h i s e n e r g y i s t h e s q u a r e o f t h e s o u n d p r e s s u r e . T h e r e f e r e n c e q u a n t i t y , z e r o d B , i s a b o u t t h e l e v e l o f t h e w e a k e s t s o u n d t h a t c a n b e h e a r d b y a p e r s o n w i t h g o o d h e a r i n g i n a n 2 e x t r e m e l y q u i e t l o c a t i o n . T h e s m a l l e s t a u d i b l e s o u n d h a s a s o u n d p r e s s u r e o f 0 0 0 0 2 m i c r o b a r s (1 b a r = 1 a t m o s p h e r i c 2 p r e s s u r e ; 1 m i c r o b a r = 1 d y n e / c m ) . A d e c i b e l i s a r e l a t i v e f p Y2 q u a n t i t y . T h e m e a s u r e o f p o w e r i s I k O j l o g / n r i r i 7 ) • I h e 1 U I * \J \J U CJ J s o u n d p r e s s u r e l e v e l i n d e c i b i e l s i s t h e r e f o r e I n d e a l i n g w i t h t h e m e a s u r e m e n t o f n o i s e , i t i s t h e s o u n d p r e s s u r e l e v e l i n d e c i b e l s w h i c h i s u s e d a n d n o t t h e a c t u a l v a l u e o f t h e p r e s s u r e i n m i c r o b a r s . T h i s i s d o n e t o e a s t t h e h a n d l i n g o f t h e w i d e r a n g e o f s o u n d p r e s s u r e s e n c o u n t e r e d . A d o u b l i n g o f s o u n d p r e s s u r e c o r r e s p o n d s t o a n i n c r e a s e i n t h e s o u n d p r e s s u r e l e v e l o f 6 d B . I n c o m b i n i n g t w o o r m o r e s e p a r a t e s o u n d p r e s s u r e l e v e l s t h e d e c i b e l v<a<lue:s c a n n o t b e a d d e d d i r e c t l y . R a t h e r t h e r e s u l t a n t s o u n d p r e s s u r e l e v e l i s d e t e r m i n e d f r o m t h e r e s u l t a n t o f t h e t w o s o u n d p r e s s u r e s . 1 5 1 R \ J 1 2 2 P , + P _ E x a m p l e : A d d t w o s o u n d p r e s s u r e l e v e l s o f 7 0 d B a n d 7 4 d B P 7 0 = 2 0 1 o g i o ( ^ b ( 3 2 - j 3 . 7 = l o g 1 0 V . 0 0 0 2 7 4 = 2 0 l o g 1 0 3 . 7 = l o g 1 0 V . 0 0 0 2 \ . 0 0 0 2 j ) 1 0 0 0 2 3 . 1 6 x 1 0 " 0 0 0 2 5 . 0 1 x 1 0 " P = . 6 2 8 P = 1 . 0 0 2 P R = J ( - 6 2 8 ) @ + (1 . 0 0 2 ) 1 . 1 8 2 0 l o g 10 \. 0 0 0 2 / = 2 0 l o g 5 . 9 x 1 0 .= 7 5 . 4 T h u s 7 0 d B + 7 4 d B = 7 5 . 4 d B . T h e u s e o f t a b l e s a l l o w s o n e t o r e a d o f f t h e a m o u n t t o b e a d d e d t o t h e h i g h e r i n i t i a l s o u n d p r e s s u r e l e v e l w i t h o u t g o i n g t h r o u g h t h e a b o v e c a l c u l a t i o n s . F o r a p o i n t s o u r c e ( e . g . a n i n d i v i d u a l t r u c k ) i n a f r e e f i e l d ( n o o b s t r u c t i o n s o r b o u n d a r y e f f e c t s ) s o u n d p r e s s u r e v a r i e s 1 5 2 i n v e r s e l y w i t h d i s t a n c e . T h u s f o r e a c h d o u b l i n g o f d i s t a n c e , s o u n d p r e s s u r e i s h a l v e d w i t h a r e s u l t a n t d e c r e a s e i n t h e s o u n d p r e s s u r e l e v e l o f 6 d B . H a l v i n g t h e d i s t a n c e b e t w e e n r e c e i v e r a n d s o u r c e w i l l r e s u l t i n a n i n c r e a s e o f 6 d B i n t h e s o u n d p r e