Open Collections

UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

Design criteria for the acoustical environment in open plan offices Matić, Vojislava 1976

Your browser doesn't seem to have a PDF viewer, please download the PDF to view this item.

Item Metadata

Download

Media
831-UBC_1976_A7_3 M38.pdf [ 8.52MB ]
Metadata
JSON: 831-1.0093722.json
JSON-LD: 831-1.0093722-ld.json
RDF/XML (Pretty): 831-1.0093722-rdf.xml
RDF/JSON: 831-1.0093722-rdf.json
Turtle: 831-1.0093722-turtle.txt
N-Triples: 831-1.0093722-rdf-ntriples.txt
Original Record: 831-1.0093722-source.json
Full Text
831-1.0093722-fulltext.txt
Citation
831-1.0093722.ris

Full Text

DESIGN CRITERIA FOR THE ACOUSTICAL ENVIRONMENT IN OPEN PLAN OFFICES by VOJISLAVA MATIC D i p l . Ing. Arch. U n i v e r s i t y of Zagreb, Y u g o s l a v i a , 1966 THESIS SUBMITTED IN PARTIAL FULFILLMENT THE REQUIREMENTS FOR THE DEGREE OF MASTER ,'OF ARCHITECTURE i n the Department of A r c h i t e c t u r e We accept t h i s t h e s i s as conforming to the r e q u i r e d standard THE UNIVERSITY OF BRITISH COLUMBIA October, 1976 (c) V o j i s l a v a Matic i i In presenting t h i s thesis i n p a r t i a l f u l f i l l m e n t of the requirements f o r an advanced degree at the University of B r i t i s h Columbia, I agree that the Library s h a l l make i t f r e e l y a v a i l a b l e for reference and study. I further agree that permission for extensive copying of t h i s thesis for s c h o l a r l y purposes may be granted by the Head of my Department or by his representatives. It i s understood that copying or p u b l i c a t i o n of t h i s thesis f o r f i n a n c i a l gain s h a l l not be allowed without my written permission. Department of Architecture The University of B r i t i s h Columbia 2075 Wesbrook Place, Vancouver, B.C., V6T 1W5 Canada Date October 6, 1976 i i i ABSTRACT The concept of open planned o f f i c e space i s becoming more and more popular. However, there i s a serious problem associated with t h i s concept, that being the attainment of speech privacy. Since speech privacy i s a very important issue for some types of o f f i c e work the main objective of t h i s thesis i s to study the acoustic requirements of the open plan o f f i c e . In order to improve o f f i c e working conditions, i t was decided to c o r r e l a t e e x i s t i n g t h e o r e t i c a l findings on general o f f i c e noise and sc r e e n / c e i l i n g a c o u s t i c a l performance with actual s i t u a t i o n s from seven o f f i c e layout samples taken i n the Vancouver, B.C., area. Of the people who have been doing research i n t h i s s p e c i f i c area, Geiger and Hamme in Ann Arbor, Michigan, appear to be the furthest advanced. The purpose of th i s thesis i s to extend the work of Geiger and Hamme as a contribution to the e x i s t i n g findings of the acoustical c h a r a c t e r i s t i c s of open plan o f f i c e space. To achieve the goals of t h i s thesis, the h i s t o r i c a l back-ground of o f f i c e buildings, a study of current space require-ments and the importance of speech privacy are examined. Further t h e o r e t i c a l issues include an explanation of acou s t i c a l performance of s p e c i f i c b u i l d i n g elements. The objective of th i s discussion i s to expand the data base of a number of aco u s t i c a l parameters including average sound l e v e l s , a r t i c u l a -t i o n index and scr e e n / c e i l i n g attenuation values, i n order to further develop e x i s t i n g a c o u s t i c a l design c r i t e r i a . The study concludes that while there i s indeed a need for speech privacy i n open plan o f f i c e s , the degree of need varies considerably with the l e v e l of c o n f i d e n t i a l i t y . The research confirms that the greater the need for speech privacy, the less s a t i s f a c t o r y i s the open o f f i c e concept. Further study i n t h i s f i e l d i s c l e a r l y indicated and includes further exploration of the following f a c t o r s : 1. The d e f i n i t i o n of people's concerns regarding speech privacy. 2. The economic factors and t h e i r implications. 3. The establishment of environmental maxims. Signed by Research Advisor V TABLE OF CONTENTS Page CERTIFICATES i i ABSTRACT i i i TABLE OF CONTENTS v LIST OF TABLES v i i LIST OF FIGURES v i i i GLOSSARY x ACKNOWLEDGEMENTS x i v 1. INTRODUCTION 1 1.1 PURPOSE OF RESEARCH STUDY 2 1.2 METHOD OF RESEARCH STUDY 4 1.3 REFERENCE 5 2. SURVEY OF THE LITERATURE 6 2.1 THE HISTORICAL BACKGROUND OF OFFICE BUILDINGS 7 2.2 ARCHITECTURAL SPACIAL AND SPEECH PRIVACY CRITERIA^ ANALYSIS 12 2.3 ACOUSTICAL PERFORMANCE OF SPECIFIC BUILDING ELEMENTS 26 2.4 GENERAL ACOUSTICAL GUIDELINES 37 2.5 REFERENCE 42 3. SURVEY OF THE NOISE CLIMATES IN OPEN-PLAN OFFICES 46 3.1 DESCRIPTION OF OFFICES STUDIED 47 3.2 SUBJECTIVE TESTING AND OBJECTIVE MEASUREMENTS 64 3.2.1 A c o u s t i c a l C o n s i d e r a t i o n s and Occupant Q u e s t i o n n a i r e 64 3.2.2 Measurement o f the A c o u s t i c a l C h a r a c -t e r i s t i c s o f t h e O f f i c e s 75 3.2.3 R e s u l t s and A n a l y s i s o f t h e Data . . . . 87 v i Page 3.3 COMPARISON OF THE OFFICE SAMPLE STUDIES TO APPROVED ACOUSTIC GUIDELINES 113 3.3.1 Acceptable C r i t e r i a f or Noise i n Large Offic e s (E.C. Keighley) 113 3.3.2 Test Method PBS-C.l and PBS-C.2 (U.S. Public Building Services) 114 3.3.3 Si m p l i f i e d A r t i c u l a t i o n Test (J.D. G r i f f i t h s ) 121 3.4 CONCLUSION OF THE SURVEY 124 3.5 REFERENCE 128 4. CONCLUSIONS AND RECOMMENDATIONS 129 4.1 SUMMARY OF DATA 130 4.2 SUMMARY OF CONCLUSIONS 132 4.3 RECOMMENDATIONS FOR FURTHER STUDY 135 4.4 CONCLUDING REMARKS 137 REFERENCE MATERIAL BIBLIOGRAPHY 140 APPENDICES 148 A . l THE QUESTIONNAIR SAMPLE 148 A. 2 THE ANALYSIS OF DATA 151 BIOGRAPHICAL INFORMATION , t . • • v i i LIST OF TABLES Table P a ^ e 2 . 1 - 2 . 2 Suggested c r i t e r i a for noise control (in terms of SIL) - maximum permissible values of speech-interference l e v e l s (from Handbook of Noise Measurement General Radio Company) 24 2 . 3 The absorption c o e f f i c i e n t of d i f f e r e n t surface f i n i s h e s (from FRIBA) 29 3 . 1 Summary chart of the questionnaires, showing r e s u l t s obtained regarding: physical environment, location of sound sources, i n d i v i d u a l work a c t i v i t i e s , s a t i s f a c t i o n of the observer and general employees expectation 73 3 . 2 Summary chart on the r e s u l t s of the screen attenuation tests for each o f f i c e sample surveyed 122 3 . 3 - 3 . 6 b The samples of the analysis of data for each o f f i c e sample surveyed 152 v i i i LIST OF FIGURES Figure Page 2.1 A general look at old and new types' of o f f i c e b u i l d i n g 9 2.2 A range to su i t most o f f i c e tasks 13 2.3-2.6 D i f f e r e n t choices of optimum s i z e and' shape within e x i s t i n g o f f i c e plans 15 2.7-2.9 Noise c r i t e r i a (from the information compiled by Parkin, P.H.) 20 2.10-2.13 Several factors influencing speech privacy, while developing a r a t i n g method (from the information compiled by Cavanough, J.W.) 22 2.14 Graph i l l u s t r a t i n g dependence of absorption on angle of incidence (from Geiger & Hamme) 27 2.15 Several samples of additional sound absorbing materials such as b a f f l e s onto the c e i l i n g 35 2.16 & 2.17 Two samples for the interzone attenua-ti o n c e i l i n g / s c r e e n tests (from Geiger & Hamme) 39 3.1 -3.4b The e x i s t i n g o f f i c e plans survey samples 49 3.5-3.8 Explanation of measurement locations as to each sample layout surveyed 75 3.9-3.11 Equipment used 80 3.12 Sample of word rhyming test (by J.D. G r i f f i t h s ) 84 3.13 Screen testing positions 86 3.14-3.19 Graphical presentation of o f f i c e noise taperecordings 89 3.20-3.25 D i s t r i b u t i o n graph, showing cumulative diagram of sounds analyzed 96 3.26 - 3.29b The octave band' sound l e v e l s , showing the spectrum shape for each sample o f f i c e surveyed 103 ix Figure Page 3.30 Summary chart of objective screen/ c e i l i n g tests showing the actual s i t u a t i o n of attenuation values 115 3.31-3.34 The e x i s t i n g o f f i c e s c r e e n / c e i l i n g attenuation tests and c o r r e l a t i o n to the t h e o r e t i c a l f i n d i n g by Geiger & Hamme tests approved 116 X GLOSSARY OF TERMS ARTICULATION INDEX (Al) - A numerically calc u l a t e d measure of the i n t e l l i g i b i l i t y of transmitted or processed speech. The a r t i c u l a t i o n index can range i n magnitude between 0 and 1.0. If the A l i s less than 0.1, speech i n t e l l i g i b i l i t y i s generally low. If i t i s above 0.6, speech i n t e l l i g i b i l i t y i s generally high. A-WEIGHTED SOUND LEVEL (dBA) - A quantity, i n decibels, read from a standard sound-level meter that i s switched to the "A" weighting network. The A-weighting network discriminates against lower frequencies according to a r e l a t i o n s h i p approxi-mating the auditory s e n s i t i v i t y of the human ear at moderate sound l e v e l s . The A-weighted sound l e v e l measures approximately the r e l a t i v e "noisiness" and "annoyance" of many common sounds. BACKGROUND NOISE - The t o t a l of a l l noise i n a system of s i t u a t i o n , independent of the presence of the desired s i g n a l . CONTINUOUS SOUND SPECTRUM - A continuous sound spectrum i s comprised of components which are continuously d i s t r i b u t e d over a frequency region. DECIBEL - The unit i n which the leve l s of various a c o u s t i c a l q u antities are expressed. Ty p i c a l quantities so expressed are sound pressure l e v e l , sound power le v e l and d i r e c t i v i t y index. DIRECTIVITY INDEX - In a given d i r e c t i o n from a sound source, the difference i n decibels between (a) the sound-pressure l e v e l produced by the source i n that d i r e c t i o n , and (b) the space-average sound-pressure l e v e l of that source, measured at the same distance. FREQUENCY - The number of o s c i l l a t i o n s per second (a) of a sine-wave of sound, and (b) of a v i b r a t i n g s o l i d object; now expressed i n hertz (abbreviation Hz), formerly i n cycles per second (abbreviation cps). HERTZ - See frequency. INVERSE-SQUARE LAW - The inverse-square law describes that acoustic s i t u a t i o n where the mean-square sound pressure changes in inverse proportion to the square of the distance from the source. Under t h i s condition the sound-pressure l e v e l decreases 6 decibels with each doubling of distance from the source. See also spherical divergence. INTERZONE ATTENUATION - The spreading losses incurred by propa-gation a reference point 3 feet from a source and the receiving work st a t i o n , or the frequency-dependent attenuations produced by the shadow of a screen (nominally, 9 to 12 feet from a source). x i LEVEL - The l e v e l of an ac o u s t i c a l quantity (e.g. sound pressure), in decibels, i s 10 times the logarithm (base 10) of the r a t i o of the quantity to a reference quantity of the same physical kind - as long as the quantity i s proportional to power. LOUDNESS - (1) A l i s t e n e r ' s perception of the in t e n s i t y of a strongly-audible sound or noise, (2) the fact o r ri by which a constant-intensity sound or noise exceeds, i n the judgment of a l i s t e n e r , the loudness of a 1000 Hz tone heard at a sound pressure 40 dB above threshold. The unit i s the sone. See also loudness l e v e l . MASKING - The r a i s i n g of the threshold of hearing to a p a r t i c u l a r sound due to the presence of an addit i o n a l sound. NOISE CRITERIA CURVE OR LEVEL (NC) - A family of curves that describe preferred noise l e v e l s i n terms of t y p i c a l frequen-c i e s . (See Noise & Vibration Control, Leo Beranek.) An NC-20 i s very quiet; NC-40 approximates a t y p i c a l active o f f i c e ; an NC-70 approximates a noisy s t r e e t . NOISE LEVEL - See sound l e v e l . (3CTAVE BAND - A l l of the components, i n a sound spectrum, whose frequencies are between two sine wave components separated by an octave, such that the center frequency of one octave band i s exactly twice that of the preceeding band. OCTAVE-BAND SOUND PRESSURE LEVEL - The integrated sound pres-sure l e v e l of only those sine-wave components in a s p e c i f i e d octave band, f o r a noise or sound having a wide spectrum. PEAK SOUND PRESSURE - The maximum instantaneous sound pressure (a) f o r a transient or impulsive sound of short duration i n time, or (b) i n a s p e c i f i e d time i n t e r v a l f or a sound of long duration. PERCEIVED NOISE LEVEL (PNL) - The l e v e l i n dB assigned to a noise by means of a c a l c u l a t i o n procedure that i s based on an approximation to subjective evaluations of "noisiness". PITCH - A l i s t e n e r ' s perception of the frequency of a pure tone; the higher the frequency, the higher the p i t c h . REVERBERATION - The persistence of sound i n an enclosed space, as a r e s u l t of multiple r e f l e c t i o n s , a f t e r the sound source has stopped. SCREEN SHADOWING - The space near a screen or ba r r i e r where sound that i s generated i n an adjoining work station'cannot enter without bending around the edges of the screen. SCREEN SHADOWING POTENTIAL - The maximum sound attenuation attainable for any given c e i l i n g / s c r e e n combination. For x i i c e i l i n g evaluations, the dimensions of the screen are standar-dized and flanking r e f l e c t i o n from v e r t i c a l surfaces are mini-mized . SOUND-ABSORPTION COEFFICIENT (ABSORPTION COEFFICIENT) - The sound-absorbing a b i l i t y of a surface i s given in terms of a sound-absorption c o e f f i c i e n t . This c o e f f i c i e n t i s defined as the f r a c t i o n of incident sound energy absorbed or .otherwise not r e f l e c t e d by the'surface. Unless otherwise s p e c i f i e d , a d i f f u s e sound f i e l d i s assumed. The values of sound-absorption c o e f f i c i e n t usually range from about 0.01 for marble s l a t e to about 1.0 for long absorbing wedges such as are used i n ane-choic chambers. SOUND LEVEL (NOISE LEVEL) - The sound pressure l e v e l obtained by use of a sound l e v e l meter that i s used f o r the measurement of noise and sound leve l s i n a s p e c i f i e d manner. SOUND POWER - Of a source of sound, the t o t a l amount of acou-s t i c a l energy radiated into the atmospheric a i r per unit time. SOUND POWER LEVEL - The l e v e l of sound power i n decibels averaged over a period of time, the reference being 10~"12 watts. SOUND PRESSURE - (1) The minute f l u c t u a t i o n s i n atmospheric pressure which accompany the passage of a sound wave; the pressure f l u c t u a t i o n s on the tympanic membrane are transmitted to the inner ear and give r i s e to the sensation of audible sound. (2) For a steady sound, the value of the sound pressure averaged over a period of time. (3) Sound pressure i s usually measured (a) i n dynes per square centimeter (dyne/cm2), or (b) in newtons per square meter (N/m2). 1 N/m2 = 10 dyne/cm2 10-5 times the atmospheric pressure. SOUND PRESSURE LEVEL - The l e v e l of sound pressure in decibels squared and averaged over a period of time, the reference being the square of 2 x 10-5 newtons per square meter. SOUND TRANSMISSION CLASS (STC) - The preferred single f i g u r e r a t i n g system designed to.give an estimate of the sound i n s u l a -t i o n properties of a p a r t i t i o n or a rank ordering of a ser i e s of p a r t i t i o n s . I t i s intended for use pr i m a r i l y when speech and o f f i c e noise constitute the p r i n c i p a l noise problem. SPECTRUM - Of a sound wave, the descr i p t i o n of i t s r e s o l u t i o n i n t o components, each of d i f f e r e n t frequency and (usually) d i f f e r e n t amplitude and phase. SPEECH-INTERFERENCE LEVEL (SIL) - A ca l c u l a t e d quantity p r o v i -ding a guide to the i n t e r f e r i n g e f f e c t of a noise on speech. The speech-interference l e v e l i s the arithmetic average of the octave-band sound-pressure l e v e l s of the noise in the most important part of the speech frequency range. The l e v e l s - i n the three octave-frequency bands centered at 500, 1000 and 2000 Hz are averaged to determine the speech-interference leve. x i i i SPEECH PRIVACY - A quality of an acoustical environment where one i s not disturbed by a conversation occurring outside the immediate work s t a t i o n . It i s a personal evaluation. CONFIDENTIAL SPEECH PRIVACY - A quality of an acoustical environment where one cannot understand the sense of a conver-sation outside the immediate work s t a t i o n . SPEECH PRIVACY POTENTIAL (SSP) - A single number r a t i n g which qua n t i f i e s the l e v e l of speech privacy between given distances. THIRD-OCTAVE BAND - A series frequency bands whose center frequencies have a r a t i o of 2 1/-* (approximately 1.26). The cut-off frequencies of 891 Hz and 1123 Hz define a third-octave band with center frequency 1000 Hz. xiv ACKNOWLEDGEMENTS A great many people have contributed to this thesis research. The managers of the o f f i c e sample studies have been most generous i n providing assistance i n the survey c o l l e c -tions and information for t h i s study. The members of the committee and the other advisors from the University of B.C. or outside provided the writer with excellent advice and invaluable assistance i n expanding the concept. Their broad range of s k i l l s and comments on the work were instruments in the completion of t h i s t h e s i s . The author i s deeply g r a t e f u l to Dr. A.J.. Price, A s s i s -tant Professor, who has been w i l l i n g to review the materials outside the t r a d i t i o n a l d e f i n i t i o n of his f i e l d . His c r i t i c a l help and knowledge were most useful in t h i s study. Many thanks, to Miss G. Melanson f o r her willingness to expedite typing of thi s thesis research. V INTRODUCTION 1.1 PURPOSE OF RESEARCH STUDY 1.2 METHOD OF RESEARCH STUDY 1.3 REFERENCE 2 1.1 PURPOSE OF RESEARCH STUDY The open plan o f f i c e i n i t s contemporary form - with a l l l e v e l s of s t a f f i n one large space - has been used more and more during the l a s t decade, mainly because of advantages in organizational f l e x i b i l i t y . However, i n such o f f i c e s protec-tion from disturbing noise and privacy of speech cannot be obtained in conventional ways. From the writer's experience in o f f i c e planning, i t was r e a l i z e d that the degree of privacy required i s a major concern (1). Privacy depends very c r i t i c a l l y on small decibel changes in e i t h e r the attenuation of speech between work stations or the background noise l e v e l (2). To achieve s a t i s f a c t o r y acou-s t i c a l privacy i n an open plan o f f i c e , two conditions must be met. The f i r s t i s good speech i n t e l l i g i b i l i t y within each work s t a t i o n . The second i s that intrusions of sounds and speech must be rendered u n i n t e l l i g i b l e from outside the working area. Conversely, speech should be private and not overheard. This research examines the acoustical environment of an open plan o f f i c e and discusses the problems and the elements that can be u t i l i z e d to obtain acceptable r e s u l t s . The problems of o f f i c e acoustics and noise control are i n t e r r e l a t e d and interdependent. Acoustical problems in contemporary open plan o f f i c e s generally include the following: (1) Space r e l a t i o n s h i p s with respect to noise s e n s i t i v i t y , e.g. the noisy equipment should be concentrated in s p e c i f i c areas of the o f f i c e f l o o r and surrounded with a maximum amount of sound-absorptive treatment. (2) Space r e l a t i o n s h i p s with respect to speech privacy or a c o u s t i c a l screening requirements, e.g. the l o c a t i o n of screens between work s t a t i o n s . (3) The consideration of a l l surfaces surrounding the o f f i c e space and the importance of high sound absorption. (4) D i s t r i b u t i o n of moderately noisy o f f i c e equipment should be as uniform as possible a l l over the o f f i c e space since open plan o f f i c e s need a r e l a t i v e l y high masking sound l e v e l . The reason f o r including the problem of noise c o n t r o l i n t h i s research project i s . t o expand the data base of e x i s t i n g t h e o r e t i c a l findings and to further develop acoustical design c r i t e r i a in p h y s i c a l l y measurable terms. 4 1.2 METHOD OF RESEARCH STUDY It i s necessary to state a quantitative d e f i n i t i o n of both "adequate" privacy and the necessary c r i t e r i a for pre-d i c t i n g a c c e p t a b i l i t y in a t y p i c a l f i e l d s i t u a t i o n (4). The problem i s to produce acceptable speech privacy between work zones. The findings of t h i s study w i l l be correlated with the a c o u s t i c a l performance guideline s p e c i f i c a t i o n PBS - C . l + PBS - C.2 for U.S. federal o f f i c e b u i l d i n g s . The tests of interzone privacy are applicable primarily, but not e x c l u s i v e l y , to open plan o f f i c e s and introduce the concept of Speech Privacy P o t e n t i a l (SPP), a single number r a t i n g which quantifies the l e v e l of speech privacy between given points (5). The main task of this study i s to determine the privacy needs i n the space allocated (6). This study analyses and documents the speech patters of seven d i f f e r e n t o f f i c e f l o o r layouts. A study of the subjective e f f e c t s of noise described by E.F. Keighley (7), indicates that there are consistent i n d i v i d u a l differences i n noise tolerance and these also play some part i n determining the i n d i v i d u a l ratings (8). The survey of e x i s t i n g o f f i c e s (seven f l o o r layouts) i n t h i s study w i l l f a m i l i a r i z e the reader with the major components of each o f f i c e i n terms of the functional requirements of o f f i c e landscaping, the r e l a t i v e work status of the i n d i v i d u a l s and the i n d i v i d u a l space needs. Data i s obtained through a standardized questionnaire and the experimental measurements. The degree of privacy predicted, the measured subjective response of the occupants and objective a c o u s t i c a l measurements of the samples are used as a general guide to environmental standards. 