s s u r e l e v e l . F o r a l i n e s o u r c e ( s t r e a m o f t r a f f i c ) ? i n a f r e e f i e l d , s o u n d p r e s s u r e v a r i e s i n v e r s e l y w i t h t h e s q u a r e r o o t o f t h e d i s t a n c e . E a c h d o u b l i n g o f t h e d i s t a n c e w i l l r e s u l t i n a d e c r e a s e o f 3 d B i n t h e s o u n d p r e s s u r e l e v e l . A g a i n , h a l v i n g t h e d i s t a n c e i n c r e a s e s t h e s o u n d p r e s s u r e l e v e l b y 3 d B . E x a m p l e s o f t h i s a t t e n u a t i o n o f s o u n d o v e r d i s t a n c e c a n b e s e e n i n f i g u r e s 5 t h r o u g h 7 . S o u n d p r e s s u r e l e v e l s a r e u s u a l l y m e a s u r e d o n m e t e r s w i t h a f l a t o r u n i f o r m f r e q u e n c y r e s p o n s e . T h e a p p a r e n t l o u d n e s s a t t r i b u t e d t o a s o u n d , h o w e v e r , i s a f u n c t i o n o f b o t h t h e s o u n d p r e s s u r e l e v e l a n d t h e f r e q u e n c y . T o t a k e t h i s i n t o e f f e c t w h e n m e a s u r i n g s o u n d p r e s s u r e l e v e l s i n a n a t t e m p t t o d u p l i c a t e h u m a n r e s p o n s e , i t i s n e c e s s a r y t o a d d e l e c t r i c a l w e i g h t i n g n e t w o r k s o r f i l t e r s t o r e d u c e t h e r e s p o n s e o f t h e m e t e r t o c e r t a i n f r e q u e n c i e s . T h e b a s i s f o r t h e s e w e i g h t i n g n e t w o r k s a r e t h e e q u a l l o u d n e s s c o n t o u r s o f R o b i n s o n a n d D a d s o n o n t h e e a r l i e r c u r v e s o f F l e t c h e r a n d M u n s o n . T h e s o u n d l e v e l o f a n o i s e t h e n b e c o m e s t h e w e i g h t e d s o u n d p r e s s u r e l e v e l o b t a i n e d b y u s i n g a m e t e r w h o s e w e i g h t i n g 3 c h a r a c t e r i s t i c s a r e s p e c i f i e d . T h e f r e q u e n c y r e s p o n s e o f t h e m o s t c o m m o n w e i g h t i n g n e t w o r k s a r e s h o w n i n F i g u r e 8 . S o u r c e : C.R. B r a g d o n , No i se Po l 1ut i o n . U n i v . o f P e n n s y l v a n i a P r e s s , 1 9 7 1 , p. 1 1 5 . 50 100 200 400 600 800 1,000 DISTANCE FROM SOURCE, IN FEET Typical continuous noise produced by surface ground transportation modes. I 600 2,000 F i g u r e 6. F a l l o f f o f C o n t i n u o u s T r a n s p o r t a t i o n N o i s e o v e r D i s t a n c e . i 4,000 5,000 S o u r c e : U .S . DOT " R e c o m m e n d a t i o n s f o r N o r t h e a s t C o r r i d o r T r a n s p o r t a t i o n , F i n a l R e p o r t " NT I S , S e p t . 1971 Distance from x of Lane in feet Noise reduction provided by various highway configurations. F i g u r e 7. F r e q u e n c y in H e r t z >-O N F i g u r e 8. F r e q u e n c y Re sponse C h a r a c t e r i s t i c s o f W e i g h t i n g N e t w o r k s . 