5 1.3 REFERENCE 1. Williams, C Aural Speaker Recognition and  Speech Communication Systems  Evaluation. ICA, 21C3, Budapest, 1971. 2. Young, R.W. Crocker, M.J. Price, A.J. A. Denes, P.B. Revision of the Speech-Privacy  C a l c u l a t i o n . The Journal of the Acoustical Society of America, Vol. 37, Mo. 1, 1965. Noise and Noise Control. Vol. 18901 p. 248 C.R.C. Press Inc. Cranwood Parkway, Cleveland, Ohio 44128, U.S.A. On Line Computing i n Speech Re- search ( B e l l Telephone Laboratories) ICA: A23: Liege 7-14, September, 1965. 5. Geiger & Hamme (1) Test Method PBS-C1 for the d i r e c t measurement of speech privacy p o t e n t i a l (SPP) based on objective judgement. U.S. General Service Administration, August, 19, 1972. (2) Test • Method PBS-C2 for the suf-f i c i e n t v e r i f i c a t i o n of speech privacy p o t e n t i a l based on objec-t i v e measurements, including methods of f u n c t i o n a l interzone attenuation and NC-background. 6. Williams, C.E. (3) Guide for Ac o u s t i c a l Performance  S p e c i f i c a t i o n of an integrated c e i l i n g and background system. U.S. General Service Administration, August, 1972. Aural Speaker Recognition and  Speech Communication System  Evaluation. ICA, 21C3, Budapest, 1971. 7. Keighley,•E.F. The Determination of A c c e p t a b i l i t y  C r i t e r i a for O f f i c e Noise. Journal of Sound and V i b r a t i o n . (1966) r ( l ) 73-87. L i c k l i d e r , J.C.R, On the Process of Speech Percep- ti o n . Journal of Acoustical Society of America, Vol. 24, No. 6, November, 1952. SURVEY OF THE LITERATURE 2.1 THE HISTORICAL BACKGROUND OF OFFICE BUILDINGS 2.2 ARCHITECTURAL SPACIAL AND SPEECH PRIVACY CRITERIA ANALYSIS 2.3 ACOUSTICAL PERFORMANCE OF SPECIFIC BUILDING ELEMENTS 2.4 GENERAL ACOUSTICAL GUIDELINES 2.5 REFERENCE 7 2.1 THE HISTORICAL BACKGROUND OF OFFICE BUILDINGS Styles of both a r c h i t e c t u r a l and i n t e r i o r design have been conveniently assigned to h i s t o r i c a l categories, but a l l have been products of c u l t u r a l and s o c i a l s i t u a t i o n s which are c l e a r l y expressed i n building forms and i n t e r i o r f urnishings. Architecture, h i s t o r i c a l l y , has always shown a richness and c l a r i t y of expression. The h i s t o r y of o f f i c e building i s no exception to t h i s ; i t shows c l e a r l y the change of functions since o f f i c e s became an important part of modern working l i f e . The Origin and Growth of O f f i c e s . Ever since o f f i c e s have existed part of the work was in d i r e c t contact with the p u b l i c , and part depends on simultaneous co-operation with other employees. At the same time, being able to have a room of one's own has been always considered a p r i v i l e g e . The elementary psychology of power proves that i t has always been important to make i t d i f f i c u l t to gain access to "the boss" (1). Therefore, h i s t o r i c a l l y there has been a d i r e c t proportional r e l a t i o n s h i p between privacy and the rungs of the h i e r a r c h i c a l ladder. Thus, privacy was regarded as a status symbol. Today, however, i t i s quite possible to c a l i b r a t e privacy need according to p r a c t i c a l demands, rather than based on prestige (2). S c i e n t i s t s are studying the various types of s p a t i a l re-l a t i o n s h i p s between the people who work in o f f i c e s and the nature of t h e i r work (3). User needs are the basic r e q u i s i t e f o r any design problem (4). With r a p i d l y changing technology, economy, and s o c i a l conditions these needs also change (5). The o f f i c e design 8 process i s c h a r a c t e r i s t i c a l l y determined by the s p e c i f i e d u s e r - c l i e n t ' s needs (6). However, i t i s fa s c i n a t i n g to note that when Adler and Sullivan.were designing the famous Sc h i l e r Building in Chicago, the client-owners v/ere uncertain whether the building should be an o f f i c e building or a hotel. There-fore they ins t r u c t e d t h e i r a r c h i t e c t s to plan a b u i l d i n g that could be used for either purpose (7). The ar c h i t e c t s appar-ently saw nothing odd about t h i s - eithe r use requ i r i n g nothing more than c o r r i d o r s l i n e s with rooms plus s t a i r s , elevators and t o i l e t s . The b u i l d i n g ended up being an o f f i c e b u i l d i n g but a glance at the plan of a t y p i c a l f l o o r shows that a hotel would not be very d i f f e r e n t . In conclusion,,their assumption that the building could be eithe r a hotel or o f f i c e b u i l d i n g was succ e s s f u l . Following the rapid and extensive urbanization that took place af t e r the f i r s t World War, there was a corresponding expansion of big public o f f i c e s (Fig. 2.1 p. 9 ). But because of a kind ofinherent conservatism, even when the f i r s t b u i l d i n g s , predestined e x c l u s i v e l y for use as o f f i c e s , were put up, everybody continued to regard the o f f i c e as a hierarchy of r e s p o n s i b i l i t y rather than an integration of function. The opening out of the o f f i c e plan was, i n f a c t , dictated by a pressing and immediate economic necessity a f t e r the second World War - the need to accommodate more s t a f f i n the same space (8). Secretaries and c l e r k s were pooled but private o f f i c e s were given, to the administrators. In the f i r s t open plan o f f i c e there remained a number of status symbols. It was quite obvious that there was s t i l l a great prestige gap 9 4 134 H-V. § . 3 i 1 0 0 2 > Si - S 3 : I i i i i I JL «=iL «=£= 1 r T' ~r nr " j j 5 3 d CO 0. I >-y-3 • i i w A .GENERAL LOOK AT OLD. AND NEW TYPES OF OFFICE BUILDING F J G _ 2 J 10 between someone who worked i n one of the big communal open spaces and someone who had his own private o f f i c e . In the years between the wars, the development of the open plan o f f i c e was hindered by the l e i s u r e l y progress of technology, quite i n s u f f i c i e n t a i r conditioning, sound proofing and l i g h t i n g . The a r c h i t e c t facing an ever-increasing demand for open plan o f f i c e buildings w i l l f i n d an equally increased number of reasons to be concerned about the o v e r a l l acoustical performance of his work. The following are the main contributing factors to the a r c h i t e c t ' s a c o u s t i c a l problems: The number of e x i s t i n g o f f i c e s are encountering unprecedent room-acoustical problems. These problems, the solutions to which necessitate a considerable amount of research, derive from the need for a large f l o o r space f o r f l e x i -b i l i t y and a d a p t a b i l i t y i n the employees r e l a t i o n s h i p . - In the s t u c t u r a l and constructional f i e l d in order to save space and cost thin and lightweight materials are off e r e d . A l l constructional elements lack the most important feature of an e f f i c i e n t sound-insulating enclosure. Buildings are becoming increasingly mechanized. Com-ponents of heating, v e n t i l a t i n g and a i r - c o n d i t i o n i n g systems contribute to the noise pattern of an open plan o f f i c e . Today the benefit of mechanical and e l e c t r o n i c o f f i c e equipment, sometimes linked to computer f a c i l i t i e s , speed up data processing. This makes i t possible f o r o f f i c e workers to process quantities of information never dreamed of by those 11 working just a f t e r the turn of the century (9). In contempor-ary open o f f i c e planning the separate o f f i c e i s replaced by the work s t a t i o n . A work st a t i o n contains the equipment and furnishings needed by one or more employees. In order to get a better idea of today's needs i n o f f i c e space and the expected speech privacy, we w i l l now r e l a t e functions to the size of work sta t i o n and f l o o r plan f o r modern business operations-(10). 2.2 ARCHITECTURAL SPACIAL AND SPEECH PRIVACY CRITERIA ANALYSIS 12 Space Inventory. We must look at those who have to work in the o f f i c e s and plan from-the inside to the outside according to the functions and needs of the i n d i v i d u a l who works in the o f f i c e . An e s s e n t i a l requirement of a space s p e c i f i c a t i o n i s to determine the work s t a t i o n category and necessary equipment layout. The analysis of the function for each i n d i v i d u a l or the integrated team w i l l determine the work st a t i o n category. For a general look at how i n d i v i d u a l work places are ranged see F i g . 2.2 p. 13. An analysis of the user a c t i v i t i e s , defined according to the needs and tasks of each s t a f f member w i l l determine the actual space of each work s t a t i o n . Because of the v a r i a b l e complexity of organizations, there can be no r i g i d solutions to these problems of e x p l o i t a t i o n of space. Consequently any judgment expressed on the v a l i d i t y of any example of o f f i c e planning must always be r e l a t i v e to the p a r t i c u l a r s i t u a t i o n on hand. The r e l a t i v e work status of i n d i v i d u a l s , the number of i n d i v i d u a l work stations, the type and frequency of communication must be s a t i s f i e d before an o f f i c e space on the working f l o o r can be created. The o f f i c e design must f a c i l i t a t e multiple communications. There i s no doubt that an open space i s favourable to communications.while the i n d i v i d u a l o f f i c e i s h o s t i l e to i t . In open plan o f f i c e s , however, f u r n i t u r e has always been functional above everything e l s e . It must be able to house a l l 13 A RANGE TO SUIT MOST OPEN PLAN OFFICE TASKS From The Information Compiled by Shuttleworth, C , E.P.A., Working Paper, Snaepbrok, Lordswell Lane, Crowborough, Sussex, 1974. A. CLERICAL 40 s q . f t . B. CLERICAL 45 » C 1 CLERICAL - TYPING 40 " C 2 CLERICAL - TYPING 50 " D 1 CLERICAL - TYPING 45 " D 2 CLERICAL - TYPING 55 " E. TECHNICAL - PROFESSIONAL 75 11 F. DRAFTING 85 " G. PROFESSIONAL - TECHNICAL 100 " H. CLERICAL - PUBLIC INTERFACE 110 " J. SINGLE VISITOR - PRIVACY 125 " K. TECHNICAL - PROFESSIONAL - DRAFTING . . 125 " L. TWO VISITORS - PRIVACY 165 " M. SENIOR PERSONAL SECRETARY 185 » N. MANAGERIAL 190 " 0. DIRECTOR 250 " P. ASSOCIATE/ASSISTANT DEPUTY 350 " Q. DEPUTY MINISTER . . 450 " FIG. 2.2 14 the o f f i c e machines without any d i f f i c u l t y or waste of space. These things must a l l become an i n t e g r a l part of o f f i c e l i f e . The psychological and functional store of o f f i c e work and o f f i c e l i f e i s a complex of f i t t i n g s , f u r n i t u r e , machines, panels, stands, equipment, i n which, and with which the d a i l y work of the o f f i c e i s c a r r i e d out. This i s an assertion that any consensus of opinion w i l l e a s i l y v e r i f y . Space Evaluation. There are many d i f f e r e n t ways i n which people experience space, but we must set the standards to judge the v a l i d i t y of an i n d i v i d u a l ' s f e e l i n g of being cramped. The commonly accepted requirements for privacy on the part of o f f i c e workers and p a r t i c u l a r l y executives, are in f a c t greatly exaggerated (11) (12). Privacy achieved i s usually a cover for a desire for symbolic status. Privacy when act u a l l y required for c o n f i d e n t i a l interviews or meetings, can better be achieved through the provision of s p e c i a l spaces for the purpose rather than the b u i l d i n g of innumerable private cubicles (13) (14). Today we know that constructing an o f f i c e within a c e r t a i n area i s no longer a question of a l l o c a t i n g a c e r t a i n area per head, but according to the functions of the personnel concerned, i n d i v i d u a l s or groups. No two organizations have i d e n t i c a l work s t a t i o n layouts or space needs. The planners are concerned with the type of work c a r r i e d out i n c e r t a i n places as well as with the number and frequency of contacts and r e l a t i o n s h i p s with other groups and i n d i v i d u a l s that each job e n t a i l s . . For d i f f e r e n t choices of optimum siz e and shape within o f f i c e f l o o r see Figs. 2.3 to 2.6 pp. 15 to 16. It i s generally 15 645" V7Tu } v A u c o u v e R R . / -TYPICAL. T-tooR. 44oo & « T . 1 1 — • — » — • — « -> -# v—»—i • 1 O f f " <=LC. 0 o < _ « S £ » ft • <• 1 ) /2<3-n.G,_2,3.a 2.4 1 16 42.H IOMG.SV.AX, &UR.NAE>Y 4 — - i -TXP'CAt- Tlooll , SiCO SOT l i l t A t t V I H - E _ ( / A U e o U V B R f c ^ . DIFFERENT CHOICES OF OPTIMUM SIZE AND SHAPE WITHIN EXISTING OFFICE PLANS FIG, 2.5 a 2.6 17 true that the smaller the f l o o r size (less than 5,000 sq.ft.) the more d i f f i c u l t i t i s to plan detailed layouts which are acceptable, without wasting space. The t y p i c a l layout f o r o f f i c e accommodation i s a slab building i n the form of a rec-tangle with a s i n g l e center c o r r i d o r . When there i s no center core, a length of between 100 to 200 feet i s necessary, to provide 5,000 to 10,000 s q . f t . per f l o o r . Such a rectangular area c a l l s f o r very special care to overcome acoustical pro-blems, to minimize the long tunnel e f f e c t of the space, very large f l o o r s of open plan layout become impersonal. Provision for privacy of speech within open plan space i s the most important consideration. Therefore the physical and ac o u s t i c a l parameters, that e f f e c t speech privacy and the q u a l i t y of i n t r u s i v e noise produced by business machines, are to be considered i n achieving acoustical design goals. The O f f i c e Worker and Speech Privacy. The need f o r ease of communication, privacy and freedom from annoyance determine the acoustic requirements f o r an o f f i c e . In an o f f i c e the acoustic issue i s threefold: (a) An i n d i v i d u a l must not be unduly disturbed by the conversations of his neighbours whether they are i n 'the same o f f i c e or i n a nearby o f f i c e , nor must he be disturbed by noise intruding from outside (e.g. due to t r a f f i c ) or by noise insi d e the o f f i c e (e.g. due to o f f i c e machinery). (b) Members of the s t a f f must be able to communicate with each other e a s i l y and r e a d i l y either across the desk or over the telephone. 18 (c) Some conversations w i l l be of a private nature and should not be overheard and understood. These three aspects, w i l l be dealt with separately and sub-sequently drawn together to show how acoustic treatments can be used to deal with a l l three issues simultaneously. Architects have always been interested i n knowing how u t i l i z a t i o n of a v a i l a b l e space may be made more e f f e c t i v e by proper design. Psychological comfort f a c t o r s must be taken care of by ensuring a pleasing work environment providing freedom from v i s u a l d i s t r a c t i o n , yet with s u f f i c i e n t v i s u a l stimulation to avoid monotony (15). The acoustical aspects of adequate speech privacy and freedom from annoyance due to intruding sounds have proved to be among the most important fac t o r s leading to the success of o f f i c e planning (16). To a psychophysicist, the eye and the ear are s t r i k i n g l y s i m i l a r in t h e i r reactions to stimulation (17). Man's sense of space i s a synthesis of many sensory inputs. A worker's tolerance for crowding and methods for r e l i e v i n g f e e l i n g s of being crowded varies with the degree to which he i s sensorally involved with others (18). The problem of acoustical privacy has by no means yet been solved s a t i s f a c t o r i l y (19). Various attempts have been made to c o r r e l a t e objective measures of noise with i t s subjective e f f e c t on some sort of "annoyance" and i t s e f f e c t on speech privacy (20) (21). The r e s u l t s obtained are usually only applicable f o r that p a r t i c u l a r type of noise i n that p a r t i c u l a r environment. Studies i n d i c a t e that speech privacy i s in f a c t greater i n areas of a c o n s i s t e n t l y high l e v e l of noise than i t i s i n moderately quiet o f f i c e environments. 19 Design of Of f i c e s for Speech. Today o f f i c e s with t h e i r a c o u s t i c a l requirements create a problem of major importance i n achieving s a t i s f a c t o r y a c o u s t i c a l privacy between work stations in open plan o f f i c e s ( 2 2 ) ( 2 3 ) . When planning for the optimum ac o u s t i c a l conditions within an o f f i c e environment we must consider the c r i t e r i a which can provide the required privacy at any given p o s i t i o n ( 2 4 ) ( 2 5 ) . For rat i n g of an o f f i c e see F i g . 2 . 8 p. 2 1 . As shown i n t h i s figure, the o f f i c e with an SIL of about 30 dB w i l l be considered "quiet" by the occupants. For those o f f i c e s where the speech communication i s not so important, the ratings of F i g . 2 . 9 p. 21 apply. Both figures 2 . 8 and 2 . 9 show the e f f e c t of telephoning on noise l e v e l . These c r i t e r i a apply to intruding noises and to noises made i n the o f f i c e s themselves. The c r i t e r i a also applies to steady noises. In the absence of a s e n s i t i v e and objective procedure to supplement a r t i c u l a t i o n t e s t s , many inves t i g a t o r s have turned to subjective s c a l i n g methods fo r rating and paired comparisons to evaluate high q u a l i t y speech samples ( 2 6 ) . There i s an attempt to determine speech privacy require-ments ( 2 7 ) ( 2 8 ) . One of the important goals of the a r c h i t e c t and consultant i s to obtain adequate speech privacy i n modern buildings ( 2 9 ) . Several fac t o r s other than the transmission loss influencing speech privacy are to be taken into considera-t i o n while developing a r a t i n g method ( 3 0 ) . (See F i g s . 2 . 1 0 to 2 . 1 3 p . . 22 and Table 2 . 1 p. 2 4 . ) 20 NOISE CRITERIA (NC) CURVES FOR DETERMINING THE ACCEPTABLE OR DESIRABLE BACKGROUND NOISE LEVELS•IN ROOMS (These curves are recommended for s p e c i f i c a t i o n s wherever a favorable r e l a t i o n between the low frequency and the high frequency portion of the spectrum i s desired.) 1 5 0 3 0 0 FREQUENCY BAND 6 0 0 1 2 0 0 1 2 0 0 2 4 0 0 4 8 0 0 2 4 0 0 4 8 0 0 9600, FIG. 2.7 21 TWO CRITERIA FOR NOISE LEVELS IN OFFICES These c r i t e r i a made i n the o f t h a t i n t e r n a l be under t h e c t y p e w r i t e r s p r ped w h i l e a me These c r i t e r i a F o r l a r g e , ope speech communi F i g . 2.8 a p p l y shown a t th e t a p p l y b o t h t o i n t r u d i n g n o i s e s and t o n o i s e s i c e s t h e m s e l v e s . I t s h o u l d be n o t e d , however, n o i s e s may not be so c r i t i c a l b ecause t h e y may o n t r o l o f the o f f i c e p e r s o n n e l . F o r example, oduce an S I L o f 50 t o 80 dB b u t they can be stop-e t i n g o r a t e l e p h o n e c o n v e r s a t i o n i s i n p r o g r e s s . a p p l y t o s t e a d y n o i s e s . n o f f i c e s , such as t y p i n g p o o l s , where n o i s e and c a t i o n a r e not so i m p o r t a n t , t h e r a t i n g s o f The e f f e c t o f t h e n o i s e on t e l e p h o n i n g i s op o f bot h F i g s . 2.8 and 2.9. INTOLERABLY NOISY V E R Y NOISY 2 NOISY cc «2 MODERATELY O NOISY F i g . 2.8 R a t i n g o f O f f i c e s , P r i v a t e QUIET V E R Y QUIET 3 0 SPEECH INTERFERENCE LEVEL RANGES FOR TELEPHONE USE: SATISFACTORY SLIGHTLY DIFFICULT DIFFICULT UNSATISFACTORY SUMMARY GRAPH •A y $y ' DIRECTION OF DECREASED ACCEPTABILITY OF LL RELATIVE. TO SIL 4 _> y-FAVORABLE ACOUSTICAL ENVIRONMENT FOR EXECUTIVE OFFICES y / <0 5 0 6 0 70 6 0 9 0 S I L IN O E C I B E L S OR L O U D N E S S L E V E L IN P H O N S K>0 F i g . 2.9 R a t i n g o f O f f i c e s , C l e r i c a l and T y p i n g INTOLERABLY NOISY V E R Y NOISY o z £ NOISY CC — MODERATELY O NOISY QUIET V E R Y QUIET SPEECH INTERFERENCE LEVEL RANGES FOR TELEPHONE USE •• FAVORABLE ACOUSTICAL ENVIRONMENT FOR STENOGRAPHIC AND LARGE ENGINEERING 0RAFTING OFFICES OIRECTION OF OECREASED ACCEPTABILITY OF LL RELATIVE TO SIL 30 40 SO 6 0 70 6 0 9 0 S I L IN DECIBELS OR LOUDNESS L E V E L IN PHONS 100 2 2 OBSERVED REACTION TO PRIVACY t X T R E » C 0153 ATIS F A C T ION S T R O H C D I S S A T I S F A C T I O N M O D E R A T E OISSATISFACTION M I L O O l S S A T I S F A C T I O N A P P A R E N T S A T I S F A C T I O N CO •a • vHriT(veofr<cs O OC'wiTOftiCS 0 tO't lS * • • • ao O , 5.8 0 • 1 1 • •9 • 0 30 «0 AVE" AC t TL-01 K / / - T Y P I C A L L E V E L S ' IN A G E N E R A L O F F I C E A R E A V i • •••• KAHGC OF W E A S U R E O j L E V E L S IN T Y P I C A L / PR IVATT O F F I C E S / V 1 • • 1 'xisi-i:.:: . . : : . . : : : -V: : : - : - : - : : K E V E N I N G L E V E L S . - ' H O T E L B E D R O O M "V. : ; . : . : . : . : . :> « / ' r a 1 0 >i rmautxcr ma - C . C L C J « » stcoxo FIG. 2.IO P l o t of the subjective reactions observed in 37 cart "histories of speech privacy versus theavcrage T L rating of isolating wall. For the most part, published average T L value-were used; where the wall was llanked by other sound-transniiss-J11 paths, measured values were used. FIG. 2.11 Steady background-noise levels measured in spaces where speech privacy is important. The dashed-lines represent measurements in 62 private offices in which there was no com-plaint about the noise (reference 8) . Octave-band levels in the given percent of offices exceeded the dashed contour shown. S 90] I' m l to t o t i a zoo xn too t o o USQ IOOO aoo 3000 « o o o i .jcfl C I -OO WO t » *00 t M I COO itOO J.5O0 *OCO IMO lOOOO fMlftO OCTAVE BAKQ CEHTEft FREQUENCY IN CTd.CS PER 1 ECO NO Fic. 2 ) 2 Graphical representation of normal speech levels in a 100 sabine room. Number of dots in each third-octave band signifies relative contribution to articulation index. The data are obtained from Fig. 2 of reference 22 using the directivity-index data given by Beranek (reference 21) after H . K . Dunn and D. W. Famsworth L7- Acoust. Soc. Am. 10, 184 (1939)]. The peak factor o f speech is taken to be +12 db at all frequencies. O.J 0.4 0.3 o« or A R T I C U L A T I O N I N D E X Fic 2.13. Approximate relationship between articulation ircte and intelligibility for skilled talkers and listeners: The numbered parentheses give the size of the test vocabulary. S O M E C A S E H I S T O R I E S Figure 2 . 1 0 shows, that the ca t e g o r i z a t i o n scheme does not permit an accurate design f o r speech privacy. A more comprehensive r a t i n g scheme should be developed i n terms of which the case h i s t o r y data are reanalyzed. There are several f a c t o r s along with an estimated range, i n decibels, of t h e i r possible influence on speech privacy. (Background noise, published TL Data, s i z e , shape and sound absorption of the rooms to be i s o l a t e d , expected speech a c t i v i t y , kind of privacy required). continued 23 Some Case H i s t o r i e s continued The speech privacy i s related to speech i n t e l l i g i b i l i t y (which i s determined by the r a t i o of speech to noise). The above experimental work had looked for confirmation of t h i s assumed r e l a t i o n s h i p . It was found that each subject had a precise personal c r i t e r i o n for the speech-to-noise r a t i o which for him just constituted privacy, but that the assumed r e l a t i o n s h i p of i n t e l l i g i b i l i t y and privacy seemed to be consistent with the experimental r e s u l t s . In F i g . 2.12 the number of dots s i g n i f i e s r e l a t i v e contribu-t i o n to a r t i c u l a t i o n index. The objective quantity has been em p i r i c a l l y r e l a t e d to the i n t e l l i g i b i l i t y of various kinds of speech (as unrelated words and sentences) as shown i n F i g . 2.13. The study t r i e s to determine i f t h i s same quantity could also be r e l a t e d to the f e e l i n g of speech privacy. FIGS. 2.10 to 2.13 24 • SUGGESTED CRITERIA FOR. NOISE CONTROL Table 2.1 Speech-interference levels (in db re 0.0002 microbar) should be less than the values given below in order to have reliable conversation at the distances and voice levels shown. Voice Level ' Distance Very (Feet). Normal Raised, Loud Shouting 0.5 71 77 83 89 1 65 71 77 83 2 59 65 '- 71 ' 77 •• 3 55 61 • 6 7 73 4 • • :': 53 59 65 71 5 51 . ' 57- 63 69 6 : ••: 49 55 61 • 67 12 '• 43 • .: : 49 55 61 24 37 43 • 49 55 SPEECH INTELLIGIBILITY. For satisfactory intelligi-bility of difficult speech material, maximum permissible values of speech-interference levels for men with average voice ; strengths are given \ -\ Table 2.2 Suggested criteria for noise control in terms oi maximum permissible speech-interference level (SIL), measured when the room is not in use, are given in the following table: . Maximum Permissible SIL Type of Room (measured when room is not in use) Small Private Office 40 Conference Room for 20 30 Conference Room for 50 25 Movie Theatre 30 Theatres for Drama (500 seats, no amplification) 25 Coliseum for Sports Only (Amplification) 50 Concert Halls (No amplification) 20 Secretarial Offices (Typing) 55 Homes (Sleeping Areas) 25 Assembly Halls (No amplification) 25 School Rooms 25 25 In conclusion, speech privacy may be viewed as e i t h e r conditions in which speech i s not overheard or in which speech i s merely not understood (31). Not only must the acoustic design ensure that the appropriate condition exists but.also that the i n d i v i d u a l concerned i s convinced that this i s so. C l e a r l y , i f someone i s able to understand conversations emanating from nearby o f f i c e s he w i l l not believe that his conversations are p r i v a t e . S i m i l a r l y , though adequate back-ground noise may i n fact provide conditions of speech privacy, an i n d i v i d u a l who i s v i s i b l e to co-workers i n an open plan o f f i c e may f e e l his conversation i s being heard. Therefore, in the design of an open plan o f f i c e a key consideration for a c o u s t i c a l e f f i c i e n c y i s a d e l i c a t e balance between aco u s t i c a l privacy and speech c l a r i t y . There are many publications on the open plan o f f i c e , but l i t t l e information i s c o l l e c t i v e l y a v a i l a b l e on techniques for good acoustical planning (32). The problem does not require a t o t a l l y new technology, but rather an i n t e l l i g e n t a p p l i c a t i o n of e x i s t i n g properly i n s t a l l e d systems and the appropriate use of a v a i l a b l e products. 26 2.3 ACOUSTICAL PERFORMANCE OF SPECIFIC BUILDING ELEMENTS In a l l open o f f i c e f l o o r plans having requirements for speech privacy, the a c o u s t i c a l objective must be to achieve minimum speech i n t e l l i g i b i l i t y for communications that are not to be overheard. Once speech a c t i v i t y i s determined and suf-f i c i e n t c r i t e r i a f o r p r e d i c t i n g a c c e p t a b i l i t y i s established, the choice of optimum size and shape within the o f f i c e f l o o r plan and the other factors i n f l u e n c i n g room surfaces are equally important. To insure the elimination of disturbing noise i n order to provide necessary speech privacy, the following means are commonly used: (1) E f f i c i e n c y sound absorptive materials on the f l o o r , c e i l i n g and walls. (2) A c o u s t i c a l l y e f f i c i e n t screens between work s t a t i o n s . (3) Introduction of a uniform background sound. C e i l i n g and Floors. The c e i l i n g and f l o o r may be con-sidered mirrors, which r e f l e c t multiple images of the source, as seen by the r e c e i v e r . These images are reduced at each r e f l e c t i o n i n strength by distance, by the cumulative absorp-ti o n c o e f f i c i e n t s of the f l o o r and c e i l i n g , and by the presence of a screen b a r r i e r between the source and r e c e i v e r . Further to Geiger and Hamme findings, s i g n a l strength i s much more dependent on absorption c o e f f i c i e n t than i t i s on c e i l i n g height. There are v a r i a t i o n s of absorption c o e f f i c i e n t with angle of incidence. A graph -which demonstrates this e f f e c t i s produced by Geiger and Hamme (see F i g . 2.14 p. 27). 27 •SOUND A B S O R P T I O N C O E F F I C I E N T Graph i l l u s t r a t i n g dependence of absorption on nngle of i n c i d e n c e (from G e i g e r & Hamme). .. FIG. 2.14 28 For published values of the absorption c o e f f i c i e n t of c e i l i n g materials, which are generally based on a reverberation room test and include an average of r e l f e c t i o n s at a l l angles, see Table 2.3 p. 29. Measurements conducted by Geiger and Hamme have demonstrated that the thicker f i b e r g l a s s products have an absorption c o e f f i c i e n t at 40 to 50 degrees (33) s i m i l a r to the average absorption measured i n a reverberating room. Carpeting on f l o o r s also are e f f e c t i v e sound absorbants. The prime value of carpeting i s to reduce scraping and impact sounds from f o o t f a l l and moving chairs, e t c . Walls, Drapes and Windows. Windov/s should be covered with f u l l pleated f i b e r g l a s s draperies or angled out at the top to r e f l e c t sounds back at the c e i l i n g . Sound absorption of drapes i s very important i n the con-s i d e r a t i o n of noise reduction. Measurements of the a c o u s t i c a l absorption are introduced by various configurations of drapes into a small reverberating room. Findings are presented by James H. Batchelder and William S. Thayer (34). This study further states that a single layer of heavy material hung un-draped at the center i s most e f f i c i e n t . The'noise reduction of a sound patch involving the r e f l e c -t i o n from wall/windows i s comparable to f l o o r / c e i l i n g consider-ati o n s . Furthermore, the cumulative absorption c o e f f i c i e n t s of wall f i n i s h i n g and window treatment i s s i m i l a r to the absorp-t i o n q u a l i t i e s , b a r r i e r between the source and r e c e i v e r . For the average values of the absorption c o e f f i c i e n t s of wall f i n i s h i n g , glass openings and curtains, see Table 2.3'p. 27. 29 SOUND ABSORPTION COEFFICIENT FOR: A l p h a b e t i c a l l y L i s t e d M a t e r i a l s L i s t e d According to Their Surface F i n i s h e s ( c o e f f i c i e n t s are f o r one square f o o t ) . (From the Information Compiled by J.E. Moore, FRIBA; Design f o r Noise Reduction, A r c h i t e c t u r a l Press, London, 1966). c/s: 125 250 500 1000 2000 4000 AIR per cubic foot: — — — 0001 0 002 0-006 ASBESTOS FIBRE \" sprayed on solid backicg: 0-10 0-15 0-40 0-70 0-80 — ASBESTOS naR£ V sprayed on solid backing: 0-15 0-40 0-75 0-90 0-90 — AUDIENCE per person, in wood, padded, or metal and canvas chairs: 1-7 3-8 4-3 4-3 4-7 4f AUDIENCE per person, in wcti-upholstcrcd » j 'scats: 2 0 4-3 5-0 5-0 5-5 50 AUDIENCE per square foot of 'auaience area' including gangways not more than 3' 6" wide: 0-52 0-68 0-85 0-97 0-93 0-85 BRICKWORK unpaintcd: 0 02 0 02 003 004 0-04 005 BRICKWORK painted: 001 001 002 002 002 002 CARPET light, on thin felt, on concrete floor: 0-10 0-15 0-25 0-30 0-30 0-30 CARPET light, o:i boarded floor with air space: 0 20 0-25 0-30 0-30 0-30 0-30 CARPET heavy, on thick fci.', on concrete floor: 010 0-25 0-50 0-50 0-60 0-65 CHAIRS sec under 'seating* CONKER DLOCKS unplas'.cred: 0-20 0-30 0-60 0-60 0-50 0-50 continued TABLE 2.3 30 COEFFICIENTS OP SOUND ABSORPTION continued c/s: CONCRETE smooth, dense finish: 125 001 250 001 500 0-02 1000 0-02 2000 0-02 4000 0 03 CONCRETE rough, porous finish: 001 0 02 002 004 005 005 CORK TILES bedded solid: 002 0-04 0 05 005 0-10 005 CURTAINS medium weight, hung in folds against solid backing: 0-10 0-40 _ 0-50" 0-60 CURTAINS double or lined, dividing two spaces: 003 0-04 0-10 0-15 0-20 0-15 FIBREBOARD soft, Yt wood or cane fibre, solid mounting, unpainted: 0 05 0-10 0-15 0-25 0-30 0-30 FIBREBOARD ditto, painted: C-05 0-10 1 fi-in • . 0-!0 n.to n.t«: FIR8EBOARD soft, \ ' , wood or car.e fibre, oa battens, 1* air space, unpainicd: 0-30 • 0-35 0-30 FIBREBOARD ditto, painted: 0-30 — 015 — 0-10 FJBREBOARD TILES soft wood fibre, £* perforated, on battens, 1" air space: 0-20 0-50 0-70 0-85 0-75 0-75 FIBREBOARD TILES soft wood fibre, 1", slotted, on battens, 1' air space: 015 0-65 0-75 100 0-95 0-70 FIBREBOARD TILES soft wood fibre, J " , grooved, or. battens, 1" air space: 0-15 0-40 0-55 0-70 0-SO 0-70 CLASS in windows, up to 32oz: 0-30 — 0-10 — , 0-07 CLASS in windows, £ ' plate: 010 — 005 0-02 _ GLASS bedded solid: 001 — 001 002 „ CRANOLITHIC on solid floor: 001 — 002 0 02 IIAROBOARD on battens, 1" air space: 0-20 — 015 — 010 — continued ~~ TABLE 2.3 COEFFICIENTS OF SOUND ABSORPTION COntin'. c/s: 125 250 500 toco : zcco * iOOO HARDBOARD . . 1 0 % perforatca, i ' -fiorcgiaas in air space: 0-15 0-30 0-75 0-S5 0-75 0-40 HA:- ^ OARD TILES perforated, on grooved wood fibrcboard, on battens, 1* air " space: 0-21 — 0-66 — 0-80 — HARDBOARD TILES perforated, on J perforated wood fibreboard, on battens, 1* air space: 0-30 — 0-40 — 0-50 LINOLEUM1 on solid floor: 002 004 0 05 005 0-10 0-05 MARBLE on solid backing: 001 . — 001 — 0-02 — METAL TILES „..r_ r n .~H r«ecl travs. I rocx-v.-oolpads, suspended below air space: 0-10 i 0-30 0-65 0-75 - „, i u-ci METAL TILES as above but 2' rockwool: 0-25 0-75 0-S5 0-S5 0-75 0-50 METAL TILLS . . perforated aluminium dcub.e panels, i * glasswool filling, suspended below air space: 0-32 0-52 0-90 0-95 0-81 — MINERAL TWRE TILES rigid mineral fibre lues, mounted solid: 003 0-31 0-82 0-33 0-75 0-76 MINERAL FIBRE TILES as above but suspended below air space: 0-61 0-72. 0-76 0-71 0-81 0-79 OPENINGS F open windows, per sq ft ot opening: 1-0 1-0 10 1 0 1 0 * 10 OPENINGS . ventilation grilles, 50/„ voids. 015 — 0-35 — 0-30 — PEOPLE see under 'audience PLASTER lime or gypsum on solid oac.ang : 003 003 0 02 0-03 004 005 PLASTER . . lime or gyP^m on joists or .studs: 00] 0 1 ! > O K ) 0 0! 0-04 005 ' continued TABLE 32 COEFFICIENTS OF SOUND ABSORPTION continued c/s: PLASTER suspended ceiling with large air 3po.ee: 125 250 500 0-10 1000 0-04 2 X 0 004 4000 PLASTER TILES perfr-r 'cd, fibre plaster, alumJLL-m foil backing, free air space: 0-45 0-70 0-80 0-SO 0-65 0-45 PLASTER TILES perforated, i' gypsum, fibre glass tissue backing, 1* airspace: 0-20 0-65 0-35 PLASTER TILES perforated, J ' gypsum, 1" fibre glass quilt, 1" air space: 0-30 0-SO _ 0-45 POLYSTYRENE TILES i * expanded polystyrene, un-pcrforatcd, 1* air space: 0-05 0-40 0-20 POLYSTYRENE TILES i' expanded polystyrene, per-forated, 1' air space: 0 05~ 1 0-70 0-20 _ i RUDDER flooring on solid floor: 002 004 005 005 0-10 0 05 SEATING wood, padded or metal and canvas, per seat: 0-80 _ 1-60 1-90 2-10 SEATING well-upholstered, fabric-covered, • per seat: 1-30 _ 300 3-40 4-00 SEATING per sq ft of 'seating area* in-cluding gangways not more than 3'6* wide, well upholstered, fabric-covered, perforated un-derside: 0-44 0-60 0-77 0-S9 0-S2 0-70 STEEL sec under 'metal'. STONE natural finish: 0 02 0 02 0 02 004 0 05 005 STONE polished: 001 0-01 001 0 02 002 003 TERRAZZO on walls cr floors: 001 001 001 002 002 0 03 TILES glazed: 001 001 001 002 0 02 003 continued TABLE 2.3 33 COEFFICIENTS OF SOUND ABSOKPTION continued c/s: TILES unglazcd: 125 002 250 0 0 2 500 0 02 1000 004 2000 0 05 4000 005 WATER as in swimming bath: 001 _ 001 — 0 0 2 — WINDOWS sec under 'glass' and 'openings' t WOOD BLOCKS on solid floor: 002 0 04 005 0 05 0-10 0 05 WOOD BOARDING J" over air space: 0-20 0-15 0-10 0-10 0-10 0-10 WOOD FLOORING 1" boarding on joists or battens: 0-15 0-20 010 0-10 0-10 0-10 WOOD PANELLING 3-ply on battens, 1* air space: 0-30 — ' 0-15 — 0'10 — WOOD PANELLING 3-ply on battens, 1* acoustic felt in air space: 0-40 0-15 0-10 --WOOD PANELLING 15% perforated, 3-ply, on battens, T fibre glass in air space: 0-20 0-60 0-35 WOOD-VF.NEERF.D TILES perforated, on perforated fibre-board, on battens, 1* air space: 0-20 0-50 0-75 • _ WOODWOOL SLABS 1", unplastered on solid backing: 0-10 — 0-40 — 0-60 — WOODWOOL SLABS 3", unplastered on solid backing: 0-20 — 0S0 — OSO — WOODWOOL SLABS 1", unplastered on battens, on solid wall, 1" air space: 0-10 — 0-60 — 0-60 — TABLE 2.3 34 Screen B a r r i e r s . There are a number of factors determing the l e v e l of a c c e p t a b i l i t y i n the open o f f i c e of acoustic screening. The attenuation of a sound b a r r i e r i s determined by edge d e f l e c t i o n over the b a r r i e r and by sound transmission through the b a r r i e r . The c a l c u l a t i o n of the excess attenua-t i o n due to the d e f l e c t i o n around a b a r r i e r of sound rays emanating from a point source i s represented i n a simple mathe-matical formula (35) (36). The attenuation value of b a r r i e r s has shov/n considerable v a r i a t i o n depending on the context a p p l i c a t i o n of the formula (37) (38). We may next consider some of the methods of introducing sound absorbing materials in t o a room and i n p a r t i c u l a r the best position for such elements. In o f f i c e s occupied by a number of people and with a c e r t a i n amount of sound-absorbing f u r n i t u r e , noise produced from typewriters w i l l to some extent be absorbed on the horizontal plane. I t becomes, therefore, more important to absorb sound t r a v e l l i n g upwards. The c e i l i n g and upper part of wall surfaces are, then, the more e f f e c t i v e areas for treatment. The acoustic absorbants need not necessarily be applied "on the f l a t " . Total absorption can be increased by modelling the a v a i l a b l e surface or special sound-absorbing units can be suspended from the c e i l i n g . Some of these arrangements are shown i n F i g . 2V. 15 p. 35. The above techniques have been used to test a v a r i e t y of c e i l i n g materials and configurations. According to i n v e s t i g a -tions conducted by Geiger and Hamme Laboratories"(39), i t i s possible to determine the e f f e c t of varying screen dimensions, c e i l i n g l i g h t i n g f i x t u r e s and horizontal r e f l e c t i o n s from 35 SOME OF THE ARRANGEMENTS THAT CAN BE ACHIEVED BY RE-MODELLING THE AVAILABLE SURFACE OR ADDING SPECIAL SOUND ABSORBING MATERIALS II 1 1 M 1 1 t I S O U N D - A D S O R B I N G L O U V R E S M O D E L L E D A B S O R B E N T S U R F A C E LAYLIGHT " E G G C R A T E -A B S O R B E N T B O T H S I O E S FIG. 2.15 36 o f f i c e f u r n i t u r e and other t y p i c a l aspects of open plan o f f i c e s . Masking Sound System. In many s i t u a t i o n s noise-control problems can be solved by masking unwanted noises by e l e c t r o n i -c a l l y created background noise. If a masking system i s unin-terrupted and i s not too loud, and i f i t has no information content, i t w i l l become an acceptable background noise and w i l l suppress other objectionable intruding noises. V e n t i l a t i n g and a i r - c o n d i t i o n i n g noises are good masking noise sources. In designing open plan o f f i c e s the provision of a r e l a t i v e l y high but acceptable degree of background noise.is e s s e n t i a l in order to mask undesirable o f f i c e noises created by typewriters, telephones, o f f i c e machines or loud conversation and to provide a reasonable amount of privacy. The recommended maximum per-missible background noise l e v e l s in various occupancies can be s p e c i f i e d i n terms of noise c r i t e r i a (NC) curves i l l u s t r a t e d i n F i g . 2.7 p. 20, Table 2.2 p. 24 shows the permissible background noise l e v e l s i n various occupancies. It appears that in the se l e c t i o n of an appropriate NC curve or any other suitable c r i t e r i a f or noise control in o f f i c e s , the a r c h i t e c t w i l l have to make a judicious decision because of the wide range of functions and sizes of o f f i c e spaces and i n d i v i d u a l differences i n noise tolerance. 37 2.4 GENERAL ACOUSTICAL GUIDELINES The acoustical performance of s p e c i f i c building elements in selected combinations can provide excellent acoustical performance. In open plan o f f i c e there are three v i t a l con-siderations to be borne i n mind: 1) privacy of speech, 2) reverberant sound energy, and 3) masking sound l e v e l s (40). The a c o u s t i c a l design c r i t e r i a f or any project i s based on a set of guidelines, established for acceptable sound con-t r o l , then adapted to the s p e c i f i c conditions of a p a r t i c u l a r project (41). A group of aco u s t i c a l designers has evaluated and modified the guide to render i t a valuable tool f o r other designers (42). The e x i s t i n g design guidelines presented herein w i l l be useful to persons concerned with general ac o u s t i c a l g u i d e l i n e s . Recommended Design Guidelines (1) Guidelines for speech privacy conditions at any point in an open plan o f f i c e are stated i n the Canadian Building Digest, Report NRC - CBD 139, (July 1, 1971 by L.W. Hegwold). (2) Another design provision i s outlined by J.E. Sulewsky, "Acoustical Design Guidelines f o r O f f i c e Landscaping - Sound & Vi b r a t i o n " , (June, 1971). The guideline provides necessary speech privacy by eliminating the disturbing noise and the sound r e f l e c t i o n and by providing background masking sound produced e l e c t r o n i c a l l y in order to cancel word information. The minimum design provisions include the use of highly absorp-t i v e acoustical systems: carpeting and absorptive treatment on the walls. In addition, the spectrum of the tuning system i s 38 determined to provide adequate masking of word i n t e l l i g i b i l i t y at design distances without sounding "noisy". This guide r e l i e s mostly on experience. (3) In t h i s design guideline outlined by J.H. Sabine, "Acoustics of Open Plan O f f i c e s - Sound & V i b r a t i o n " , (September, 1973), the author describes the Test Methods and S p e c i f i c a t i o n s prepared by Geiger & Hamme Inc. These are based on t h e i r extensive consulting work and laboratory and f i e l d t e s t i n g for open plan o f f i c e p rojects. His findings seem to y i e l d the mostpractical solutions to the problem. The sum of main factors and requirements involved i n open o f f i c e speech privacy i s set down. It includes the Test Method for the Direct Measurement of Speech Privacy P o t e n t i a l Based on Sub-j e c t i v e Judgments, so c a l l e d PBS - C . l and Objective Test PBS -C.2 as an a l t e r n a t e . This test w i l l be used as the guideline for speech privacy conditions i n the survey under study. For the interzone attenuation i n governing speech privacy, see F i g s . 2.16 and 2.17 p. 39. Generally a l l guidelines prescribe a s i m i l a r procedure: (1) Find a v a i l a b l e data i n order to r e a l i z e the i n t e r n a l noise problem. (2) Sample the necessary data on noise tolerances for d i f f e r e n t a c t i v i t i e s and noise l e v e l s of t y p i c a l sources to which c e r t a i n graphs r e f e r . (3) Refer to a guide how to reduce the noise l e v e l s by the use of absorption, screen b a r r i e r s or masking noise. 