1 5 7 M e a s u r e m e n t o f N o i s e T h e b a s i c i n s t r u m e n t o f a s o u n d m e a s u r i n g s y s t e m i s t h e s o u n d l e v e l m e t e r , a n a c c u r a t e p o r t a b l e m e t e r w h i c h r e a d s t h e s o u n d p r e s s u r e l e v e l i n t e r m s o f t h e s t a n d a r d r e f e r e n c e p r e s s u r e . I t w i l l u s u a l l y b e c o m p o s e d o f a n o m n i d i r e c t i o n a l m i c r o p h o n e , a n a d j u s t a b l e a m p l i f i e r , a c a l i b r a t e d a t t e n u a t o r , a n i n d i c a t i n g m e t e r , a n d e l e c t r i c a l w e i g h t i n g n e t w o r k s . T h e m i c r o p h o n e , t > r a n s f o r m s t h e c h a n g i n g s o u n d p r e s s u r e w a v e s i n t o e l e c t r i c a l v o l t a g e f l u c t u a -t i o n s w h i c h a r e a m p l i f i e d s u f f i c i e n t l y t o a c t u a t e a m e t e r o r r e c o r d e r . T h e m e t e r u s u a l l y r e a d s o v e r o n l y a s m a l l r a n g e , t h i s r a n g e b e i n g s e l e c t e d a n d a d j u s t e d b y t h e a t t e n u a t o r t o s u i t t h e s o u n d b e i n g m e a s u r e d . T h e w e i g h t i n g n e t w o r k s a r e e l e c t r i c a l c i r c u i t s w h i c h 4 p r o v i d e f o r v a r i o u s s e n s i t i v i t i e s t o s o u n d s o f d i f f e r e n t f r e q u e n c i e s . C a l i b r a t i o n s , w h i c h p r o d u c e s o u n d o f a k n o w n p r e s s u r e l e v e l a n d t o n e , a r e u s e d t o e n s u r e t h e s o u n d l e v e l m e t e r i s f u n c t i o n i n g p r o p e r l y . A f r e q u e n c y a n a l y z e r i s o f t e n u s e d t o d e t e r m i n e t h e f r e q u e n c y s p e c t r u m o f t h e n o i s e . I t c o n s i s t s o f a s e t o f i n d i v i d u a l l y a c t i v a t e d b a n d p a s s f i l t e r s , a t t e n u a t o r a n d a m p l i f i e r t o d r i v e a m e t e r . M a g n e t i c t a p e r e c o r d e r s a r e u s e d f o r r e c o r d i n g a n d s t o r i n g n o i s e e n c o u n t e r e d i n t h e f i e l d f o r l a t e r a n a l y s i s i n t h e l a b . T h e s t a t i s t i c a l d i s t r i b u t i o n a n a l y z e r i s u s e d t o b a n d a n a l y z e a n d s t a t i s t i c a l l y d i s t r i b u t e t h e r e c o r d e d s o u n d s i n t o c h a n n e l s o f a c e r t a i n b a n d w i d t h o v e r a r a n g e o f s o u n d p r e s s u r e l e v e l s , e . g . t h a t p e r c e n t a g e o f t h e s o u n d p r e s s u r e l e v e l s b e t w e e n 7 0 a n d 7 5 d B w i l l - 1 5 8 b e p l a c e d i n t h e 7 0 - 7 5 d B c h a n n e l , t h a t p e r c e n t a g e b e t w e e n 7 5 a n d 8 0 d B w i l l b e p l a c e d i n t h e 7 5 - 8 0 d B c h a n n e l , e t c . T h e a n a l y z e r c a n b e c a l i b r a t e d a n d a d j u s t e d t o h a n d l e a v a r i e t y o f r a n g e s a n d b a n d w i d t h s . R a t i n g S c a l e s A r a t i n g s c a l e d e s c r i b e s o n l y t h e n o i s e e x p o s u r e i t s e l f , e i t h e r i n a s i m p l e w a y s u c h a s t h e r e a d i n g o f t h e m a x i m u m A -w e i g h t e d s o u n d l e v e l d u r