3 9 THE OPEN SKY & GYPSUM BOARD CEILING TESTS PERFORMED BY GEIGER & HAMME . ( A s p r e s u m e d t o p r e s e n t t h e a t t e n u a t i o n l i m i t s o f c h a m b e r c h a r a c t e r i z a t i o n s . ) Open S k y VJ1TM SC-BiZtU^ r tr D i s t a n c e F r o m S o u r c e (Feet) com -G y p s u m B o a r d < c 1 I -tr D i s t a n c e F r o m S o u r c e (Feet) The left hand part of FIGURE illustrates the lest setup used in Geiger & Hamme's deter-mination of open sky screen shadowing po-tential. A 5-by-15-foot screen, with acousti-cally absorptive surfaces, was erected on the 1 laboratory roof and a sound source positioned 6 feet from the screen and 4 feet from the ; floor. Sound level readings were taken at the i same height on both sides of the screen. A j reference reading was taken 3 feet from the ; sound source, and the difference between this ! reference sound level and the reading taken • on the other side of the screen at 3-foot in-tervals was defined as the attenuation at each measuring point. The attenuation, averaged from 500 to 2000 Hz, ranged from 25 dB 3 feet beyond the screen to 27 dB 15 feet beyond (9 to 21 (eet from the sound source). ' Tho mean attenuation behind the screen, or its "screen shadowing potential," is repre-: sented by a shaded area on the curve above, i left. The right hand pan of FIGURE .'• above illus-trates the lest setup in the Geiijsr 8. Hamme laboratory which duplicated the open sky roof-top setup. An open office mockup 15 by 30 feet, with an 8'-10" ceiling beneath a 32" plenum, was divided by a 5-by-15-foot screen, as on the roof. The floor was carpeted, and the walls were acoustically treated to min-imize sound reflection. Sound source location and attenuation measurements were the same as for open-sky measurements. The arrange-ments simulated ihe effect in an open office. Above the ceiling, speakers were mounted in the plenum facing upwards against a reflec-tive slab, to provide controlled electronic masking sound for subjective listening tests. The first ceiling tested, of gypsum board, pro-vided interzone attenuation of only 10 dB (as compared to 25 dB attenuation under open sky testing). Subsequent tests with different types of ceiling structures were run in this labora-tory environment, and subjective listening tests used to establish correlation between instrument readings and tho human ear, as mentioned. Fl G. 2.I6 40 THE OPEN SKY & GYPSUM BOARD CEILING TESTS PERFORMED BY GEIGER .& HAMME ( F i g . 2.17 p l o t s t h e a t t e n u a t i o n w i t h r e s p e c t t o t h e " b e s t " and " w o r s t " c o n d i t i o n s i n . t h e f i r s t t e s t s - see F i g . 2.16. These r e f e r e n c e s a r e shown i n F i g s . 3.30 t o 3.34, where a t t e n u a t i o n i s p l o t t e d a g a i n s t t h e d i s t a n c e f r o m t h e sound s o u r c e b e h i n d t h e t e s t e d sound s c r e e n . ) X S ui o z o •o z o a z Ui z < s 50 45 40 35 45 *** 1* 1* CCICIKIC 9' 12' 15' 18' DISTANCE FROM SOURCE (FEET) NOTE OPEN SKY CEILING - p l o t s t h e a t t e n u a t i o n w i t h r e s p e c t t o t h e " b e s t " c o n d i t i o n s . TARGET CE I L I N G - p e r f o r m a n c e o f t h e 2" f i b e r g l a s s TL - backe d Nubby g l a s s c l o t h i n c o n j u n c t i o n w i t h t h e sound s c r e e n s i n d i c a t e d good a t t e n u a t i o n p r o p e r t i e s . GYPSUM BOARD CEILING - p l o t s the a t t e n u a t i o n w i t h r e s p e c t t o t h e " w o r s t " c o n d i t i o n s . FIG. 2.I7 With the aid of the present requirements for organizational f l e x i b i l i t y optimize the d i f f e r e n t f a c t o r s to make the noise s i t u a t i o n acceptable. 42 2.5 REFERENCE 1. Scottsass, E. Jr, "UFFICI" (From the T r a d i t i o n a l  O f f i c e to the Open-Plan O f f i c e ) . Published by Direzione R e l a t i o n i C u l t u r a l i Desegno I n d u s t r i a l -P u b l i c i t a ' of O l i v e t t i , Milano, 1973. Cavanaugh, W.J. F a r r e l l , W.R. H i r t l e , P.W. Watters, B.G. Schroeder, M.R, Speech Privacy i n Buildings. The Journal of the Acoustical Society of America, Vol. 34, No. 4, A p r i l , 1962. Recent Studies in Speech Research at B e l l Telephone Laboratories ( I ) . ICA A21, Liege 7-14, Sept., 1965. Hirsh, I . J . The Third Annual Fairey Lecture: Acoustical Bases of Speech Percep-t i o n . Journal of Sound V i b r a t i o n 1973 27(1), 111-122. Keighley, E.C, M i l l e r , G.A. (1) The Determination of A c c e p t a b i l i t y  C r i t e r i a for O f f i c e Noise. J . Sound Vib. (1966) 4(1) 73-87. (2) A c c e p t a b i l i t y C r i t e r i a f o r Noise  in Large O f f i c e s . J~. Sound Vib. (1970) l l ( i ) , 83-93. Speech and Communication: The Journal of the Acoustical Society of America, V o l . 30, No. 5, May, 1958. Scottsass, E. J r . "UFFICI" (From the T r a d i t i o n a l .  O f f i c e to the Open-Plan O f f i c e ) . Published by Direzione R e l a t i o n i C u l t u r a l i Disegno I n d u s t r i a l -P u b l i c i t a ' of O l i v e t t i , Milano, 1973. Planas, R.E. 9. Cowan, P., Fine, D, Integrated Planning Concept  Imperative f o r O f f i c e Landscaping, Paper by President of Quikborner Team, Inc., Milburn, N.J. The O f f i c e , A Facet of Urban_ Ireland, J., Judon, C.,Growth. Heinmann Educational Mercer, D., Sears, A. Books Ltd., London, 1969. 43 10. Lindsay, R.B. 11. Cavanaugh, W.J. F a r r e l l , W.R. H i r t l e , P.W. Wat hers, B.C. 12. Clarke, F.R. The Story of Acoustics. The Journal of the Acoustical Society of America, V o l . 40, 1960. Speech Privacy i n Buildings. Journal of the Acoustical Society of America, V o l . 34, No. 4, A p r i l , 1962. Confidence Ratings, Second-Choice Responses and Confusion MatrTces**' i n I n t e l l i g i b i l i t y Tests. Journal of the Acoustical Society of America. V o l . 32, No. 1, January, 1960. 13. (U.S.) Environmental Protection Agency Fundamentals of Noise: Measure-ment, Rating Schemes, and Standards. Washington, D.C. 20460, Dec. 31, 1971. 14 Keighley, E.F. The Determination of A c c e p t a b i l i t y C r i t e r i a for O f f i c e Noise. of Sound and V i b r a t i o n . r ( l ) 73-87. Journal (1966) 15. Burris-Meyer, H, C a r d i n e l l , R.L. 16. Moreira, N.M. Bryan, M.E. Applied Psychoacoustics. ICA, H15, Copenhagen, 21-28, August, 1961. Noise Annoyance S u s c e p t i b i l i t y . Journal of Acoustical Society of America (1972) 21(4) 449-462. 17. Stevens, S.S. C a l c u l a t i n g the Perceived Level of  Light and Sound"! 1971 Rayleigh Gold Medal Address: Journal of Sound & V i b r a t i o n , 1972 23(3) 297-462. 18 20, Stevens, S.S. 19. Kryter, K.D, Lavjrence, M. Procedures for C a l c u l a t i n g Loudness: Mark VI Journal of Acoustical Society of America. Vol. 33, No. 11, November, 1961 pp. 1577-1585. The Meaning and Measurement of .Perceived Noise Level. Noise Control, Vol. 6, No. 5, September-October, 1960 pp. 12-27. Phys i o l o g i c a l and Psychological  Acoustics. Journal of the Acoustical Society of America, Vol. 30, No. 5, May, 1958. 44 21. Gibson, J . J . 22. Voiers, W.D. 23. Taylor, C. 24. Neely, R.B. Reddy, D.R. 25. Nakatani, L.H. 26. Carterette, E.C. Cole, M. 27. Black, J.W. 28. Deatherage, B.H. 29. Harris, J.D. 30. M i l l e r , G.A. 31. Masterton, B. Heffner, Henry Ravizza, Richard 32. Young, W.R. The Senses Considered as Perceptual Systems. Boston: Houghton M i f f l i n , Perceptual Bases of Speaker Identity. Journal of A c o u s t i c a l Society of r America, Vol. 36, No. 6, June, 1964. A r c h i t e c t u r a l Psychology: A Pion-eering Program, to be published i n the Consulting Engineer. Speech Recognition in the Presence  ot Noise. ICA, 2 3C14, Budapest, 1971. A Sensitive Test of Speech Communi-cation Quality Journal of the " Acoustical Society of America, Vo l . 53, 1973. Comparison of the Receiver -Operating C h a r a c t e r i s t i c s f o r Messages Received' by Ear and by Eye. Journal of Acoustical Society of America. V o l . 34, No. 2, February, 1962. Training for Voice Communication. Journal of the Acoustical Society of America, V o l . 18, No. 2, October, 1946. Auditory Sensation. Journal of the Acoustical Society"of America, Vo l . 42, No. 2, 1967. Pure-Tone Acuity and the I n t e l l i g i -b i l i t y of Everyday Speech. Journal 67 the Acoustical Society of America. Vol. 37, No. 5, May, 1965. Speech and Communication. Journal of the Acoustical Society of America, V o l . 30, No. 5, May, 1958. The Evolution of Human Hearing. Journal ot the Acoustical Society of America, Vol. 45, No. 4, 1969. Revision of Speech Privacy Calcu- l a t i o n . Journal of Acoustical Society of America, Vol. 37. 45 33. 34. Batchelder, J.H. Thayer, S.W. 35. Moreland, J.B. 36. Maekawa, F. 37. Kurze, U.J. & Anderson, G.S, 38. Lowe, A.W. 39. Geiger and Hamme 40. Pirn, R. 41. Hegvold, L.W. Fiberglass - Acoustical Manual. Sweet's Canadian Construction Catalogue F i l e , V o l . 4, 1974. Sound Absorption of Drapes: Journal of the Acoustical Society of America: V o l . 42, 1966. The Performance of Acoustic  B a r r i e r s from Inter-Noise 72 Proceedings. Noise Reduction by Screens Applied Acoustics (1), 1968. Sound Attenuation by B a r r i e r s : Applied Acoustics, C 4 l (1971) . The Effectiveness of Barriers Under  Extended C e i l i n g s . From Inter-Noise 72 Proceedings. a) Test Method PBS-C1 for the d i r e c t measurement of speech privacy poten-t i a l (SPP) based on objective judge-ment. U.S. General Service Admini-s t r a t i o n , August 19, 1972. b) Test Method PBS-C2 for the s u f f i c i e n t v e r i f i c a t i o n of speech privacy poten-t i a l based on objective measurements including methods of f u n c t i o n a l inter-zone attenuation and NC-background. c) Guide for Acoustical Performance S p e c i f i c a t i o n of an integrated c e i l i n g and background system. U.S. General Service Administration. August, 1972. Acoustical Variables in Open Planning, Journal of the Acoustical Society of America, 49, 1339, 1971. Acoustical Design of Open Planned O f f i c e s . Canadian Building Digest, NRC, DBR, CBD, 1397 Ottawa, July, 1971. 42. Powell, J.A. Harman, D.M. A Design Guide - Information Required  for the Acoustic Design of O f f i c e s : Applied Acoustics (2), (1969). 46 3. SURVEY OF THE NOISE CLIMATES IN OPEN PLAN OFFICES 3.1 DESCRIPTION OF OFFICES STUDIED 3.2 SUBJECTIVE TESTING AND OBJECTIVE MEASUREMENTS 3.2.1 Acoustical Considerations and Occupant Questionnaire 3.2.2 Measurement of the Acoustical C h a r a c t e r i s t i c s of the Offices 3.2.3 Results and Analysis of the Data 3.3 COMPARISON OF THE OFFICE SAMPLE STUDIES TO APPROVED ACOUSTIC GUIDELINES 3.3.1 Acceptable C r i t e r i a f or Noise in Large O f f i c e s (E.C. Keighley) 3.3.2 Test Method PBS-C.l and PBS-C.2 (U.S. Public Building Services) 3.3.3 S i m p l i f i e d A r t i c u l a t i o n Test (J.D. G r i f f i t h s ) 3.4 CONCLUSION OF THE.SURVEY 3.5 REFERENCE 47 3.1 DESCRIPTION OF OFFICES STUDIED This section presents an acoustical i n v e s t i g a t i o n of four company o f f i c e s with seven d i f f e r e n t f l o o r layouts a l l i n Vancouver, B.C., and discusses the general acoustical con-siderations of these o f f i c e samples. The writer t r i e s to c o r r e l a t e these e x i s t i n g s i t u a t i o n s with the theories discussed in the previous section. Human response to noise i s influenced by various q u a l i t i e s of the noise i t s e l f , by the i n d i v i d u a l c h a r a c t e r i s t i c s of the respondent and by other amenities of the o f f i c e . The purpose of the data obtained from a survey of e x i s t i n g o f f i c e s was to as c e r t a i n : (1) The respondent's subjective response to various sounds. (2) Physical measurements of the noise climate. The above data was obtained through the d i s t r i b u t i o n of a s e l f -administered questionnaire and i t s c o r r e l a t i o n to objective measurements of the sound f i e l d . Subjective a r t i c u l a t i o n index measurements were then correlated with objective screen sound attenuation t e s t s . As mentioned before, the purpose of t h i s thesis i s to extend the work of Geiger and Hamme as a contribution to the e x i s t i n g findings of the sound absorptive c h a r a c t e r i s t i c s of o f f i c e space. The survey indicated that an objective a c o u s t i -ca l guidelines could be developed for e x i s t i n g open plan o f f i c e s . The Samples Studied. Four companies, with o f f i c e s on seven f l o o r s , were chosen f o r study, each sample with an 48 average of 250 occupants and with functions ranging from purely c l e r i c a l duties to machine operation and including a number of professionals and executives. As part of the analysis of each sample, a s t a t i s t i c a l d e s c r i p t i o n , including diagrams and simple measures (such as average values of general o f f i c e noise recording, screen attenuation and speech privacy c r i t e r i a ) are presented to c l a r i f y the r e s u l t s obtained. The B u i l d i n g . A l l the buildings i n which the o f f i c e s are located were s i m i l a r i n design, with modern open plan layouts,, c e n t r a l core and c o r r i d o r s . Three of the companies overlook major downtown streets and are consequently subjected to some external noise. The remaining sample receives l i t t l e noise from outside except for intermittent a i r c r a f t noise (see Figs. 3.1 to 3.4b p. 49). I n t e r i o r . The pattern of r e p l i e s to the questions, which concerned s a t i s f a c t i o n with the o f f i c e i n general (other than noise) showed the sample to be reasonably homogeneous. With regard to the respondents themselves, observations indicated that there was a marked association between sex and type of work, i n that men tended to be engaged i n duties of a supervi-sory nature r e q u i r i n g concentration, while women more often were employed i n routine tasks, such as machine work. 49 FIGURES 3.1 to 3.4b The Existing Office Plans Survey Samples Compiled by Writer. Showing: Measurement Locations Speaker Orientation Screen Location 50 I G»o'- o'' 1 ) KAPILANO 100 FLOOR 2ND FIG. 3.1 FIG. 3.1 - Loc. 4 54 2) 1090_ V/. PENDER FLOOR 8TH . FIG. 3.2a 56 3 ) 5 9 5 BURRARD FLOOR 2 N D F I G . 3 . 3 - Loc. 2 5R 4) 200 GRANVILLE FLOOR 24TH.. F I G . 3 . 4 b 6 3 64 3.2 SUBJECTIVE TESTING AND OBJECTIVE MEASUREMENTS 3.2.1 Acoustical Considerations and Occupant Questionnaire The following i s a b r i e f outline of each building along with comments. F i e l d notes regarding s i t e v i s i t s include information on each o f f i c e layout, .furnishings, masking sound and analysis of data obtained by the questionnaire. 3.2.1 (1) Kapilano 100, West Vancouver The b u i l d i n g i s situated i n Park Royal, West Vancouver, and thus o f f e r s the occupants many lunch-hour amenities. It i s a new b u i l d i n g and s p e c i f i c a l l y designed for o f f i c e use. One of the i n t e r e s t i n g features i s the 4'0" x 4'0" c e i l i n g grid with recesses of 1'6" for l i g h t f i x t u r e s . Generally i t i s a square layout with central core, size 100'0" x 100'0" and approximately 10,000 square feet per f l o o r . The sample, taken on the second f l o o r ( Fig. 3.1 p. 50) has the highest density of approximately 38 employees at 150 square feet net area per person. The c e i l i n g height i s 9'0", with a plastered surface. Lighting i s of medium density. The windows have tin t e d glass and are covered with sun drapes. Nevertheless there i s a serious heat problem, p a r t i -c u l a r l y in the summertime. Generally the wall i s covered by wood panelling or v i n y l covering. Carpeted f l o o r helps to reduce ac o u s t i c a l problems. Screen b a r r i e r s : The screens used are: a) 6'0" x 5*0" and b) 4'0" x-7'0". 65 The o f f i c e layout: separates the noisy a c t i v i t i e s such as the Xerox room from quiet areas. Different s i z e screens are used at natural corners of t r a f f i c flow. (For f l o o r l o cation of screens see F i g . 3.1 p. 50.) 3.2.1 (2) 1090 West Pender Street, Vancouver 66 This b u i l d i n g i s located i n downtown Vancouver, and so also o f f e r s to the employees lunch-hour diversions. The b u i l d i n g i s about three years old and designed for o f f i c e use. It i s served by three elevators located at one side of the b u i l d i n g . A l l f l o o r s are designed to provide maximum f l e x i b i -l i t y i n o f f i c e s i z e and arrangements, s i z e (120'0" x 65'6") or approximately 7,920 square f e e t . As the t h i r d and eighth f l o o r s have the most a c t i v i t i e s , they were chosen for test purposes (Figs. 3.2 to 3.2a p. 52). Occupancy density some-what higher on the t h i r d f l o o r than on the eighth f l o o r i s on the average 150 square feet per person. The c e i l i n g height i s 9'0", f i b e r g l a s s material with less than medium l i g h t i n g f i x -ture density. Wall/window: Generally the window area i s about 80% v e r t i c a l surfaces. Tinted glass i s covered with drapes. Walls are painted and a l l f l o o r s are f u l l y carpeted. Screen b a r r i e r s ; The screens used are: c) 5'10" x 5'10", d) 6'0" x 4'0", and e) 5'0" x 5'0". Professional employees on the t h i r d f l o o r are given more screens; therefore i t appears higher density. The administrative s t a f f on the eighth f l o o r are given fewer screens with the exception of managerial s t a f f . It appears that screen layout does not separate noise a c t i v i t i e s at a l l . The separate area with noisy machines i s occupied by several employees with-out screens. Throughout the day the open door gives an impression that t h i s area i s part of the general o f f i c e 67 and the noise intrudes intoquiet areas. (For f l o o r location screens see F i g . 3.2a p. 54.) 68 3.2.1 (3) 595 Burrard Street, Vancouver This b u i l d i n g i s located i n the downtown area. This recently b u i l t structure was designed for o f f i c e use. The sample was taken on the 24th f l o o r and i s occupied by Pember-ton Securities Ltd. (Fig. 3.3 p. 56) performing various tasks such as d i s t r i b u t o r , dealer, public u t i l i t y of i n d u s t r i a l and r e a l estate s e c u r i t i e s . The f l o o r layout i s rectangular with a c e n t r a l core, si z e 118'0" x 146'0", with approximately 17,000 square feet per f l o o r . There i s a medium density of occupants per f l o o r with net f l o o r area per person of approxi-mately 160 square f e e t . The c e i l i n g height i s 9'0", f i b e r g l a s s material, with less than medium density of l i g h t i n g f i x t u r e s . Wall/windows: Generally there i s a large window area covering approximately 75% of the wall surface. The t i n -ted glass i s covered with drapes. Walls are covered with v i n y l . Floors are f u l l y carpeted. Screen b a r r i e r s : The screens used are: f) 5'0" x 4'7", and g) 5'0" x 5'7". It appears that a minimum number of screens are used very e f f e c t i v e l y . The o f f i c e layout separates noisy a c t i v i t i e s such as sales from quiet areas sich as conference rooms or the r e c e p t i o n i s t . There are d i f f e r e n t sized screens determined by the employee's func-t i o n . Masking sound system: This i s the only o f f i c e studied that uses a masking sound system. Consulting a c o u s t i c a l engineers were involved i n the o r i g i n a l design concept. 3.2.1 (4) 200 G r a n v i l l e Street, Vancouver 69 This b u i l d i n g i s situated at the end of Granville' Street, adjacent to Burrard I n l e t . This i s a new building p a r t i c u l a r l y designed for o f f i c e s . Cominco Ltd., which operates as a mining, r e f i n i n g , chemi-c a l , exploration and holding company conducts one of the p r i n c i -pal mining, m e t a l l u r g i c a l and chemical enterprises i n Canada. The sample studied (Figs. 3.4 to 3.4b p. 58) i s the head o f f i c e of the company, with three f l o o r s chosen to give a cross-section of t h e i r a c t i v i t i e s , the employees' subjective response to the noise and i t s c o r r e l a t i o n to the r e a l s i t u a t i o n obtained by physical measurements of the noise climate. A rectangular f l o o r layout with c e n t r a l core has an approxi-mate size of 138'0" x 92'0" with about 12,600 square feet per f l o o r . There are approximately 65 employees per f l o o r , with net f l o o r area of 120 square feet per person generally and 150 square feet per person located alongside the windows. The c e i l i n g i s 9'0" with the lowest q u a l i t y of c e i l i n g t i l e . I t appears that l i g h t i n g f i x t u r e density i s very low. Wall/window: Because of i t s long narrow shape of layout, the most v e r t i c a l areas are of t i n t e d glass covered -with drapes. The remaining wall area i s v i n y l covered or painted. A l l f l o o r s are f u l l y carpeted. Screen b a r r i e r s : The screens used are: h) 4'0" x 5'0", and i ) 5»10" x 5'10". From the attached f l o o r plans i t i s obvious that on each sample f l o o r there i s a medium screen bar-r i e r density. There are d i f f e r e n t sized screens plus hanging ple x i g l a s s with a noisy machine area on the 23rd f l o o r . (For f l o o r l o c a t i o n of screens see F i g . 3.4a p. 60.) 