i n g a t r a n s i e n t n o i s y e v e n t , o r i n s o m e m o r e c o m p l i c a t e d m a n n e r t h a t m a y a c c o u n t f o r t h e t i m e v a r i a t i o n o f n o i s e a n a l y z e d i n t o f r e q u e n c y b a n d s . A r a t i n g p r o c e d u r e a t t e m p t s t o a c c o u n t f o r t h e c o n t e x t i * n h w _ h i c h t h e n o i s e s t i m u l u s i s e x p e r i e n c e d a n d u s u a l l y e n t a i l s t h e i n t r o d u c t i o n o f c o r r e c t i o n s f o r t h e c h a r a c t e r -i s t i c s o f t h e n o i s e ( p u r e t o n e , d u r a t i o n ) a n d f o r t h e p a r t i c u l a r 5 s i t u a t i o n ( t i m e o f d a y i t o c c u r r e d ) . T h e r a t i n g s y s t e m s d f c s c u s s e d b e l o w a r e b u t a f e w o f m a n y w h i c h h a v e b e e n p r o p o s e d o v e r t h e p a s t f e w y e a r s . E a c h s y s t e m o f f e r s s o m e t h i n g a l i t t l e d i f f e r e n t f r o m t h e o t h e r s a n d e a c h h a s i t s p r o p o n e n t s . 1 . T h e A - w e i g h t e d s o u n d l e v e l i s a r e l a t i v e l y o l d s y s t e m w h i c h a t t e m p t s t o m a k e t h e s o u n d l e v e l m e t e r r e s p o n d t o s o u n d s i n a m a n n e r m o r e l i k e t h e h u m a n e a r . L o w f r e q u e n c i e s ( b e l o w 5 0 0 H z ) a r e q u i t e s e v e r e l y d i s c r i m i n a t e d a g a i n s t i n t h e A - w e i g h t e d s y s t e m . T h i s i s a c c o m p l i s h e d t h r o u g h t h e u s e o f e l e c t r i c a l w e i g h t i n g 1 5 9 n e t w o r k s ' i n t h e s o u n d l e v e l m e t e r w h i c h a l t e r s i t s n o r m a l l y f l a t r e s p o n s e . O v e r t h e y e a r s n o s c a l e o r p r o c e d u r e h a s s h o w n t o b e c o n s i s t e n t l y b e t t e r t h a n t h e A - w e i g h t e d s o u n d l e v e l i n c o r r e l a t i o n , • • 6 w i t h s u b j e c t i v e r e s p o n s e . 2 . L o u d n e s s l e v e l . S . S . S t e v e n s a n d E . Z w i c k e r h a v e d e v e l o p e d m e t h o d s f o r c a l c u l a t i n g t h e t o u d n e s s o f a c o m p l e x n o i s e . B o t h m e t h o d s t a k e i n t o a c c o u n t t h e m a s k i n g o r i n h i b i t i n g o f o n e c o m p o n e n t o f a c o m p l e x n o i s e b y o t h e r c o m p o n e n t s ; Z w i c k e r ' s m e t h o d a l s o t a k e s i n t o a c c o u n t t h a t t h i s m a s k i n g i s a s y m m e t r i c ( f r e q u e n c i e s a b o v e t h e i n t e n s e b a n d a r e m a s k e d m o r e s o t h a n t h o s e b e l o w t h e b a n d ) . " F r e q u e n c y a n a l y s i s i s p e r f o r m e d a n d a l o u d n e s s i n d e x f o r e a c h b a n d i s d e t e r m i n e d a s a f u n c t i o n o f b a n d s o u n d p r e s s u r e l e v e l a n d f r e q u e n c y ; t h i s i n d e x r e p r e s e n t s t h e b a n d ' s c o n t r i b u t i o n t o t h e t o t a l l o u d n e s s . T h e s e i n d i c e s a r e t h e n s u m m e d , e a c h w i t h v a r i o u s w e i g h t i n g f a c t o r s t o r e f l e c t t h e f a c t t h a t t h e b a n d w i t h t h e l o u d e s t i n d e x w i l l m a s k t h e c o n t r i b u t i o n s o f o t h e r b a n d s . T h i s s u m b e c o m e s a c o m p o s i t e l o u d n e s s i n d e x , S , a n d i s c o n v e r t e d t o a l o u d n e s s l e v e l b y t h e f o r m u l a P = 4 0 + 1 0 l o g ^ Q S . 