70 Occupant Questionnaire Four companies, with o f f i c e s on seven f l o o r s , were chosen f o r study, each sample with an average of 250 occupants and with functions ranging from purely c l e r i c a l duties to machine operation and including a number of professionals and execu-t i v e s . Altogether, 159 questionnaires were issued, of which 147 were .completed; 34 were obtained from Kapilano 100, 20 from 595 Burrard Street, 59 from 200 Gr a n v i l l e Street and 34 from 1090 West Pender Street. Subsequent analysis of the questionnaire material and the noise recordings indicates that the response to noise may be accounted for by two physical para-meters, the average l e v e l measured and the number per minute of impact sounds r i s i n g s u b s t a n t i a l l y above the background l e v e l , which may be c o r r e l a t e d with a d i r e c t measure of a c c e p t a b i l i t y . The o f f i c e samples studied were s i m i l a r and could therefore be combined to form the t o t a l sample. Every member of s t a f f in each o f f i c e was handed a questionnaire by t h e i r manager. The apparatus for recording and measurement was stated. The preliminary study enabled a b r i e f and e a s i l y answered questionnaire to be designed: (1) The f i r s t part was designed to y i e l d an o v e r a l l assessment of the environment and the r e l a t i v e p o s i t i o n of noise. (2) The next part was concerned with screening of the sound source with response to the speech interference assessment. (3) The next was concerned with the var i a b l e s which might govern response to noise such as personal or job c h a r a c t e r i s t i c s with response to the l e v e l of concentra-71 t l o n r a t i n g . (4) The next part was concerned with the subjec-t i v e e f f e c t s and the q u a l i t a t i v e aspects of the Visual or Speech Privacy r a t i n g . (5) The l a s t part of the questionnaire r a t i n g i s concerned with employees' expectation which might govern response to noise such as r e l o c a t i o n or enlargement of work sta t i o n on one hand or enclosed o f f i c e s on the other. • F i n a l l y , space was l e f t i n which the respondent was i n v i t e d to comment f r e e l y on the problem of open plan o f f i c e . Replies to the questionnaire resulted i n an e f f e c t i v e return rate of about 93%. Nevertheless, most of the question-naires were answered p a r t i a l l y . No accurate assessment of i n d i v i d u a l noise tolerances would be obtained from the r e p l i e s received to the questionnaire (see Appendix A.2 and Tables 3.3 to 3.6 p. 151.) The questions dealing with job analysis showed that verbal communication generally played a small part in o f f i c e routine. The respondents engaged i n tasks r e q u i r i n g concentration did l i t t l e work which made noise, while the duties of those performing noisy tasks r a r e l y c a l l e d f o r a great deal of concentration. Whether or not the task being performed requires a high or low l e v e l of concentration i s an important c r i t e r i o n for determining the need for privacy. An analysis of the data, following each o f f i c e sample d e s c r i p t i o n , was obtained by observation and through the use of the questionnaire (see Appendix A . l ) . The study of o f f i c e workers' comments indicated that the main complaint was the l e v e l of o f f i c e noise and lack of speech privacy. But on the same questionnaire the workers f e l t background noise never i n t e r f e r e d with conversational 72 speech l e v e l s . The o v e r a l l r a t i n g of the Summary Questionnaires i s as follows (see Table 3.1 p. 73): (1) Data obtained on the physical environment, work sta-tion l o c a t i o n , the employee's o r i e n t a t i o n and the general noise l e v e l demonstrated an acceptable physical environment i n 32.3% of cases. (2) People usually become used to working close to noise source even when physical measurements showed the noise l e v e l to be unacceptable. This kind of noise c a r r i e d no information, quiet conversation, hal f heard were more disturbing to the concentration than high mechanical noise lev e l s and generated f a r more complaints. (3) This part was concerned with the i n d i v i d u a l work a c t i v i t i e s . It demonstrated 66.4% pr o f e s s i o n a l -production to 33.6% of c l e r i c a l - p r o c e s s i n g . a c t i v i t y . This suggests that concentration requires a f a i r l y quiet environment. (4) In t h i s part o f f i c e employees f e l t t h e i r v i s u a l privacy to be more than adequate but the i r speech privacy less than adequate. (5) Questionnaire response to general employees expecta-tion was very low (39.3%). 5.8% to 9.3% of the employees wish to relocate or enlarge t h e i r work st a t i o n s . However, v/hen a change i s desired at least 25% of respondents seek the status of a private o f f i c e . To compare the questionnaire r a t i n g and r e a l physical ( 1 ) SUMMARY CHART.OF. THE QUESTIONNAIRE. BATING (2) ' (3) (4) (5) BLDC. ff ADDRESS KAPILANO 100 5 9 5 BURRARD '4 200 GRANVILLE n 1090 W. PENDER Ml TOGETHER! (AVERAGE) FLOOR 2nd 24th 2 2nd 23rd 24th 3rd 8th ^ SAMPLES & ANSW. 39/34 20/20 20/19 20/20 20/20 20/16 20/18 159 147 PHYSICAL ENVIRONMENT <® W.ST FACING WINDOW 56% 25% 72.2X 802 50* 46.8% 26; 3% 50% GEN. NOISE LEVEL INSIDE OFFICE Accept Bad Und Accept Accept Very Bad Very id OUTSIDE OFFICE Quiet Very Quiet Very Quiet Very Quiet Very Quiet Normal Very Quiet WHITE NOISE BAD I VERY TO i QUIET ACCEPT.I TO 1 NORMAL N i l Yea N i l N i l N i l N i l N i l NIL t£ ACCEPTABLE LOCATION OF SOUND SOURCE fa OFFICE MACHINE Enclosed Room Open Area Open Area Part. Cloned Part. Closed Open • Area Part . Closed SPEECH. INTERF. Neutral ',css thnnl Neutral Mnrc thnnl Neutral. Lena than; Neutral Neutral Lens Than Neutral D i s s a t i s -f ied P.CLOSED DISSAT. TO 1 TO OPEN | LESS THAN .' J_N£UTRAL V NOT ACCEPTABLE INDIV. WORK ACTIVITIES PROF ESS IONAL 85% 95% 90% 5% 90% 95% 5% CLER ICAL 15% 5% 10% 95% 10% 5% 95% SATISFACTION OF THE OBSERVER VISUAL PRIVACY Average Low Above Above Average Aver. Above Above Aver. Aver. Above Avor, Aver. Above Above Aver, Aver. Average Low Average SPEECH PRIVACY Low 66,4 y> 33.6 AVERAGE LEVEL OF CONCENTRAT V" ION AVERAGE1 LOW TO ! TO ABOVE | ABOVE AVERAGE| AVERAGE • V AVERAGE GEN. EMPLOYEES EXPECTATION: W.S. TO RELOCATE 0% 5% 0% 0% 10% ; 0% 26.3% W.S. TO ENLARGE 6.72 0% 11% 5% 5% 26.6% 10.5% TO 10% TO 10% •4-ENCL OSED OFFICE 20% 20% 27.8% 30% 25% 46.6% 10.6% TO 25% NO RES POND 63.2% 65% 55% 45% 47.4% TO 55% V LESS THAN AVERAGE TABLE 3.1 74 sound levels measurements were taken for each o f f i c e . The only complaints were about loss of concentration due to overhearing. In conversations, voices were often raised above background noise, but there were few (5.8%) complaints about that noise. High l e v e l s (43-47 dB) of background noise are not nearly as disturbing as c l o s e r information carrying noise or a noisy machine (e.g. a t y p i s t ) i n a less active area. 7 5 3.2.2 Measurement of the Acoustical C h a r a c t e r i s t i c s of the O f f i c e s The measurements described here were performed in four d i f f e r e n t o f f i c e s which had standard physical properties. Even though we are mostly concerned with evaluating the degree of speech privacy, we must keep in mind the o v e r a l l e f f e c t of the general noise l e v e l . Therefore, a prime object of the study i s the determination of the general noise l e v e l and the recording of the mean attenuation. These objective t e s t s provide the data to determine the actual degree of speech privacy. The importance of t h i s section remains with the understanding of test performance and i t s c o r r e l a t i o n with the tests approved. 3 . 2 . 2 - 1 The General Sound Level Assessment A b r i e f d e s c r i p t i o n of each of the locations where measurements were obtained i s given in Figs. 3.5 to 3.8 p. 7 6 . The equipment used i s described i n F i g . 3.9 p. 8 0 . At each of these locations, the sound pressure l e v e l was measured i n dBA, dBC and i n octave bands from 1 2 5 - 4 0 0 0 to give the frequency spectrum. Tape recordings also were made and analyzed to. determine the s t a t i s t i c a l i n d i c e s , L^Q? L ^ Q ' A N <^ L 9 0 ^ ^ - 9 * 3 . 1 0 p. 8 1 ) . Average Sound Level. The readings were taken by means of a portable sound l e v e l meter i n dBA and dBC at each l o c a t i o n throughout the o f f i c e f l o o r s . Since th i s l e v e l varied from moment to moment, the l e v e l most frequently indicated by meter over a period of 1 0 - 1 5 seconds was taken as the "average" on 76 MEASUREMENT LOCATIONS #1 KAPILANO 100: FLOOR 2 LOCATION OCCUPATION Investigation Pollution Control Pollution Control Receptionist Pollution Control Pollution Control Pollution Control Pollution Control Librarian COMMENT Typing Typing, Telephoning Typing, Telephoning Telephoning, Some Conversation Typing, Some Conversation Typing, Some Conversation Typing, Some Conversation Typing, Some Conversation F i l i n g , Some Typing FIG. 3.5 #2 1090 W. PENDER: FLOOR 3 LOCATION OCCUPATION Technician Senior Biologist Senior Biologist COMMENT Technical Writing Some Conversation Writing #2 1090 W. PENDER: LOCATION L4 L5 L6 L -7 FLOOR 3 (cont'd) OCCUPATION Senior Biologist Senior Biologist Manager Technician #2 1090 W. PENDER: FLOOR 8 LOCATION OCCUPATION Supporting Staff Supporting Staff Mail Room L^ Biologist L,. Administration L Executive o 77 COMMENT Reading Telephoning Telephoning, Writing Technical Writing COMMENT Counting, Writing Counting, Writing Mail sorting. Occasionally a l l machines were in use at the one time. Writing, Telephoning Calculating, Typing Telephoning Telephoning, Meeting FIG. 3.6 78 #3 595 BURRARD STREET: FLOOR 24 LOCATION OCCUPATION L^ Professional Sales Professional Sales L 3 Trading L, Professional Sales 4 L,. Sales Executive 'L Professional Sales 6 L., Executive Area #4' 200 GRANVILLE: FLOOR 22 LOCATION OCCUPATION Clerk Geologist Geologist Technician Geologist COMMENT Telephoning, Writing Telephoning, Writing Telephoning, Writing Telephoning, Writing Some Conversation, Telephoning Writing Telephoning, Writing Interview, Meeting FIG. 3.7 COMMENT Typing, Telephoning Telephoning, Writing Telephoning, Writing Technical Writing Telephoning, Writing (Cont'd) #4 200 GRANVILLE: FLOOR 23 •79 LOCATION J10 J l l J12 OCCUPATION Adminis trator Librarian Mail Room Professional Professional Receptionist Clerk COMMENT Conversation, Meeting F i l i n g , Typing Mail Sorting, Machine Operation Telephoning, Writing Telephoning, Writing Telephoning, Conversation Typing, Telephoning FLOOR 24 J13 J14 J15 J16 J17 J18 J19 Clerk Managerial Area Supervisor Professional Professional Assistant Manager Clerk Typing, Telephoning Meeting, Interviewing Telephoning, Meeting Telephoning, Writing Telephoning, Writing Telephoning, Meeting Typing, Telephoning FIG. 3.8 EQUIPMENT USED SOUND LEVEL METER: TAPE RECORDER: MEASURING AMPLIFIER: GRAPHIC LEVEL RECORDER: DISTRIBUTION ANALYSER TYPE 2204 BRUEL & KJAER TYPE - Uher 4000 REPORT L B & K 2606 BRUEL & KJAER 2305 B & K 4420 81 U S E WITH G T H E R I N S T R U M E N T S % TA RE . P£coRr^t> - 4000 Uh.<Ln Set up for rscoraing sound v> 1 2606 2305 S i l l © o r a w jmiiJ j MHA6.UCJN& AMpLlFI&fl LEVEL R^ OOR.DE-f2- Dl ST. AWAL . Y S E L R SET UP FOR ANALYZING DATA TO YIELD CUMULATIVE NOISE DISTRIBUTION FIG. 3.10 EQUIPMENT USED: 82 _50U NO SCREEN ' C E I l_l N £ IboAft PS J N S T A U L C O VVJ E K P O S E D euSpCN TAPE RECORDER 4N4r - 4000-L ( © ) (( G )) & o AMPLIFIER: TA-957, TOA LOUDSPEAKER: Telefunken HI-FI Z = 4 White Sound Sourc 4U5 2619 TRIPOID & CABLES SOUND LEVEL METER RECORDER 2204 BRUEL & KJAER FIG. 3.11 8 3 each occasion. Readings were taken at a number of d i f f e r e n t points. (Locations are shown on the attached layout plan -see F i g s . 3 . 1 to 3 . 4 p. 49.) This procedure was repeated at i n t e r v a l s during the working day. By c a l c u l a t i n g the a r i t h -metic mean of a l l these readings, an average l e v e l was obtained for each o f f i c e . Tape recordings of o f f i c e noise l e v e l s were taken in each o f f i c e for f i v e minute periods at i n t e r v a l s throughout the working day. These recordings were analyzed in a laboratory for noise content (to determine a dominant sound - i . e . t r a f f i c , c e r t a i n machines or human voice and to y i e l d the s t a t i s t i c a l d i s t r i b u t i o n i n d i c e s , L ^ Q ? L 5 Q » A N < 3 L 9 0 ^ * T ^ E s t a t i s t i c a l indices L ^ Q , L 5 Q > A N D L 9 0 ' a r e c o r r " e l a t e d with E.G. Keighley f i n d i n g s . ( 1 ) 3 . 2 . 2 - 2 Objective Screen Attenuation Assessment The measurement of sc r e e n / c e i l i n g attenuation was made using a method following the recommendations by the U.S. Public Building Service Standards PBS - C . 2 ( 2 ) (based on objective measurements including methods f o r the rat i n g of fun c t i o n a l Interzone Attenuation and NC). This test consists of placing a loudspeaker 6 ' 0 " i n front of a screen at a height of 4 ' 0 " and then measuring the 5 0 0 - 2 0 0 0 Hz octave band attenuation between a reference point 3 ' 0 " i n front of the loudspeaker and points l y i n g between 9 - 1 2 feet on the other side of the screen. For measurement positions and equipment used see F i g . 3 . 1 1 p. 8 2 . The attenuation values as per each screen are shown i n Figs. 3 . 3 0 to 3 . 3 4 pp. 1 1 5 and 1 1 6 . 84 50 WORD RHYMING TEST FOR SUBJECTIVE MEASUREMENT OF ARTICULATION INDEX A B C D E 1 bat bfJch bash bass bad^e 2 laws long log lodge lob 3 wig with wit wilck wick 4 dumb dvb doth duji dove 5 cuff cub cut ' cup cud 6 dig din did dim dill 7 dun dud dung dub dug S fill •fig.-- fin fizz fib 9 leave liege taj leach leash lead 10 toss long talks leg 11 lash lack lass laugh lath 12 mat mad math man mass 13 beige base bayed bathe bays 14 pass path pack pad pat 15 peak peas peal peace peat 16 pick pit pip Pig pitch 17. pup puff pub . puck pus 18 hath hash half here has 19 we're weal weave weed wean 20 sad sat sag sheathe ' sack sap 21 sheen sheave sheath sheaf 22 sing sip sin sit sick 23 sud sum sub sun sung 24 tab tan tam tang teel tap 25 •teethe tear tease teeth 26 led shed red wed fed 27 sold cold hold told gold 28 dig wig big rig pie 29 kick . chick thick pick sick 30 fin tin shin kin . thin 31 bark , dark mark lark park 32 . gale pale . tale bale male 33 peel will feel eel heel keel 34 hill kill till bill 35 feci reel seal zeal veal 30 shame game came same lame 37 ten pen den hen then 3S pin sin tin win fin 39 thin tin chin shin gin 40 thee dee lee knee • zee 41 rent bent went dent tent 42 hip rip tip dip lip 43 top hop pop cop shop 44 yore gore wore lore roar 45 vie ' thy fie thigh high 46 zip lip nip zyp ship 47 nest best vest rest west 48 bust just rust gust dust 49 met vet that fcl rat 50 way may they nay The stimulus words arranged according to Test Forms A - E . Each column represents a test. Each row represents a re-, sponse set. In the first 25 rows, the contrasting clement is the final consonant; in the last 25 rows, it is the initial consonant. The italic words are new words, the others are from House el c/.a • Taken from J.D. G r i f f i t h , "Rhyming M i n i m a l C o n t r a s t s : A S i m p l i -f i e d D i a g n o s t i c ' A r t i c u l a t i o n T e s t " , J . A c o u s t . Soc. Am. 42, 1, 196 7. FI G . 3.12 3.2.2 - 3 Subjective A r t i c u l a t i o n Index Assessment 85 Objective measurements were made to determine the attenuation of sound at s p e c i f i e d distances. Subjective measurements of speech privacy were made using a test developed by J.D. G r i f f i t h s . ( 3 ) This method, A S i m p l i f i e d Diagnostic A r t i c u l a t i o n Test, may be u t i l i z e d in a f u l l y occupied o f f i c e in which general background noise i s present or by providing a v a r i a b l e , a r t i f i c i a l background noise by the use of a white noise source and a loudspeaker. The l a t t e r method was selected. Figure 3.13 p. 86 presents the screen , positions f o r the administration of the above t e s t . Two subjects are seated at a distance of 3'0" from the center l i n e of an o f f i c e screen, facing the screen on opposite sides (as shown i n F i g . 3.13, A,B, &C, p. 86). Each subject a l t e r n a t e l y reads from a l i s t of 250 phonetically balanced words (Fig. 3.12 p. 84). The reader marks his word choice, while the l i s t e n e r on the opposite side of the screen marks what he thinks he hears. Two sets of data were c o l l e c t e d for each screen. A forced choice from f i v e possible word selections gives a chance score of 20% correct on the te s t . From J.D. G r i f f i t h s ' work the a r t i c u l a t i o n index i s such that A l = 0 for a chance score of 20%. This method i s therefore not suitable for testing " e x c e l l e n t " speech privacy requirements of Al <C 0.2.(4). The p r o b a b i l i t y of obtaining a chance score less than 20% correct can be obtained by, using a modified version of G r i f f i t h s ' t e s t , employing a word l i s t of 1000 phonetically balanced words. In thi s case the l i s t e n e r has to make a 86 SCREEN TESTING POSITIONS • ii 6-0 1 A B B n 1 u B B B i n 6-0 B i © . . t I 6-B B B B B B B II 0 i 1 o C 1 © — 1 B B 1 B B B 39 B33 ES EES tjg © Screen Reader Li s t e n e r FIG. 3.13 8 7 choice from a s e l e c t i o n of twenty words. From a forced choice of 20, the minimum chance score i s reduced to 5%. T h e o r e t i c a l l y t h i s test, by assuming AI = 0 with a chance score of 5%, lessens the chance for error and increases the accuracy for the evaluation of "excellent" speech privacy condition. Unfortunately the modification of the G r i f f i t h s ' test i s not easy. The best a p p l i c a t i o n of test data to modified ANSI - S.3 data has been studied by A.C.C. Warnock, (5) ("Acoustical Privacy in the Landscaped O f f i c e " , NRC 13435 Ottawa). 3.2.3 Results and Analysis of Data Having obtained objective measurements i n four sample o f f i c e s (Section 3.2.2) we s h a l l now proceed to analyse the data and c o r r e l a t e these findings with approved ac o u s t i c a l standards for each t e s t . The subjective reactions to the noise lev e l s obtained i n these o f f i c e s w i l l be discussed i n r e l a t i o n to the objective measurements i n section 3.4. 3.2.3 - 1 General Sound Level Measurements Noise l e v e l measurements were conducted at locations throughout each o f f i c e f l o o r . The r a t i o n a l for obtaining these measurements was to obtain quantitative data on: a) present background noise l e v e l s , b) t y p i c a l "peak" or maximum noise l e v e l s , c) the s t a t i s t i c a l d i s t r i b u t i o n of the noise l e v e l s . For the p a r t i c u l a r sound sources and t h e i r locations see Figs.'3.5 to 3.8 p. 75. At each of these locations the sound pressure l e v e l was recorded i n dBA, dBC and i n octave bands 88 from 125-4000 Hz to give the frequency spectrum. The graphical presentation of these sound l e v e l measurements are shown in Figs. 3.26 to 3.29b p. 103. The range of values, on the whole f l o o r f a l l well above levels of an ideal spectrum of NC = 40 for a general o f f i c e , as determined by NC (noise c r i t e r i a ) . Usually NC = 40 approximates a t y p i c a l active o f f i c e . (6) It should be noted, however, that i n t e r n a l noises may not be so c r i t i c a l since they may be c o n t r o l l e d . For example, typewriters can be stopped while a telephone conver-sation i s in progress. A s t a t i s t i c a l d i s t r i b u t i o n analyzer was used to determine the cumulative d i s t r i b u t i o n of the sound l e v e l s within a s p e c i f i e d time and data i s presented in the form of d i s t r i b u -t i o n curves (Figs. 3.20 to 3.25 p. 96). Tape recordings of o f f i c e noise were taken and shown in graphical form (Figs. 3.14 to 3.19 p. 89). Throughout the o f f i c e s the sound l e v e l s were generally within an acceptable range ( 50 dBA). However, in areas where s p e c i a l i z e d machines ( i . e . mail machine) produced continuous noise, the sound pressure levels were often above 50 dBA f o r extended periods of time. (See F i g s . 3.2a p.54, 3.19 p. 95 for layout location and tape recording graph.) 3.2.3 - 2 Objective Screen Attenuation Testing These measurements were taken for the e f f e c t i v e mean scr e e n / c e i l i n g attenuation of each screen i n a t y p i c a l work st a t i o n p o s i t i o n . The equipment used and how the test was conducted i s shown i n F i g . 3.11 p. 82. The f l o o r plan/screen (A) location i s shown i n F i g . 3.13 p.86. For s i m p l i c i t y , 89 FIGS. 3.14 TO 3.19 GRAPHICAL PRESENTATION OF OFFICE,NOISE TAPE RECORDINGS BrOel & Kjcer A. ::^^::.T:.:ftA • 3 5 ^ " ] & f e < - i D e . .A. OP 1102 LOCATION 1 / FLOOR 3 PEAK INDEX T 1 ; TOTAL - 0 • • o ACTIVITIES: Sp = Some Conversation ' Sc = Secretarial Work Sx = Extensive Speech X = Xerox Machine "' • YLG.^3,,M : ::r : : ._^\55. . . . . . . . :_ . : .. ... . J L & C . . gs> r ~ — r : - " f i f ^ s i g g - A — LOCATION 5 / FLOOR 3 PEAK INDEX T 1; TOTAL =13 ACTIVITIES: Sp = Some Conversation Sc = Secretarial Work i '• • Sx = Extensive Speech / 1 :• FIG.. 3.15 Q P 1102 LOCATION 3 / FLOOR 3 PEAK INDEX T1; TOTAL - 9 ACTIVITIES: Sp = Some Conversation Sc = Secreatrial Work E = Elevator Bell X = X e r o x Machine ' FIG. 3.16 OP 1102 LOCATION 1 / FLOOR 8 . PEAK INDEX T 1; TOTAL - 5 ACTIVITIES: Sp = Some Conversation Sc = Secretarial Work E = Elevator Bell X = Xerox Machine / << ' - -• • -• i . _ _ _ p^> no (zc°&) to,-01' 1102 • . . LOCATION 2 / FLOOR 8 vp PEAK INDEX T 1; TOTAL - 0 ACTIVITIES: Sp = Some Conversation Sc = Secretarial Work _ . St = Extensive Typing ' FIG. 3 . 1 8 ' LOCATION 3 / FLOOR 8 PEAK INDEX T 1; TOTAL - 26 ACTIVITIES: N = Noisy teletype i n operation near by Sp = Some Conversation • ' FIG.,3.19 l io l ' r i. 96 FIGS. 3.20 TO 3.25 GRAPHS SHOWING CUMULATIVE DISTRIBUTION AND SOUNDS ANALYZED 9 7 CUMULATIVE DISTRIBUTION \ 98 CUMULATIVE DISTRIBUTION dBA L " f 3 . 5 Ah A 3D L - A-l S A-hA Loc 5 / F l o o r 3 FIG. 3.21 i 9 9 CUMULATIVE DISTRIBUTION c o JC w 0) a rd > c (0 x: w o <u 0> w o c OJ E •H -P o |00 So' ao 10 bo C o 3o. 20 10 4 0 45 5o 55 dBA 10 [__ - 2Q.5 4&A SO L = 50. JhA 9o hoc. 3 / F l o o r 3 FIG. 3.22 100 C U M U L A T I V E D I S T R I B U T I O N 30 35 AO 45 4-2.5 JSA 3>9£ c\hA 2^5 AZ>A L o c . 1 / F l o o r 8 F I G . 3 . 2 3 1 0 1 CUMULATIVE DISTRIBUTION 1 0 2 C U M U L A T I V E D I S T R I B U T I O N 1 0 3 FIGS. 3.26 TO 3.29 OCTAVE BAND SOUND LEVELS (dBA AND dBC) SHOWING THE NOISE SPECTRUM FOR EACH OFFICE SURVEYED RANGE OF OCTAVE.BAND SOUND LEVELS, dBA AND dBC "T | »~ -' : : I ; : r — . — r — : 1 — i — j — : — p 'SO 3 SO 4r» f 125 250- 500 1000 2000 400C' J0"0 1000 F R E Q U E N C Y IN H&VTZ 10000 ill KAPILANO 100 Second Floor "Silent Day" - An Average Density (For Location Measure See Fig. 3 . 1 ) FIG. 3 . 2 6 RANGE OF OCTAVE BAND SOUND LEVELS, dBA AND dBC , —: » ; I - ; .