3 . T h e P e r c e i v e d N o i s e L e v e l ( P N L ) o f K r y t e r i s a s p i n o f f o f t h e l o u d n e s s l e v e l a n d i s c a l c u l a t e d i n m u c h t h e s a m e w a y . T h e f e w d i f f e r e n c e s o c c u r m a i n l y i n t h e w a y t h a t i n d i v i d u a l b a n d l o u d n e s s i n d i c e s a r e c o m p u t e d . I n s t e a d o f a l o u d n e s s i n d e x , S , K r y t e r a r r i v e s a t a n i n d e x o f ' p e r c e i v e d n o i s i n e s s ' ( u n i t i s t h e n o y ) w h i c h i s t h e n u s e d i n t h e s a m e e q u a t i o n a s a b o v e t o p r o d u c e t h e p e r c e i v e d 160 n o i s e l e v e l ( u n i t s a r e P N d B ) . T h e P N L i s u s e d f r e q u e n t l y i n a n a l y z i n g a i r c r a f t n o i s e . 4 . T h e N o i s e a n d N u m b e r I n d e x ( N N I ) w a s d e v e l o p e d d u r i n g t h e c o u r s e o f a s o c i a l s u r v e y o u t s i d e L o n d o n ( H e a t h r o w ) A i r p o r t t o d e t e r m i n e t h e a s p e c t s o f a i r c r a f t n o i s e w h i c h w e r e m o s t a n n o y i n g . T h e W i l s o n R e p o r t d e f i n e d N N I a s " a c o m p o s i t e m e a s u r e t a k i n g i n t o a c c o u n t t t h e a v e r a g e p e a k n o i s e l e v e l a s w e l l a s t h e 7 n u m b e r o f a i r c r a f t h e a r d i n a s p e c i f i e d p e r i o d . " N N I = ( a v e r a g e p e a k n o i s e l e v e l ) + 1 5 l o g N - 8 0 . T h e a v e r a g e p e a k n o i s e l e v e l w a s d e f i n e d a s N 01°ho (ir) £ ' i L / 1 0 1 0 w h e r e L w a s t h e p e a k n o i s e l e v e l i n P N d B ( t h e u n i t s o f P e r c e i v e d N o i s e L e v e l ) o c c u r r i n g d u r i n g t h e p a s s a g e o f e a c h a i r c r a f t a n d N w a s t h e n u m b e r o f a i r c r a f t h e a r d i n a s p e c i f i e d p e r i o d . 5 . T h e T r a f f i c N o i s e I n d e x ( T N I ) i s a w e i g h t e d c o m b i n a t i o n o f t h e a v e r a g e ' b a c k g r o u n d ' l e v e l a n d t h e a v e r a g e ' p e a k ' l e v e l f o u n d u s i n g t h e b a s e m e a s u r e o f A - w e i g h t e d s o u n d l e v e l . T N I = 4 ( L 1 Q - L 9 Q ) + L 9 Q - 3 0 . T h e s o u n d l e v e l s L a n d L w e r e t h o s e s o u n d l e v e l s e x c e e d e d 1 0 7 0 1 0 % a n d 9 0 % o f t h e t i m e r e s p e c t i v e l y . T h e f i r s t t e r m e x p r e s s e s t h e r a n g e o f t h e n o i s e e n v i r o n m e n t w h i l e t h e s e c o n d r e p r e s e n t s t h e b a c k g r o u n d n o i s e l e v e l . 