- . x" i : l : , r — > 1 — l — i - - j ; — - 1 — : ;—* 125 250- 5'00 1000 2000 400U 100 1000 1C000 F R E Q U E N C Y IN H E R T Z #2 - 1090 W. PENDER Third Floor "Normal Day" - An Average Density (For Location Measure See Fig. 3.2) FIG. 3.27 1 0 6 RANGE OF OCTAVE BAND SOUND LEVELS, dBA AND dBC , —: i - T ; r , j - — ; r T « i r—--j-—; ; 1 r 7o \ Go SO 40 •bo 100 125 250' 500 1000 2000 4000 1CC0 F R E Q U E N C Y JM HERTZ NC 45 NC 40 10000 ire. A #2 -1090 W. PENDER Eight Floor "Normal Day" - An Average Density (For Location Measure See Fig. 3.2a) FIG. 3.27a 1000 1C000 F R E Q U E N C Y »N H E R T Z #3 - 595 BURRARD 24t.h Floor "Normal Day" - An Average Density (For Location Measure See Fig. 3.3) FIG. 3.28 RANGE OF OCTAVE BAND SOUND LEVELS, dBA AND dBC 7o 60 90 AO 3o NC45 NC 40 J00 125 250 F R E Q U E N C Y IN" H E - R T 2 500 1000 2000 4000 1C00 1C000 H - 200 GRANVILLE 22nd Floor "On Average Working Day" - An Average Density (For Location Measure See Fig. 3.4) FIG. 3.29 #4 - 200 GRANVILLE 23rd Floor • "Normal Day" - An Average Density (For Location Measure See Fig. 3.4a) FIG. 3.29a RANGE OF OCTAVE SAND SOUND LEVEL ^ S t dBA AND dBC 1 TT" : T - - I ' 2 5 2 5 0 ' 500 ,0700 27o7 1000 u u o ^EQU^.VCY IN HERT2 4000 10000 24th Floor "Normal Day" - A« A FIG. 3.29b I l l octave band measurements were made and evaluated for each screen. The attenuation was measured between points 3'0" and 6'0" from a loudspeaker and up to 21'0" on the other side of the screen. The attenuation values were recorded i n dBA, dBC and an e f f e c t i v e mean attenuation, averaged over the range 500 - 2000 Hz. The objective acoustic guidelines set by Geiger and Hamme provide attenuation references f o r series of conditions for a c o u s t i c a l c e i l i n g s . For example, the Open-Sky  C e i l i n g ("best possible") has attenuation of 25 dB at 9', 27 dB at 21' whereas the t y p i c a l Gypsum-Board C e i l i n g ("least s a t i s f a c t o r y " ) has 20 dB at 9', 25 dB at 21'. How these "standard c e i l i n g s " compared v/ith those of the present o f f i c e sample tests i s shown in the Figures 3.31 to 3.34 p.116 . These show that samples tested have a 25 dB average attenua-ti o n values in the frequency range of 500 - 2000 Hz. 3.2.3-3 Subjective A r t i c u l a t i o n Index Measurements In t h i s test the subjects'were seated as shown in F i g . 3.13 p. 86. The whole process was repeated with d i f f e r e n t sets of subjects. A sample word l i s t i s shown in F i g . 3.12 p. 85. Two sets of data were c o l l e c t e d for screen locations A, Band C f o r each selected sample screen. The percentage i n t e l l i g i -b i l i t y score and corresponding A r t i c u l a t i o n Index was calculated and found in F i g . 2.12 p. 22. A summary of the subjective and objective measurements obtained in t h i s screen test are shown i n Table 3.6 p. 163. The percentage of phonetically balanced words and corresponding AI meets the Acceptable Privacy Conditions. In most cases the 112 average of 20 dB attenuation does exi s t between 6*0" and 21*0" from a sound source as obtained from objective measurements based on average attenuation as suggested by Geiger and Hamme. In general, i t appeared that the sample screens con.tributed to "acceptable" privacy, which corresponds to A l 0.07 to 0.11.(7). 113 3.3 COMPARISON OF THE OFFICE SAMPLE STUDIES TO APPROVED ACOUSTIC GUIDELINES The ac o u s t i c a l design c r i t e r i a for any project are based on a set of guidelines established for acceptable sound c o n t r o l , then adapted to the s p e c i f i c conditions of a p a r t i c u l a r project. Therefore, the s t a t i s t i c a l data of the samples studied w i l l now be correlated with approved acoustical standards, established by E.C. Keighley and by Geiger and Hamme Inc. 3.3.1 Acceptable C r i t e r i a f o r Noise i n Large Offices by E.C. Keighley According to E.C. Keighley, average sound levels of 40 dBA are within the acceptable units of background noise l e v e l s . In the o f f i c e s studied, only the operation of type-writers and some p a r t i c u l a r pieces of equipment cause the background noise l e v e l to exceed the 50 dBA average l e v e l l i m i t (see F i g s . 3.14 to 3.19 p. 89 ). These sources should be considered i n d i v i d u a l l y and steps taken to reduce t h e i r noise l e v e l s i n the work area. O f f i c e a c t i v i t y alone does not produce continuous lev e l s of noise, exceeding 50 dBA due to the r e l a t i v e l y small, narrow siz e of the o f f i c e areas (see F i g s . 3.14 to 3.19 p. 89 ). The graphical form of the octave band sound l e v e l s t e l l us of the average sound l e v e l within o f f i c e samples. The spectrum shape varies per each o f f i c e (see F i g s . 3.26 to 3.29b p. 103). The i d e a l spectrum, i n terms of t y p i c a l frequencies, as shown in F i g . 2.7 p. 20 , should be recommended for such o f f i c e spaces. The d i s t r i b u t i o n curves t e l l us what kind.of noise i s i n the o f f i c e . For accurate 114 values of dBA see d i s t r i b u t i o n graphs (Figs. 3.20 to 3.25 p. 96 ). S t a t i s t i c a l l e v e l s : L ^ Q ? L 5 Q J LgQ i - n dBA give us an idea of peaks ( L ^ Q ) , an average mean ( L ^ Q ) , or a general back-ground noise ( L ^ Q ) . The L ^ Q l e v e l represents the transient in S P L due to i n d i v i d u a l sources, while the L ^ Q l e v e l i s a good i n d i c a t o r of the general background l e v e l . According to the r e l a t i o n s h i p between average l e v e l and ac c e p t a b i l i t y f o r d i f f e r e n t values of the peak index (T^) by E.C. Keighley, the o f f i c e samples had 97-98% a c c e p t a b i l i t y with the exception of the s p e c i a l i z e d machines room which had 47% a c c e p t a b i l i t y ( F i g . 3.19 p. 95 ). Therefore, i t i s apparent that the above test data meet the "acceptable" c r i t e r i a for sound control i n large o f f i c e s as s p e c i f i e d by Keighley. 3.3.2 Test Method - PBS - C.2 (1972) by Geiger and Hamme Inc. The open sky and gypsum board c e i l i n g tests performed by Geiger and Hamme provided "best possible" and "least s a t i s f a c -tory" sound attenuation references for a series of ac o u s t i c a l c e i l i n g s . In comparison to the guidelines set by these researches,'the data from t h i s writer's samples f a l l only s l i g h t l y above the "least s a t i s f a c t o r y " range established by Geiger and Hamme (see Fi g s . 3.30 to 3.34 p.116 ). The graphical presentation of screen attenuation r e s u l t s t e l l us that 75% of tes t samples f e l l below the "standard b u i l d i n g c e i l i n g " range (see F i g . 3.30 p.115). Therefore, i t becomes exceedingly c l e a r that in the samples chosen, the c e i l i n g SUMMARY CHART OF OBJECTIVE SCREEM/CE RING ATTENUATION TESTS 115 O B J E C T I V E C O M P A R I S O N O F O P E N - P L A N C E I L I N G - P L E N U / A S Y 5 7 E.V . 5 I N T E R M S O F S C R E E N S H A D O W I N G P O T E N T I A L 6 9 12 )5 18 D I S T A N C E F R O M S O U R C E (FEET) FIG. 3.30 1 1 6 . . . . . O B J E C T I V E C O M P A R I S O N O F O P E N - P L A N C E I L I N G - P L E N U M SYST£/.-\5 I N T E R M S O F S C R E E N S H A D O W I N G P O T E N T I A L 30 25 2 0 15 O P E N - S K Y C E I L I N G T A R G E T C E L L I N 10 D E S I G N O B J E C T I M E j i : 1*4 G Y P S U M - B O A R D C E I L I N G F R E E - F I E L D S P R E A D I N G 9 12 15 18 D I S T A N C E F R O M S O U R C E ( F E E T ) 21 til KAPILANO 100 CEILING = /i'O" x 4'0" grid recess SCREEN « a) C-O" x 5i0" b) it 10" x 7J10" FIG. 3.31 1-1 / OBJECTIVE COMPARISON OF OPEN-PLAN CEILING-PLENUM SYSTEMS IN TERMS OF SCREEN SHADOWING POTENTIAL 30 25 20 15 OPEN-SKY CE1LIN 10 11 ft A DESIGN § OBJ ECTIVE ***** GYPSUM-BOARD CEILING FREE-FIELD SPREADING 9 12 _ 15 18 DISTANCE FROM SOURCE (FEET) 21 #2-1090 W. PENDER CEILING: SONOGLASS NUBBY 3/4" SCREEN: c) S-'-lO" x 5 -10" d) 6 i 0 " x 4*~ 0" e) 510" x 5-'0" FIG. 3.32 1-18 - O B J E C T I V E C O M P A R I S O N O F O P E N - P L A N C E I L I N G - P L E N U M S Y S T E M S IN T E R M S O F , . . S C R E E N S H A D O W I N G P O T E N T I A L tu 6 9 12 15 18 21 D I S T A N C E F R O M S O U R C E ( F E E T ) $3 - 595 BURRARD CEILING: SONOCOR FIBERGLASS l " .. c > . ^ . . . FIG. 3.33 SCREEN: £•) 5-'0" x 417" g) 5i0" x 5)7" 1 1 9 O B J E C T I V E C O M P A R I S O N O F O P E N - P L A N C E I L I N G - P L E N U M SYSTEMS I N TERMS O r S C R E E N S H A D O W I N G P O T E N T I A L U Z < f— CO Q t o Z I* J II.1 • <u O u > CO if) i—• X 30 25 20 15 10 O P E N - S K Y C E I L I N G D E S I G N I O B J ECT1\E \ TARGET C E L L I N G G Y P S U M - B O A R D C E I L I N G 12 15 18 21 04 - 200 GRANVILLE D I S T A N C E F R O M S O U R C E (FEET) CEILING: SONAGLASS NUBBY 3/4* SCREEN: h) 4-'-0" x 5^0" FIG. 3.34 120 materials provided poor attenuation properties as measured by objective standards. D i f f e r e n t sizes-of tested screens were found to have almost no e f f e c t i n terms of screen shadowing p o t e n t i a l . According to Geiger and Hamme i t i s desirable to design a c e i l i n g system that provides at least an average of 20 dB attenuation between 6 feet and 21 feet from a sound source (assuming the use of intervening screen). Our samples do meet t h i s requirement. However, while comparing d i f f e r e n t s i z e screens i t must be remembered that c e i l i n g s were of d i f f e r e n t q u a l i t i e s i n each o f f i c e . According to the r e s u l t s obtained i t i s not worthwhile to have d i f f e r e n t sizes of screens ( F i g . 3.30 p.115). Based on the r e s u l t s of these tests i t would appear that a decision on d i f f e r e n t screen sizes would need to be c a r e f u l l y co-ordinated with the c e i l i n g system and background noise l e v e l and d i s t r i b u t i o n . In the conclusion the writer advises a designer to require a c o u s t i c a l c e i l i n g materials to exceed values above the "standard b u i l d i n g c e i l i n g " range as experienced with test methods PBS - C . l + C.2. The method for v e r i f y i n g Speech Privacy Potential (SPP) based on objective measurements i s contained in test method PBS C.2. The "Guide for Acoustical Performance S p e c i f i c a t i o n s of an Integrated C e i l i n g and Back-ground System" provides guidelines for the acoustical design of the major o f f i c e systems (such as c e i l i n g s , screens and masking systems, e t c . ) . There should also be provision f o r the re-arrangement of the s p a t i a l layout of the o f f i c e s i n accordance with the design objectives for each i n d i v i d u a l 121 project. The choice of screen s i z e , for example, must be based upon the privacy requirements of a given o f f i c e as well as the s p a t i a l and fu n c t i o n a l requirements. 3.3.3 A S i m p l i f i e d A r t i c u l a t i o n Test by J.D. G r i f f i t h s Closer i n v e s t i g a t i o n of both the screen b a r r i e r s in the o f f i c e samples and the measurement data indicated that an "acceptable" speech privacy condition (Table. 3.2 p.122) e x i s t s in most cases. Using G r i f f i t h s ' Test, explained in section 3.2.2-3, the mean subject score for each of the positions shown (A,B,C) was obtained under a r t i f i c i a l background noise, employing a v/hite noise sound amplified through a loudspeaker. The summary chart of the screen testing (Table 3.2 p.122) t e l l s us about the screen size and i t s performance. The mean score was calculated f o r each p o s i t i o n ( F i g . 3.13, A,B,C, p. 86). The mean subjective score i n each po s i t i o n for a l l test conditions was normalized to the score obtained with screen/ c e i l i n g attenuation values. These normalized scores were then averaged to produce the effectiveness of the d i f f e r e n t screen conditions. According to Geiger and Hamme i t i s desirable to design a c e i l i n g / s c r e e n system that provides at least an average of 20 dB attenuation between 6'0" and 21'0" from a sound source (assuming the use of intervening screen). In most cases t h i s was found to e x i s t (see *•* i n Table 3.2 p.122). Further to the assessment of Speech Privacy Conditions as d scussed in the report by L.W. Hegvold (8) the a r t i c u l a t i o n index ranges from zero (for zero communication) to unity for SUMMARY CHART ON THE RESULTS OF THE SCREEN ATTENUATION TESTS BLDG.# TEST. PERFORMANCE AS PER EACH PRIVACY CONDITION ADDRESS SCREEN SIZE SCREEN POSITION (A.B.C) ASSESSMENT* / PHONETICALLY ARTICULATION INTERZONE FROM SUBJECTIVE** FROM OBJECTIVE*** BALANCED WORDS INDEX ATTENUATION TESTING MEASURE A B C A B C A B C A #1 <a>6.'0" x 5.I0" KAPILANO 100 51-64 51-53 60-76 0.16 0.15 0.17 17dB + + + + (j|>4^ 0" x 7-10" 56-60 56-58 51-77 0.15 0.15 ,0.17 17dB + + + + #2 1090 W. PENDEF (C)5'-10" x 5'-10" 43-60 60-69 50-53 0.15 0.17 0.14 23dB + + + + ?|Wo" x 410" 26-67 28-30 50-77 0.13 0.15 0.17 23dB + + + + (1)5^ 0" x 5^0" 57-70 72-79 50-61 0.16 0.21 0.16 17dB + + + + #3 595 BURRARD (1)5.10" x4i7" 72-74 54-66 75-62 0.19 0.16 0.19 23dB + + + + $ 5 1 0 " x 517" 70-72 56-68 55-72 0.17 0.16 0.19 22dB + + + • + #4 200 GRANVILLE (jj)4i0" x 5^0" 58-74 52-53 45-64 0.17 0.15 0.15 20dB + + - + + * BASED ON SUBJECTIVE AND OBJECTIVE TEST INFORMATION ** BASED ON CBD139 - REPORT, JULY 1971, BY L.W. HEGWOLD *** BASED ON AN AVERAGE ATTENUATION AS SUGGESTED BY GEIGER & HAMME INC. LEGEND: ACCEPTABLE: + A l = 0.1-0.2 TABLE 3.2 123 perfect privacy. In the measured samples of the screen attenuation the r e l a t i o n between A l and subjective impression meets the Acceptable Privacy Condition. Therefore, i n a l l samples, the r e s u l t s obtained meet the expectations for "acceptable" speech privacy established by G r i f f i t h s and evaluated in ANSI - S 3.5 (1969) (see F i g . 2.12 p. 22). 124 3.4 CONCLUSION OF THE SURVEY Having obtained subjective responses and objective measurements i n seven sample open plan o f f i c e s , we now have an accurate and useful data base of general o f f i c e noise l e v e l s and s c r e e n / c e i l i n g acoustical performance. The previous pages described the test procedure and interpreted the test r e s u l t s r e l a t i n g to these findings with approved ac o u s t i c a l guidelines and the e x i s t i n g a c o u s t i c a l problems i n the open plan o f f i c e . A summary of the subjective and objective measurements obtained in t h i s survey are as follows: I. In general the occupant questionnaire suggested that (Table 3.1 p. 73 ) : 1. The physical environment i s 50% acceptable. 2. Screening the sound source i s not successful. 3. Individual work a c t i v i t i e s require an average l e v e l of concentration. 4. On average occupants are s a t i s f i e d . 5. Most employees seek no change i n the present environment. Those who are unhappy seek enclosed o f f i c e s . I I . The objective sound l e v e l measurements provided data on-(Figs. 3.14 to 3.19b p. 89): 1. Present background l e v e l s . 2. T y p i c a l "peak" or maximum noise l e v e l s . 3. The s t a t i s t i c a l d i s t r i b u t i o n of the time v a r i a t i o n i n the noise l e v e l s . I I I . The objective and subjective s c r e e n / c e i l i n g attenua-tion measurements provided data on (Figs. 3.30 to 3.34 p.115 and Table 3.2 p.122): 125 1. Screen/Veiling a c o u s t i c a l performance. 2. Attenuation of sound at s p e c i f i e d distance. An analysis of the above data c o r r e l a t e d these findings with approved a c o u s t i c a l standards. It was found that the general o f f i c e noise levels were spread well above NC 40 and averaged NC 45-50 while background noise l e v e l s of NC 40 are usually recommended as acceptable lev e l s f o r a t y p i c a l active o f f i c e . However, the test data from th i s survey meets the "acceptable" c r i t e r i a for large o f f i c e s as s p e c i f i e d by Keighley. Therefore, i t would seem that background noise l e v e l s of NC 45-50 can s t i l l provide a s u b j e c t i v e l y acceptable noise climate as well as adequate speech privacy. In terms of the s c r e e n / c e i l i n g acoustical performance, 75% of the test samples f e l l below the "standard building c e i l i n g " range (Fig. 3.30 p.115). Screen sample f ) 5»0" x 4*7" from o f f i c e sample No. 3, 595 Burrard, has 23 dB interzone attenuation and f e l l above the "standard building c e i l i n g " . Screen sample h) 4'0" x 5'0" from o f f i c e sample No. 4, 200 G r a n v i l l e , has 20 dB interzone attenuation. Sample e) 5'0" x 5*0" from o f f i c e sample No. 2, 1090 West Pender, has 17 dB attenuation and sample a) 6'0" x 5'0" from o f f i c e sample No. 1, Kapilano 100, has 17 dB interzone attenuation, and a l l three samples f e l l below the "standard building c e i l i n g " . Generally comparing d i f f e r e n t sizes of screen we f i n d that c e i l i n g s are of d i f f e r -ent q u a l i t i e s . Taking into consideration the r e l a t i v e cost of the c e i l i n g , i t i s not recommended to have d i f f e r e n t s i z e s of screens but rather one size such as 5'0" x 5'0" (Table 3.2 p. 122) . 126 The writer advises the consideration of introducing a d d i t i o n a l sound absorbing materials (such as buffers) onto the c e i l i n g i n order that transmitted sound energy i s s u b s t a n t i a l l y reduced. Some of these arrangements are shown in F i g . 2.15 p.35, as tested by Geiger and Hamme laboratory. Fundamental i n t h i s presentation i s the support given by test r e s u l t s - both instrument-measured and judged by the human ear - that acoustical privacy can be achieved i n the open o f f i c e when a l l three elements of the system - good acou s t i c a l c e i l i n g s , sound screens and masking sound - are employed in balance with each other. Neither of these elements meet the c r i t e r i a set. It i s found that where c o n f i d e n t i a l speech privacy i s required screens s h a l l be at least 7'0" high. Beyond that height, the concept of open plan space i s destroyed. Therefore, the other parameters (such as distance from the t a l k e r to the l i s t e n e r , or t h e i r speech d i r e c t i o n ) should be f l e x i b l e and subject to change, since the ultimate assessment of acoustical privacy i s subjective. In summary i t would be correct to say that the a c o u s t i c a l performance of the screens analyzed was adequate for "accept-able" speech privacy conditions. For the r e l a t i o n between A l and Subjective Impression see a guide for speech privacy conditions i n an open, plan o f f i c e (8). It should also be mentioned that the ultimate assessment of the acoustical privacy i s subjective. Completely d i f f e r e n t r e s u l t s can be obtained where the need fo r "excellent" privacy requirements be evaluated at an early stage of planning the design objectives for. each i n d i v i d u a l p r o j e c t . The need for 127 sound masking can be estimated along with other components of the system in making design decisions. If privacy requirements are s u f f i c i e n t l y stringent, i t may be advisable to r e j e c t the open planning concept and to use an enclosed type of o f f i c e . 128 3.5 REFERENCE Keighley, E.G. Geiger and Hamme G r i f f i t h s , J.D, Geiger and Hamme Findings on A c c e p t a b i l i t y C r i t e r i a  For Noise i n Large O f f i c e s : J . Sound V.C. (1970), 11(1) 83-93. a) Test Method PBS-C1 for the d i r e c t measurement of speech privacy p o t e n t i a l (SPP) based on objective judgement. U.S. General Service Administration, August 19, 1972. b) Test Method PBS-C2 for the s u f f i c i e n t v e r i f i c a t i o n of speech privacy p o t e n t i a l based on objective measurements includ i n g methods of functi o n a l interzone attenuation and NC-background. c) Guide for Acoustical Performance  S p e c i f i c a t i o n of an integrated c e i l i n g and background system. U.S. General Service Administration. August, 1972. Rhyming Minimal Contrast...A Simpli- f i e d Diagnostic A r t i c u l a t i o n Test. Journal of Acoustical Society of America, August, 42, No. 1, 1967. The Problem of Acoustical S p e c i f i c a - tions for O f f i c e Landscape C e i l i n g . A yearend status report, Acoustical Laboratories, Ann Arbor, Michigan, D e c , 1971. Warnock, A.C.C. Parkin, P.H., and Humphrey, H.R. Geiger and Hamme Acoustical Privacy i n the Landscape  O f f i c e , FRC 13435, Ottawa. Acoustics Noise and Building Faber and Faber, London, 1969. The Problem of Acoustical Specifica-tions for O f f i c e Landscape C e i l i n g . A yearend status report, Acoustical Laboratories, Ann Arbor, Michigan, D e c , 1971. 8. Hegvold, L.W. Acoustical Design of Open Planned O f f i c e s . CBD 139, July, 1970. 1 2 9 4. CONCLUSIONS AND RECOMMENDATIONS 4.1 SUMMARY OF DATA 4.2 SUMMARY OF CONCLUSIONS 4.3 RECOMMENDATIONS FOR FURTHER STUDY 4.4 CONCLUDING REMARKS 130 4.1 SUMMARY OF DATA This thesis has examined the general o f f i c e noise l e v e l and s c r e e n / c e i l i n g attenuation properties of seven f l o o r lay-outs. This data has been correlated to two approved tests (Acceptable C r i t e r i a for Noise in Large O f f i c e s , E.C. Keighley and Test Method PBS - C . l , U.S. Public Building Service), s e t t i n g acceptable standards for acou s t i c a l performance for the two factors studied as to the general o f f i c e noise l e v e l s and s c r e e n / c e i l i n g acoustical performance. The writer also examined 159 subjective questionnaires, completed by s t a f f on the seven f l o o r s studied. Although speech privacy requirements f e l l within the "acceptable" range of ob j e c t i v e l y s p e c i f i e d standards; subjective, i n d i v i d u a l s a t i s -f a c t i o n was low. One of the major d i s s a t i s f a c t i o n s of personnel was the l e v e l of general o f f i c e noise. Those involved i n pro-f e s s i o n a l or managerial tasks tended to be most d i s s a t i s f i e d with the general noise l e v e l and lack of speech privacy (Table 3.1 p. 73 ). There appears to be a con t r a d i c t i o n in the subjec-t i v e data i n that some complained that the general noise l e v e l made comprehension in telephone conversations d i f f i c u l t - , while others i n adjacent areas complained that private conversations could be too e a s i l y understood by colleagues on the opposite side of the screens. The need for a d d i t i o n a l research i n t h i s area i s c l e a r l y indicated. Not only physical but psychological f a c t o r s are•influencing these responses and need to be examined i n greater depth. Generally there appears a lack of under-standing of people's reaction to open plan o f f i c e . 131 A t h i r d dimension of t h i s study was the administration of G r i f f i t h ' s S i m p l i f i e d Diagnostic A r t i c u l a t i o n Test to obtain yet another measure of actual speech privacy within the work st a t i o n s . This test was given to approximately 50 subjects. The r e s u l t s revealed that generally speech privacy f e l l within the marginal l i m i t s of a c c e p t a b i l i t y . The fa c t remains, how-ever, that the r e s u l t s of t h i s test revealed the same r e s u l t s as the Geiger and Hamme tests used to obtain objective data on noise l e v e l s . The objective r e s u l t s are consistent within this study. In most cases the speech privacy of AI = 0.1 to 0.2 was found to e x i s t (Table 3.2 p.122). It should be noted that a l i m i t a t i o n of th i s study i s the r e l a t i v e l y small sample studied. Therefore, caution i s required in evaluating the data. The conclusions are tentative and require further research to v a l i d a t e t h e i r accuracy. 132 4.2 SUMMARY OF CONCLUSIONS Although the objective data reveals an "acceptable" l e v e l of speech privacy, i t appears that a s i g n i f i c a n t l y higher l e v e l of speech privacy could be achieved by improved f l o o r layout design and better a p p l i c a t i o n of design concepts. Several f a c t o r s deserve serious consideration in achieving speech privacy i n the open plan o f f i c e . The o f f i c e s studied revealed variable attention to these f a c t o r s . They are l i s t e d here as p r a c t i c a l applications f o r further considera-t i o n i n these and other open plan o f f i c e s : (1) Desirable Dimensions: Based on wide experience the desirable dimensions for open o f f i c e building are at least 60 x 120 fe e t . The c r i t i c a l a coustical factor i s r e f l e c t i o n from the walls but other psychological considerations are obviously relevant. (2) Occupant Density and A c t i v i t y Level: It has been found that a minimum of 80-100 people should be considered i n an open o f f i c e area to achieve the necessary a c t i v i t y noise l e v e l . The occupant density depends on the a c t i v i t y l e v e l , but 100 square feet per person i s considered the basic space requirement. (3) Suspended C e i l i n g : This i s the most c r i t i c a l s ingle item i n the open o f f i c e . At present an extensive laboratory i n v e s t i g a t i o n i n i t i a t e d by Geiger and Hamme and continued under the sponsorship of Owens-Corning Fiberglass has developed substantial argu-ments f o r the use of a two-inch thick, TL backed f i b e r g l a s s c e i l i n g product. This product i l l u s t r a t e s absorption c o e f f i c i e n t of .89, at = 45°, which i s the usual angle of incidence. However, other sus-pended c e i l i n g s are providing acceptable a c o u s t i c a l conditions in open o f f i c e areas. (4) Carpeting: This i s required throughout the open o f f i c e areas i n order to absorb airborne noise. In general the a c o u s t i c a l requirements are not s t r i n -gent but the carpet should be thick and be i n s t a l l e d on top of a r e s i l i e n t underlay. (5) Windows/Walls/Curtains: V e r t i c a l r e f l e c t i n g surfaces present problems of h o r i z o n t a l l y r e f l e c t e d sound into the adjacent space. Therefore i t i s necessary to provide absorptive drapery in order to absorb sound incident on the window. A l l these surfaces must be treated with an absorptive material. (6) Screen B a r r i e r s : A basic height of 5 feet should be used f o r normal privacy purposes with larger b a r r i e r s for c o r r i d o r s and conference areas. It i s the writer's observation and f e e l i n g that further study on a v a r i e t y of construction methods and performance q u a l i t i e s of manufactured screens w i l l provide more deta i l e d information on acoustic privacy. (7) O f f i c e Equipment Noise Area: Typewriters and o f f i c e equipment are normally i s o l a t e d by grouping. This avoids problems i n intermittent noise l e v e l s . In c r i t i c a l cases, the noise sources should be located close to screen b a r r i e r s to avoid an acoustical 134 image of the typewriter in the suspended c e i l i n g . Noisy machines should be away from hard walls. (8) Background Masking System: If the background noise created by the air-handling system i s not s u f f i c i e n t l y high, e l e c t r o n i c a l l y c o n t r o l l e d masking noise can be produced with variable background l e v e l and spectrum. A noise generator and amplifier that feeds loud-speakers properly located along the c e i l i n g may be used. (9) Total Privacy Areas: In addition there should be some f u l l y p a r t i t i o n e d rooms fo r communal use to accommodate c o n f i d e n t i a l conferences, etc. A second major conclusion that may be drawn from t h i s study i s that the need for a c o u s t i c a l screening i s determined by the concentration required for the tasks performed and the degree of c o n f i d e n t i a l i t y involved. Generally, d i s t r i b u t i n g work such as processing of information, requires less privacy. The higher the l e v e l of concentration required to complete work, the higher the need for acoustical screening. Thus, those engaged i n highly technical reports, l i k e production work for other users, require greater privacy. Further, those whose work i s of a highly c o n f i d e n t i a l nature need work areas of high speech privacy. These c r i t e r i a should be taken into serious consideration i n the design of an open plan o f f i c e . 135 4.3 RECOMMENDATIONS FOR FURTHER STUDY This study revealed four major areas for further study: A. An evaluation of the r e l a t i o n s h i p between e f f e c t i v e job performance and general o f f i c e noise l e v e l s i s needed. This study has concluded that the higher the requirement for concentration or c o n f i d e n t i a l i t y in job performance, the higher the need for speech privacy. To f a c i l i t a t e accurate, e f f i c i e n t planning and design, c r i t e r i a need to be established to deter-mine "acceptable" noise l e v e l s for tasks of d i f f e r i n g concen-t r a t i o n l e v e l s . What i s an "acceptable" l e v e l of speech privacy for a t y p i s t may be very "unacceptable" for a personnel manager. "Acceptable" noise l e v e l s need to be correlated with job requirements. B. A r e l i a b l e tool f o r evaluating i n t e l l i g i b i l i t y of speech behind screens needs to be developed. G r i f f i t h ' s S i m p l i f i e d Diagnostic A r t i c u l a t i o n Test provides only minimally acceptable data. The p o s s i b i l i t y of error i s too high to r e l y on data r e s u l t s . C. Psychological fac t o r s influencing subjective response to noise l e v e l s need,, to be studied. This variable was not c o n t r o l l e d in t h i s study. D i s s a t i s f a c t i o n may have been r e f l e c t e d by a desire for work space less accessible to other personnel. There are numerous hypotheses that could be drawn and need to be tested to determine what constitutes a sub-j e c t i v e l y "acceptable" noise l e v e l for personnel i n the work s t a t i o n s . D. Perhaps the most c r i t i c a l need to emerge from t h i s 136 study was for s p e c i f i c standards of a c o u s t i c a l performance of the materials used. Designers need to know the ac o u s t i c a l effectiveness of the materials they choose. At the moment guidelines for making such a choice are v i r t u a l l y non-existent. An objective evaluation of material must incorporate the impact of the i n t e r r e l a t i o n s h i p of various materials within the t o t a l plan ( i . e . the influence on the absorptive q u a l i t i e s of the c e i l i n g when l i g h t s are interspersed, when a desk i s d i r e c t l y below the l i g h t , when a typewriter i s next to a draped window, e t c . ) . The complexities and var i a t i o n s are multiple. However, an objective c l a s s i f i c a t i o n of not only materials but the impact of the in t e r p l a y of ac o u s t i c a l elements i s e s s e n t i a l to good acoustical planning and design. 137 4.4 CONCLUDING REMARKS Major considerations in any design are the determination of the need for speech privacy and the subsequent planning to meet those needs. In an open o f f i c e plan, i t has been c l e a r l y indicated that not only can an acceptable l e v e l of speech privacy be obtained for many o f f i c e functions but that with c r e a t i v e and imaginative design and a p p l i c a t i o n , open o f f i c e plans may y i e l d higher l e v e l s of s a t i s f a c t i o n and e f f e c t i v e -ness . S i g n i f i c a n t among the needs of modern o f f i c e personnel are adequate privacy for c e r t a i n types of o f f i c e v/ork, and both physical and psychological s a t i s f a c t i o n with the speech privacy conditions within that environment. It i s hoped that t h i s research e f f o r t contributes to the knowledge base re-garding both the privacy and comfort aspects of the open o f f i c e plan. With these goals i n mind, t h i s study has attempted to compare the speech privacy conditions e x i s t i n g i n ce r t a i n open plan o f f i c e s with both objective measurements of the conditions and subjective reactions to the conditions of speech privacy. As a r e s u l t of the l i t e r a t u r e survey p r a c t i c a l noise c o n t r o l in o f f i c e s should include: (1) C l a s s i f i c a t i o n of the working sta t i o n with respect to noise s e n s i t i v i t y and speech privacy or ac o u s t i c a l screening requirements. (2) Adequate horizontal and v e r t i c a l i n s u l a t i o n between i n d i v i d u a l spaces in order to secure speech privacy so that speech o r i g i n a t i n g i n one o f f i c e should not be i n t e l l i g i b l e i n an adjacent o f f i c e ; 138 and (3) reasonable noise reduction within a p a r t i c u l a r o f f i c e space. Recommended noise l e v e l c r i t e r i a for o f f i c e s have been discussed and found to be of 40 NC on the average. In order to achieve these conditions the acoustic guidelines described should be observed. The factors determining the l e v e l of a c c e p t a b i l i t y of acoustical performance of s p e c i f i c b u i l d i n g elements are i l l u s t r a t e d and found to be of major importance. As a r e s u l t of the noise climate survey i n e x i s t i n g open plan o f f i c e s p r a c t i c a l noise c o n t r o l for o f f i c e s should include: (1) Adequate background noise l e v e l s as s p e c i f i e d i n terms of NC curves which can s t i l l provide a sub-j e c t i v e l y acceptable noise climate as well as adequate speech privacy. A masking noise system which would r a i s e the l e v e l of background noise but would not i n t e r f e r e with normal o f f i c e a c t i v i t i e s could be used to lessen the disturbance from information carrying noise and small machines. (2) The consideration of sound absorptive materials as the noise-reducing e f f e c t of a c o u s t i c a l treatment in the provision of screens and c e i l i n g . The actual lo c a t i o n noise source should be analyzed and dealt with l o c a l l y within work stations i n order to design c r i t e r i a for acceptable speech privacy between work stations and to achieve higher employee p r o d u c t i v i t y . In terms of s c r e e n / c e i l i n g acoustical performance, most of the test samples f e l l below the "standard building c e i l i n g " . In terms of r e l a t i o n between A l and Subjective Impression of 139 Speech Privacy Condition, most screens tested f e l l above acceptable range. Generally taking into consideration d i f f e r e n t q u a l i t i e s of tested c e i l i n g s i t i s not recommended to have d i f f e r e n t sizes of screens, but rather one s i z e such as 5'0" x 5'0". Screen b a r r i e r s providing v i s u a l separation between work stations or c e r t a i n o f f i c e areas need to have only a reasonable amount of sound transmission loss (^STC 20) since spreading noise waves, p a r t i c u l a r l y at low frequencies, w i l l bend around t h e i r edges anyway by the process of d i f f r a c t i o n . S p a t i a l design c r i t e r i a for the ideal open plan o f f i c e s are: - A f l o o r area of 10,000 s q . f t . - Work s t a t i o n spacing not less than 12 f t . with the use of a c o u s t i c a l screens. - The use of a background masking system. S p a t i a l design c r i t e r i a for the least acceptable open plan o f f i c e s are: A f l o o r area of 5,000 s q . f t . (absolute minimum). - Work s t a t i o n spacing not less than 9 f t . with the use of a c o u s t i c a l screens. - No background masking system in use. The open plan o f f i c e i s generally unacceptable i f maximum speech privacy i s required (taken to mean that excellent speech privacy conditions require AI-<•0.02). In t h i s case p r i v a t e -p a r t i t i o n e d o f f i c e s or a board room should be provided. 140 BIBLIOGRAPHY 1. AWAYA, K. 2. BATCHELDER, J.H. 3. BERRANEK, L.L. 4. BERTALANFFY, Ludwig von A New Theory on the"Edge Effect of Sound  Absorbing Panels. ICA 25A2, Budapest, 1971. Sound Absorption of Draperies. Journal of Acoustical Society of America. Vol.42, 1967, Revised Criteria for Noise in Buildings in Noise Control, January, 1957. General System Theory. New York: George Braziller, 1968. 5. BLACK, F.W. Needs of Small Firms. Office Building, Building Research Station current paper, London, 1972. 6. BOUTROS-ATTIA, B. FREEMAN, R., MADSEN, H.S. SIMONSEN, K. Some Recent Developments in Telephone  Receivers, ICA, 19E8, Budapest, 1971. 7. CAVANAUGH, W.Y. FARRELL, W.R. HIRTLE, R.W. WALLERS, B.G. 8. CHERMAYEFF, Serget CHRISTOPHER, Alexander Speech Privacy i n Buildings, The Journal of Acoustical Soc. of Am., Vol.34, No.4, April, 1962. Community and Privacy ed. Anchor Books, Garden City, New York: Doubleday & Co. 1965. 9. CHRISTOFFER, R.. 10. C0RS0, Dr. J.F. A Pattern Language for the Mental Health  F a c i l i t i e s , A thesis submitted for the degree of M.ARCH., University of Oregon, July, 1971. Age & Sex Differences in Pure-Tone  Thresholds from 18 to 65 years. ICA, H23, Copenhagen 21-28, August, 1962. 11. COWAN, P., FINE, D., IRELAND, J., JUDON, C., MERCER, D., SEARS, A. 12. DAVIS, G. The Office, A Facet of Urban Growth Heinmann Educational Books Ltd., London, 1969, People in the Work-Place, published in the Journal of the BRAB Building Research Institute, Vol.9, No.2, IV/VI, 1972. 141 13. DAVIS, G. 14. DAVIS, G. 15. DAVIS, G. 16. DAVIS, G. Using Interviews of Present Office Workers in Planning New Offices, Paper from the Proceeding EDRA 3/AR.8 TEAG. 1972 Creating an Effective Environment, presented to Department of Environment Ottawa. TEAG, 1973, Vancouver. Photographic Methods of Research on Behaviour in the Human Milieu: New Developments and Critique. TEAG The Environmental Analysis  Group, Blacksburg, Va., 1973. Creating an Effective Environment, presented to the Department of Environment - Ottawa. TEAG The Environmental Analysis Group, September, 1973. 17. DAVIS, G. Applying a Planned Design Process and Specific Research to the Planning of Offices. TEAG The Environmental Analysis Group, March 1974. 18. DENES, P.B. On Line Computing in Speech Research (Bell Telephone Laboratories) ICA; A23; Liege 7-14 September, 1965. 19. DUFFY, Frank Office Landscaping. London, England: Anbar Publication, 1969. 20. DUNN, H.K. WHITE, S.D. Stat i s t i c a l Measurements on Conversational  Speech (Bell Lab.) Journal of the Acous. Soc. of Am. 11.278, 1940. 21. EDBERG, G. The Use of Light as an Aesthetic Component  in Design: A Proposal for a Method, C L E . Study Group A, Conference, 1970. 22. FLANAGAN, J.L. 23. FRENCH, N.R. STEINBERG, J.C. Recent Studies i n Speech Research at Bell Telephone Laboratories (II). I.C.A., A22, Liege 7-14th September, 1965. Factors Governing the I n t e l l i g i b i l i t y of Speech  Sounds. The Journal of the Acoustical Society of America, V.19, No.l, January, 1947. 24. GEIGER & HAMME The Problem of Acoustical Specifications for  Office Landscape Ceiling. A year end status report, Ann Arbor, Michigan, U.S.A. 142 25. GOFFMAN, E. 26. HALL, Edward T. 27. HAINE, Richard HUGGINS, Don 28. HARRIS, J.D. 29. HAWKES, D STIBBS, R. 30. HESSELGREN, S. 31. HIRSH, I.J. 32. HIRSH, I.J. 33. HOOGENDOOVUK, B. 34. HOPKINSON, R.G. 35. HOPKINSON, R.G. COLLINS, J.B. 36. HOUSE, A.S. WILLIAMS, E. HECKER, M.H.L. KRYTER, K.D. Behaviour in Public Places. Collier-MacMillan Ltd., London, 1963. The Hidden Dimension. A Doubleday Anchor Book, New York, 1966. "Acoustic in the Open-Plan" from Office Design Press International Business Inc. Copyright, 1968. Pure-Tone Acuity and the I n t e l l i g i b i l i t y of  Everyday Speech. The Journal of the Acoustical Society of America, V37, No.5, May, 1965. The Environmental Evaluation of Buildings, The Working Paper of the Centre for Land Use and Built Form Studies i n the University of Cambridge,(pp. 15, 27, 28, 29, 34, 18, 19, 20.) The Language of Architecture, Student Literature, Lund, Sweden, 1969. I n t e l l i g i b i l i t y of Different Speech Materials Journal of the Acoustical Society of America. Vol. 26, No. 4, July, 1954 I(3)C. B(i) The Third Annual Fairey Lecture: Acoustical  Bases of Speech Perception. Journal of Sound Vibration, 1973 27(1), 111-122. How to Cope with Noise in Open-Plan Offices, Building Research and Practice, July/August, 1973. Architectural Physics - Lighting, London: Her Majesty's Stationery Officer, 1963. The Ergonomics of Lightings, MacDonald,Technical and Scientific, London, 1970. Articulation - Testing Methods: Consonantal  Differentiation with a Closed Response Set. Journal of the Acoustical Society of America, Vol. 37, No.l, January, 1965. 143 37. Illumination Engineering Society 38. I.E.S. Code 39. JONES, CHRISTOPHER &+TH0RNLEY 40. JOEDICKE, T. 41. KALF, L.C. 42. KEIGHLEY, E.C. (1) (2) 43. KOSTIC, D.J. 44. KRYTER, K.D. 45. KRYTER, K.D. 46. LANGDON, F.J. 47. LARSON, Leslie 48. LIEBERMAN, P. 49. LONEY, W. Evaluation of Discomfort Glare: The IES Glare Index System for A r t i f i c i a l Lighting Installations, IES Technical Report, No.10, The Society of London, 1967. Recommendations for Good Interior Lighting Illuminating Engineering Society, London, 1969. Conference on Design Methods, MacMillan, 1963 Office Buildings: Crosby Lockwood, London, 1964. Creative Light, Philips Technical Library, London, Copywright, 1971. The Determination of Acceptability Criteria  for Office Noise, J. Sound Vib. (1966) 4(1) 73-87. Acceptability Criteria for Noise in Large Offices J.Sound Vib. (1970) 11(1), 83-93. Relation Between Acoustic Elements of Speech  Sounds and Phonetic Perception. ICA, B44, Liege 7-14 September, 1965. Methods for the Calculation and Use of the  Articulation Index. Journal of the Acoustical Society of America, Vol.34, 1962, pp 1689-1697. The Effects of Noise on Man, Academic Press, New York, 1970, Ch.2 "A Study of Annoyance", Building Science, Vol. I, 1965. Lighting and Its Design, Whitney Library of Design, New York, Copywright, 1964. Some Acoustic Correlates of Word Stress i n  American English. Journal of the Acoustical Society of America, Vol.32, No.4, Ap r i l , 1960. Effective of Cavity Absorption on the Sound  Transmission loss of Steel-Stud Gypsum Wall  Board Paritions. Journal of the Acoustical Society of America. Vol. 49, 1971. 50. LOWE, A.W. The Effectiveness of Barriers Under Extended Ceilings. From Inter-Noise 72 Proceedings. 144 51. LYNCH, K. 52. LYNES, J.A. 53. MAEKAWA, Zyun-lti 54. MEYER, A.F. 55. MICHELSON, W. 56. MILLBANK, H.O. LYNN, J.H. 57. MILLER, G.A. 58. MILLER, D.C. 59. MOREIRA, N.M. BRYAN, M.E. 60. MORELAND, J.B. MUSA, R.S. 61. PARKIN, P.H. HUMPHREYS, H.R. 62. PETERSON, P.G. GROSS, E.E. 63. PIRN, Rein 64. PLANAS, R.E. The Image of the City. Cambridge, Mass. M.I.T. Press and Harvard University Press. Lightness, Colour and Constancy in Lighting  Design, IES, Lighting Research and Technology, Vol. 3, No. 1, 1971, London. Noise Reduction by Screens. ICA, F l , Leige 7-14 September, 1965. The Need for Standard on Noise: Journal of Acoustical Society of America. Vol. 51, No.3, 1972 (Part 1). Man and His Urban Environment: A Sociological  Approach. Addison-Wesley, 1970. Estimation of Air Conditioning Loads in Sherrat A.F.C. (Ed) Air Consitioning System Design for Buildings, Elsevier, London, 1969. Speech and Communication: The Journal of the Acoustical Society of America, Vol. 30, No.5, May, 1958. Handbook of Research Design and Social Measurement. New York, David McKay & Co. Inc., 1964. Noise Annoyance Susceptibility. Journal of Acoustical Society of America (1972) 21(4) 449-462. The Performance of Acoustic Barriers From Inter-Noise 72 Proceedings. Acoustics Noise and Buildings. Faber and Faber, London, 1958. Handbook of Noise Measurement. General Radio Co., West Concord, Mass., 1963. "Acoustical Variables in Open Planning". The Journal of the Acoustical Society of America, Vol. 49, No.5 (Part 1) 1339-1345, Mary, 1971. Integrated Planning Concept Imperative for Office Landscaping. Paper by President of Quiqborner Team, Inc. Milburn, N.J. 145 65. POTTER, R.K. STEINBERG, J.C. 66. PROSHANSKY, H.M. HELSON, Wm. H. RIVLIN, L.G. Q 67. PRICE, A.J. 68. ROSENBLITH, W.A. STEVENS, K.N. 69. SAKAI, T. THORNE, E. 70. SCHOEFFLER, M.S. 71. SCHROEDER, M.R. 72. SHUTTLEWORTH, G. 73. SLOAN, S.A. 74. SOMMER, Robert 75. SOTTSASS, E. Jr. 76. SUMBY, W.H. POLLACK, I. Toward the Specification of Speech: The Journal of the Acoustical Society of America, Vol.22, No.6, November, 1950. Environmental Psychology: Man and His Physical  Setting: New York: Holt, Rinehart & Winston, Inc., 1970. A Community Noise Survey of Greater Vancouver, U.B.C. School of Architecture, 1971. Handbook of Acoustic Noise Control. Vol. II: Noise and Man. W.A.D.C. Technical Report S2-204. ^ New Instruments and Methods for Speech Analysis Theory for Psycho-Physical Learning: Journal of Acoustical Society of America, Vol.37, No.6, June, 1965. Recent Studies in Speech Research at Bell Telephone Laboratories (I). ICA A21, Liege 7-14, September, 1965. Programming New Office Accommodation for Work  and People: E.P.A. Working Paper, Crowborough Sussex, U.K., 1974. Translating Psycho-Social Criteria into  Design Determinations: E.D.R.A. 3 April 8 Personal Space. Englewood C l i f f s , New Jersey: Prentice-Hall, Inc., 1969. "UFFICI" (From the Traditional Office to the Open-Plan Office). Published by Direzione Relazioni Culturali Disegno Industrial-Pubblicita' of Ol i v e t t i , Milano, 1973. Visual Contribution to Speech I n t e l l i g i b i l i t y  i n Noise. Journal of Acoustical Society of America, Vol.26, 1954, pp. 212-215. 