6 . T h e N o i s e P o l l u t i o n L e v e l ( N P L ) w a s d e v e l o p e d b y -R o b i n s o n a n d i s b a s e d o n t w o t e r m s , o n e a c c o u n t i n g f o r t h e a n n o y a n c e d u e t o f l u c t u a t i o n s o f n o i s e l e v e l a n d t h e o t h e r r e p r e s e n t i n g t h a t a n n o y a n c e d u e t o t h e c o n t i n u o u s n o i s e l e v e l . N P e g w h e r e L = t h e ' e n e r g y ' m e a n o f t h e n o i s e l e v e l o v e r a e g s p e c i f i e d p e r i o d 0" = t h e s t a n d a r d d e v i a t i o n o f t h e i n s t a n t a n e o u s n o i s e l e v e l o v e r t h e s a m e p e r i o d k = a c o n s t a n t d e t e r m i n e d b y o b t a i n i n g t h e b e s t c o r r e l a t i o n o f L w i t h s u b j e c t i v e r e s p o n s e N P J . ( R o b i n s o n f o u n d k t o b e 2 . 6 ) . T h e t e r m , L , i s d e t e r m i n e d l a r g e l y b y t h e a v e r a g e i n t e n s i t y o f t h e n o i s e a n d i s d e r i v e d f r o m a s t a t i s t i c a l a n a l y s i s o f t h e n o i s e h i s t o r y . L = 1 0 l o g , n e g 5 1 0 l C i o L | t | / l l > dt w h e r e L ( t ) = t h e n o i s e l e v e l i n d B A a s a f u n t i o n o f t i m e T = t h e t i m e p e r i o d i n v o l v e d . 1 6 A s c a n b e s e e n , t h e v a r i o u s r a t i n g s c h e m e s , b a s e d o n p h y s i c a l m e a s u r e m e n t s o f n o i s e , d i f f e r g r e a t l y i n t h e a m o u n t o f c a l c u l a t i o n r e q u i r e d . T h e c h o i c e o f a n y r a t i n g f o r a p a r t i c u l a r p u r p o s e s h o u l d t h u s c o n s i d e r t h e t r a d e o f f s i n v o l v e d i n c o m p u t i n g t h e i n d e x a n d t h e p r e c i s i o n a n d a c c u r a c y i n p r e d i c t i o n o f r e s p o n s e t o n o i s e . B e c a u s e o f i t s r e l a t i v e s i m p l i c i t y , e a s e o f a p p l i c a t i o n , a n d l o n g h i s t o r y o f r e l a t i v e a c c u r a c y , t h e A - w e i g h t e d s o u n d l e v e l h a s o f t e n b e e n c h o s e n a s t h e s t a n d a r d s o u n d l e v e l m e a s u r i n g s y s t e m . I t w a s f o r a l l o f t h e a b o v e r e a s o n s t h a t i t w a s u s e d i n t h i s s t u d y . 1 6 3 F O O T N O T E S * M . D . H a r m e l i n k , " N o i s e a n d V i b r a t i o n C o n t r o l f o r T r a n s p o r t a t i o n S y s t e m s " , D e p t . o f H i g h w a y s , O n t a r i o , R e p o r t N o . R R 1 6 8 , 1 9 7 0 , p . 1 . 2 I b i d . , p . 2 . 3 I b i d . , p . 4 . 4 I b i d . , p . 5 . 5 T h e o d o r e S c h u l t z , C o m m u n i t y N o i s e R a t i n g s , A p p l i e d S c i e n c e P u b l i s h e r s L t d . , L o n d o n , 1 9 7 2 , p . 1 0 . 6 I b i d . , p . 16. S i r A l a n W i l s o n , N o i s e : F i n a l R e p o r t o f t h e  C o m m i t t e e o n t h e P r o b l e m o f N o i s e , H e r M a j e s t y ' s S t a t i o n e r y O f f i c e , L o n d o n , J u l y , 1 9 6 3 . 

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