77. TUMARKIN, A. A Biologist Looks at Psycho-Acoustics. Journal of Sound and Vibration (1972) 21(1) 115-126. 146 78. U.S. GYPSUM BOARD 79. VOIERS, W.D. 80. WALKER, R.A. 81. WARNOCK, A.C.C. HENNING, D.N. NORTHWOOD, T.D. 82. WARNOCK, A.C.C. 83. WEBB, C.G. 84. WILLIAMS, C. 85. YOUNG, R.W. 86. ZWICKER, E. 87. 88. Sound Control Construction: Chicago, Copyright, 1972, Chapter III. Perceptual Bases of Speaker Identity: The Journal of the Acoustical Society of America, Vol.36, No.6, June, 1964. Office Acoustics - Effect of Background Noise Applied Acoustics (2), 1969. "Acoustic Survey of an Open-Plan Landscaped  Office", D.B.R. Internal Report No. 400 for N.R.C. of Canada, Ottawa, 1972. Acoustical Privacy in the Landscapped Office Journal of the Acoustical Society of America Vol.53, No.6, June, 1973, pp. 1535-1543. Thermal Comforts and Effective Temperature C L E . Conference on sunlighting in buildings. Newcastle-Upon-Tyne, 1965. Aural Speaker Recognition and Speech Communication  System Evaluation. ICA, 21C3, Budapest, 1971. Revision of the Speech-Privacy Calculation The Journal of the Acoustical Society of America, Vol. 37, No.l, 1965. "Ein Verfahren Zur Berechnung den Lautstarke" Acoustica, Vol. 10, No.l, 1960, pp. 304-308. Office Equipment and Methods. The MacLean-Hunter Publication for Administrative Executives Reader Survey, 481 University Avenue, Toronto, M5W 1A7. The Telephone a Hundred Years Later. In Search. A magazine published by the Department of Communication Government of Canada, Summer, 1974. 147 UNPUBLISHED WORK 1. DUFFY, Francis 2. DUFFY, Francis C. 3. PETTIT, Nicholas B. 4. RUYS, Theodorus "Work, Organisation, Behaviour and Office  Buildings". Unpublished Paper, University of California, Berkeley, 1968. "Office Interiors and Organizations" A Draft of a Dissertation Presented to the Faculty of Princenton University in Candidacy for the Degree of Doctor of Philosophy, 1973. "Factors Contributing to Utilization of Living  Space in Urban Communal Dwellings" A Thesis presented to the Faculty of Graduate School of Human Behavior, United States International University, 1971. "Windowless Offices" A Thesis submitted in partial fulfillment of the requirements for the Degree of Master of Architecture, University of Washington, 1970. 5. Environmental Planning Assistance. E.P.A. Working Papers, Snaepbrok Lordswell Lane Crowborough, Sussex, 1973. APPENDIX A . l THE QUESTIONNAIRE SAMPLE EVALUATION OF OPEN OFFICE ENVIRONMENT ( T h e f o l l o w i n g Q u e s t i o n n a i r e I s f o r U n i v e r s i t y r e s e a r c h . We v o u l d be v e r y g r a t e f u l f o r a f e u m i n u t e s o f y o u r t i m e t o c o m p l e t e I t and cheek c r n e p e r e a c h t a s k . ) 1. Department 2. J o b T i t l e 3. What t y p e o f apace do y o u o c c u p y ? Open A r e a P r i v a t e O f f i c e ( ) ( ) 4 . L o c u t i o n : F a c i n g Window F a c i n g c e n t r a l c o r e o r v a i l ( ) ( ) 5. M a t u r e o f y o u r v o r k ? ( P l e a a e c h e c k one) c l e r i c a l - no t y p i n g ( ) T e c h n i c a l ( ) c l e r i c a l - v i t h t y p i n g ( ) E x e c u t i v e ( > p r o f e s s i o n a l ( ) O t h e r ( ) 6 . W h i c h o f t h e f o l l o v l n g a c t i v i t i e s do y o u do most d u r i n g * d a y ? T y p i n g ( ) Kc»d ( ) On t e l e p h o n e ( ) W r i t e ( ) F i l i n g ( ) D r a f t i n g ( ) D i c t a t i o n ( ) D e s i g n ( ) M e e t i n g s ( ) O t h e r 7. Hov v o u l d y o u d e s c r i b e n o i s e s o u t s i d e the b u i l d i n g ? v e r y v e r y q u i e t l e s s t h a n n o m i l a b o u t n o r m a l n o i s y n o i s y ( ) . ( ) ( ) ( ) ( ) 8. t l o v v o u l d y o u d e s c r i b e t h e g e n e r a l o f f i c e n o i s e ? v e r y b a d somewhat bad a c c e p t a b l e q u i e t v e r y q u i e t ( ) ( ) ( ) ( > ( ) 9 . W h i c h k i n d o f o f f i c e d i d y o u o c c u p y b e f o r e t h e p r e s e n t o n e ? o p e n a r e a p r i v a t e o f f i c e ( ) < ) 10. Hov d o e s y o u r p r e s e n t o f f i c e compare w i t h y o u r fo rmer o f f i c e ? much s o o e v h a t l i t t l e o r somewhat o u c h b e t t e r b e t t e r n o d i f f e r e n c e w o r s e v o r s e ( ) ( ) ( ) ( ) ( ) 1 1 . H o v i m p o r t a n t i s p r i v a c y i n y o u r s p e c i f i c t y p e o f v o r k ? v e r y somewhat n o t v e r y n o t i m p o r t a n t i m p o r t a n t i m p o r t a n t i m p o r t a n t i m p o r t a n t V i s u a l P r i v a c y : ( ) ( ) ( ) ( ) ( ) N o i s e P r i v a c y : ( ) ( ) ( ) < ) c ; 12. Hov much v i s u a l p r i v a c y do y o u p r e f e r f o r t h e f o l l o v l n g a ' t a s k s ? Ho Some Does n o t A l o t o f T o t a l T e l e p h o n e c o n v e r s a t i o n P r i v a c y ( ) P r i v a c y ( ) M a t t e r ( ) P r i v a c y ( ) P r i v a c y ( ) W o r k i n g b y y o u r s e l f • t y o u r v o r k p l a c e ( ) (J> < ) ( ) ( ) S m a l l c o n f e r e n c e o f m e e t i n g a t y o u r w o r k p l a c e ( ) ( ) ( ) ( ) ( ) 13. H o v much p r i v a c y f r o m b e i n g o v e r h e a r d d o ' y o u p r e f e r f o r t h e t o l l e v l n i t „ v , , No Some Does n o t A l o t o f T o t a l P r i v a c y P r i v a c y M a t t e r P r i v a c y P r i v a c y T e l e p h o n e c o n v e r s a t i o n ( ) ( ) ( ) ( ) ( ) W o r k i n g b y y o u r s e l f a t y o u r v o r k p l a c e ( > ( > ( ) ( ) ( ) S m a l l c o n f e r e n c e o f t w e t l n g a t y o u r v o r k p l a c e ( ) ( ) < ) •(') < ) 1*. Hov much p r i v a c y f r o m n o i s e s o u t s i d e y o u r w o r k p l a c e d o y o u p r e f e r ? Ro Some Does n o t A l o t of" T o t a l P r i v a c y P r i v a c y M a t t e r P r i v a c y P r i v a c y T e l e p h o n e c o n v e r s a t i o n ( ) ( ) < > ( ) ( > W o r k i n g b y y o u r s e l f « t y o u r v o r k p l a c e ( ) ( ) ( ) ( ) ( ) S m a l l c o n f e r e n c e o f m e e t i n g a t y o u r v o r k p l a c e ( ) ( ) ( ) ( ) ( ) 13. B o v do y o u f i n d t h e g e n e r a l l i g h t i n g c o n d i t i o n s ? v e r y somewhat q u i t e t o o p o o r i n s u f f i c i e n t s u f f i c i e n t b r i g h t b r i e h t ( > ( ) ( ) ( ) ( ) 1 6 . How do y o u f i n d g e n e r a l c o l o u r scheme ( I n c l u d i n g c a r p e t s , s c r e e n s , f u r n i t u r e a n d w a l l ) ? somewhat a t t r a c t i v e a t t r a c t i v e . m e d i o c r e u n a t t r a c t i v e u g l y (; (> () () () 1 7 . How do y o u f i n d g e n e r a l e n v i r o n m e n t c o n d i t i o n s ? P o o r F a i r A c c e p t a b l e Cood E x c e l l e n t A i r C o n d i t i o n i n g ( ) ( ) ( ) ( ) ( ) B u i l d i n g H e a t i n g ( ) < ) ( ) ( ) ( ) S u n h e a t i n g f r o m w i n d o w s ( ) ( ) ( ) ( ) ( ) 1 8 . I f y o u f e e l t h e new o f f i c e l a w o r s e t h a n y o u r p r e v i o u s one w i t h r e g a r d t o a n y o f t h e above a s p e c t s , what do y o u t h i n k , s h o u l d be done? M o r a s c r e e n d i v i d e r s ( ) R e l o c a t e y o u r w o r k s t a t i o n ( ) L a r g e r w o r k s t a t i o n ( ) C o n f i e n t l s l O f f i c e ( ) O t h e r • 1 9 . O v e r a l l , w h a t w o u l d y o u s a y y o u l i k e mos t a b o u t t h e o p e n p l a n o f f i c e ? > - r e e f f e c t i v e c o — . u n l c a t l o n ( ) I n p r o v e d g e n e r a l c l i m a t e ( ) M o d e r n o f f i c e e q u i p m e n t ( ) O t h e r _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ ( c a r p e t s , p l a n t s , e t c ) . 2 0 . O v e r e l l . v h » t d ? y o u l i V . e l » s s t I t ? T o o p u b l i c and l o c k o f v i s u a l p r i v a c y ( ) T e m p e r a t u r e t o o h o t ( ) N o i s e l e v e l t o o h i g h ( ) O t h e r _ _ _ _ _ _ _ _ _ _ _ _ U n s a t i s f a c t o r y l i g h t i n g ( ) T o o much t r a f f i c and l a c k o f s p a c e ( ) 2 1 . E x t r a n o t e s y o u w i s h t o moke r e g a r d i n g y o u r e x p e r i e n c e w i t h w o r k i n g I n a n o p e n a r e a o f f i c e - a d v a n t a g e s , d i s a d v a n t a g e s , e t c . w o u l d be g r e a t l y a p p r e c i a t e d . O APPENDIX A.2 THE ANALYSIS OF DATA N o t e : Q u e s t i o n n a i r e s A n e v e r s * T h r W r i t e r ' s Comment -THE A N A L Y S I S OF DATA O f f i c e 6 A d d r e s s : K A P i U i l o | « o • l£-vfeiHGOUVSPnt F l o o r : "J-rooWP T « . t o / < T o t a l Nuraber o f Q u e s t i o n n a i r e s : 3 9 — ' T o t a l A n s w e r s : 3 4 £7*7'/. THE P H Y S I C A L ENVIRONMENT OF THE OBSERVER a') T e c h n i c a l I n f o r m a t i o n - S i z e & Shape o f F l o o r P l a n l o o - o jf loe-o" - N e t F l o o r A r e a P e r P e r s o n {'ZoZcT - C e l l i n g H e i g h t V ' - o ' • b) Location of Work S t a t i o n * Facing VlmJvw * F a c i n g C e n t r a l C o r e +3.4'/. e ) The C e n e r a l N o i s e L e v e l * How w o u l d y o u D e s c r i b e N o i s e s O u t s i d e t h e B u i l d i n g V e r y Q u i e t yo/. L e a s T h e n N o r m a l \cy. A b o u t N o r m a l lty< N o i s y \cy. V e r y N o i s y * How w o u l d y o u D e s c r i b e t h e C e n e r a l O f f i c e N o i s e V e r y Q u i e t Q u i e t A c c e p t a b l e t>>.»v/ Somewhat Bad 3<U/< V e r y B a d 2 V / *How Do Y o u F i n d C e n e r a l E n v i r o n m e n t C o n d i t i o n s ? P o o r F a i r A c c e p t a b l e Cood E x c e l l e n t A i r C o n d i t i o n i n g <S.u'/. 2>Z. Ao.1. 2o. Z 5. 2 B u i l d i n g H e a t 6-7/ 2-5.1 + 5 ^ 20. "^^ Sun H e a t i n g f r o m Windows SO 2-S- 4^7 2.4.1* 1*{>'/t I s T h e r e Any W h i t e N o i s e ? T e s . No X ANNOYANCE L E V E L OF NOISE a) C h a r a c t e r o f t h e N o i s e i Sound R e f l e c t i o n - C e n e r a l R e f l e c t i o n ^ i*W**M-rs. - ,Loc-£ lun - L i g h t i n g Hum l^trT u u n c / W C b) O f f i c e A c t i v i t i e s t Sound Impac t • N a t u r e o f y o u r w o r k C l e r i c a l - no t y p i n g C l e r i c a l - w i t h t y p i n g IC-7/, P r o f e s s i o n a l HVf/. T e c h n i c a l I*-?/. E x e c u t i v e v O t h e r • W h i c h o f t h e F o l l o w i n g A c t i v i t i e s d o y o u do m o s t D u r i n g s Day T y p i n g r\>-9/, On T e l e p h o n e F i l i n g D i c t a t i o n M e e t i n g s Read W r l t e £ D r a f t i n g -5.}/ ^ c/: D e s i g n c ) I n d i v i d u a l Work A c t i v i t i e s * Hov Much V i s u a l P r i v a c y do y o u P r e f e r f o r t h e F o l l o w i n g T a s k s ? Ho Some Does Hot A L o t . o f T o t a l P r i v a c y P r i v a c y M a t t e r P r i v a c y P r i v a c y T e l e p h o n e C o n v e r s a t i o n C,2'/ Zo.$T 2o.7 2*2. •7.7. W o r k i n g b y Y o u r s e l f a t y o u r Work P l a c e 1 C. AC.l tc.7 S m a l l C o n f e r e n c e o f M e e t i n g a t y o u r Work P l a c e 9-4'/' » Hov Much P r i v a c y f rom b e i n g O v e r h e a r d do y o u P r e f e r T a s k s ? f o r t h a F o l l o w i n g K o P r i v a c y Soma P r i v a c y Does No t M a t t e r A L o t o f P r i v a c y T o t a l P r i v a c y T e l e p h o n e C o n v e r s a t i o n 4.7 *7 7?-7 7.Z W o r k i n g b y T o u r s e l f a t T o u r Work P l a c e / 4.3- I C V 1o-i I8.Z S m a l l C o n f e r e n c e o f M e e t i n g a t T o u r Work P l a c e 0- zz. z/ * B o v M u c h P r i v a c y f rom N o i s e s O u t s i d e y o u r Work P l a c e do y o u P r e f e r ? No P r i v a c y Some P r i v a c y Does R o t M a t t e r A L o t o f P r i v a c y T o t a l P r i v a c y T e l e p h o n e C o n v e r s a t i o n chf, ? f . 5 \11 W o r k i n g b y T o u r s e l f a t T o u r Work P l a c e ?o .O 40.0 ar.7 S m a l l C o n f e r e n c e o f M e e t i n g a t T o u r Work o. HQ u-7 P l a c e L O C A T I O N OF SOUND a ) O f f i c e M a c h i n e - T y p e o f a S o u r c e ~&jcc*if-f HACJUffi - L o c a t i o n o f a S o u r c e C l i q u e ' - c t * - S e d u c t i o n o f N o i s e T\/j*mAX> • 1>) S p e e c h I n t e r f e r e n c e • T h a A v e r a g e o f t h e S o u n d P r e s s u r e L a v a l o f t h e N o i s e feeuT-iA.1. c ) W a l l T r e a t m e n t a n d A b s o r p t i o n . - W a l l M a t e r i a l V l u y C 4 w c t ^ * c r - * J * o 4 T c < U -- C e l l i n g M a t e r i a l « > < _ > . > r e t t - Window A r e a Ht>y. - F l o o r M a t e r i a l C » » « . t - c " T - D e n s i t y o f S c r e e n H a r r i e r s A<Ci>-»«A*-THE E X P E R I E N C E OF THE OBSERVERS « ) L e n g t h o f Employment - Bow many p e o p l e w e r e e m p l o y e d s i n c e t h a d e p a r t m e n t moved i n t o - t h i s b u i l d i n g C*'f. - ( o r ) be fo . - e t h a move i n t o t h i s b u i l d i n g Z*'/, j * W h i c h k i n d o f o f f i c e d i d y o u o c c u p y b e f o r e t h a P r e s e n t One? j Open A r e a P r i v a t e O f f i c e ! * How d o e s y o u r p r e s e n t o f f i c e c o m p a r e v l t h y o u r F o r m e r O f f i c e ? | Much Somewhat L i t t l e o r S o o e v h a t M u c h B e t t e r B e t t e r No D i f f e r e n c e Worae W o r s e | 3o/. 2V i/ . 2c/ b/ <*'/> * Hov I m p o r t a n t t s P r i v a c y i n y o u r S p e c i f i c T y p e o f Work? V e r y Somewhat N o t V e K o t I m p o r t a n t I m p o r t a n t I m p o r t a n t I m p o r t a n t I m p o r t a n t V i s u a l P r i v a c y : \C.l/ t O . »..<... n-J / 6.7 c.vy N o i s e P r i v a c y : 3*,. - ^ . ^ 2 £ > b ) G e n e r a l I n t e r i o r I m p r e s s i o n • B o v do y o u f i n d t h e G e n e r a l L i g h t i n g C o n d i t i o n s ? V e r y Somewhat Q u i t e T o o P o o r I n s u f f i c i e n t S u f f i c i e n t B r i g h t B r i g h t O . O . J * i . i / . c / , • B o v do y o u f i n d g e n e r a l C o l o u r S c h c e * ( I n c l u d i n g c a r p e t s , s c r e e n s , f u r n i t u r e and w a l l ) ? Somewhat A t t i « r t l v « A t t r a c t i v e M e d i o c r e U n a t t r a c t i v e V e l y . f ? . . 7 / '.•<:/ Z-..'./. t> . C) C e n t r a l E m p l o y e e ' s E x p e c t a t i o n • I f y o u f e e l t h e new o f f i c e i s v o r s e t h s n y o u r p r e v i o u s one v l t h r e g a r d t o any o f t h e above a s p e c t s , v h a t do y o u t h i n k s h o u l d be . d o n e ? M o r e S c r e e n D i v i d e r s C-7 '/• R e l o c a t e T o u r Work S t a t i o n L a r g e r Work S t a t i o n c . 7 / • C o n f i d e n t i a l O f f i c e , O t h e r ^ » O v e r a l l , v h a t v o u l d y o u s a y y o u l i k e m o s t a b o u t t h e o p e n p l a n o f f i c e ? M o r e E f f e c t i v e C o m a u n l c a t l o n . f t . -7/- I m p r o v e d C c n e r a l C l i m a t e /"<"•/ M o d e m O f f i c e E q u i p m e n t ti.-7 O t h e r i_ ( c a r p e t s , p l a n t s , e t c ) . Ik. n r v p i . i/t> /> , .> / O v e r a l l , v h a t do y o u l i k e l e a s t a b o u t i t ? T o o P u b l i c & L a c k o f V i s u a l P r i v a c y T e m p e r a t u r e T o o Hot N o i s e L e v e l T o o Hlg ' . i (V 4 O t h e r p. U n s a t i s f a c t o r y L i g h t i n g c_ Too Much T r a f f i c & L a c k o f S p a c e T A 8 > L £ » - 4 -R o t e : Q u e s t i o n n a i r e s A n s w e r s * The W r i t e r ' s Comment -THE A N A L Y S I S OF DATA O f f i c e & A d d r e s s : \0<)o 10 . f &+iDe-rt. F l o o r : Tuit>_i> _ T o t a l Number o f Q u e s t i o n n a i r e s : 2<5 ' * ! O o / > T o t a l A n s w e r s : j £ to/' THE P H Y S I C A L ENVIRONMENT OF THE OBSERVER a ) T e c h n i c a l I n f o r m a t i o n - S i r e t Shape o f F l o o r P l a n fSa - d'< - o'' - N e t F l o o r A r e a P a r P e r s o n fjc'**r - C a l l i n g H e i g h t V - o ' b) L o c a t i o n o f Work S t a t i o n * F a c i n g window * F a c i n g C e n t r a l C o r a c ) The C e n e r a l N o i s e L e v e l * How w o u l d y o u D e s c r i b e N o i s e s O u t s i d e t h e B u i l d i n g V e r y Q u l s t ^ / L e s s T h a n N o r m a l (j A b o u t N o r m a l N o i s y O . V e r y N o i s y o . Br-/ * How w o u l d y o u D e s c r i b e t h e C e n e r a l O f f i c e N o i s e V e r y Q u i e t , d Q u i e t ^ 0 A c c e p t a b l e Somewhat Bad V e r y Bad < • < . / . • H o w Do T o u F i n d C e n e r a l E n v i r o n m e n t C o n d i t i o n s ? F a i r A c c e p t a b l e C o o d E x c e l l e n t z - 7 o Co. © j ( S O O/, P o o r A i r C o n d i t i o n i n g 2.>/# B u i l d i n g H e a t / ' S u n H e a t i n g f r o m Windows ^ . 2 l a T h e r e A n y W h i t e N o i s e ? T e s . No X ANNOYANCE L E V E L OF N O I S E a ) C h a r a c t e r o f t h e N o i s e t Sound R e f l e c t i o n - C e n e r a l R e f l e c t i o n F C < . i u C<»<T,*c : -v . - L o c a t i o n o f \j- O A ^ A A I U ' > • « / ; > > » . l/__f— - L i g h t i n g Hum ^XJMC b> O f f i c e A c t i v i t i e s 4 Sound I m p a c t • N a t u r e o f y o u r w o r k C l e r i c a l - no t y p i n g o C l e r i c a l - w i t h t y p i n g O P r o f e s s i o n a l ' -7 T e c h n i c a l &>3 E x e c u t i v e O O t h e r O • W h i c h o f t h e F o l l o w i n g A c t i v i t i e s d o y o u d o m o s t D u r i n g a Day T y p i n g On T e l e p h o n e F i l i n g D i c t a t i o n • . e> o M e e t i n g s O Read S". <* W r i t e < s - 7 . D r a f t i n g / g D e s i g n e ) I n d i v i d u a l Work A c t i v i t i e s • How M u c h V l B u a l P r i v a c y do y o u P r e f e r f o r t h e F o l l o w i n g T a s k s ? Ho Some Does H o t A L o t o f T o t a l P r i v a c y P r i v a c y M a t t e r P r i v a c y P r i v a c y T e l e p h o n e C o n v e r s a t i o n O 4-5 4.8 T o <? W o r k i n g by Y o u r s e l f a t y o u r Work P l a c e 6 S,"7 4.5 £.7 6/7 S n a i l C o n f e r e n c e o f M e e t i n g a t y o u r Work Q y f . g . - > 2 _ C ^r/, P l a c e / ' * How Much P r i v a c y from b e i n g O v e r h e a r d do y o u P r e f e r f o r t h e F o l l o w i n g T a s k s ? tto Some Does Not A L o t o f T o t a l P r i v a c y P r i v a c y M a t t e r P r i v a c y P r i v a c y T e l e p h o n e C o n v e r « « t l ~ . p / ? C , 7 £>-3 1C W o r k i n g by Y o u r s e l f a t Y o u r Work P l a c e /0.7 2<^,2 Z .1 / O S " S s s l l C o n f e r e n c e o f M e e t i n g a t Y o u r Work P l a c e XZ.Z, 7.C£ Ct 11.7/ • How Much P r i v a c y f r o o N o i s e s O u t s i d e y o u r Work P l a c e do y o u P r e f e r ? No Some Does No t A L o t o f T o t a l T e l e p h o n e C o n v e r s a t i o n ^ ' / ^ ^ • r > W o r k i n g b y Y o u r s e l f 1 l . " 7 a t Y o u r Work P l a c e S m a l l C o n f e r e n c e o f M e e t i n g a t Y o u r Work P l a c e H a t t e r P r i v a c y P r i v a c y 7 ? Zi.c 0. fj to . S" c c L O C A T I O N OF SOUND a ) O f f i c e M a c h i n e - T y p e o f a S o u r c e fcfefSoc- J U A C — . . - L o c a t i o n o f a S o u r c e O p ^ t ; A R F A - R e d u c t i o n o f N o i s e O o f ' - o C / S V y * b) S p e e c h I n t e r f e r e n c e • • - The A v e r a g e o f t h e Sound P r e s s u r e L e v e l . o f t h e N o i s e U w r i l - A U e ) W a l l T r e a t m e n t and A b s o r p t i o n - W a l l M a t e r i a l - C a l l i n g M a t e r i a l - Window A r e a "rWiirr - F l o o r M a t e r i a l - D e n s i t y o f S c r e e n B a r r i e r s " Uzv>i<jM THE E X P E R I E N C E OF THE OBSERVERS • ) L e n g t h o f Employment - How many p e o p l e we re e m p l o y e d s i n c e t h e d e p a r t m e n t _ moved I n t o t h i s b u i l d i n g - ( o r ) b e f o r e t h e move i n t o t h i s b u i l d i n g • • W h i c h k i n d o f o f f i c e d i d y o u o c c u p y b e f o r e t h e P r e s e n t One? Open A r e a P r i v a t e O f f i c e Co/ 2 * / * Row d o e s y o u r p r e s e n t o f f i c e compare w i t h y o u r F o r m e r O f f i c e ? Much Somewhat L i t t l e o r Somewhat M u c h B e t t e r B e t t e r No D i f f e r e n c e Worse W o r s e * B o v i m p o r t a n t i a P r i v a c y i n y o u r S p e c i f i c Type o f Work? V e r y Somewhat N o t V e r y N o t I m p o r t a n t I m p o r t a n t I m p o r t a n t I m p o r t a n t I m p o r t a n t V i e u a l P r i v a c y : Qo.cf' 2°'C B o i s e P r i v a c y : 23 A Z-7 O / , b) C e n e r a l I n t e r i o r I m p r e s s i o n  * B o v d o y o u f i n d t h e C e n e r a l L i g h t i n g C o n d i t i o n s ? V e r y Somewhat Q u i t e Too P o o r I n s u f f i c i e n t S u f f i c i e n t B r i g h t B r i g h t O. C-t/ *6-j/- C'Cj/- O • B o v d o y o u f i n d g e n e r a l C o l o u r Scheme ( i n c l u d i n g c a r p e t s , s c r e e n s , f i ' o l t u r e and v a i l ) ? Somewhat A t t r a c t i v e A t t r a c t i v e M e t M o c r e U n a t t r a c t i v e U g l y / / / C ) C e n e r a l E m p l o y e e ' s E x p e c t a t i o n * I f y o u f e e l t h e new o f f i c e l a w o r s e t h s n y o u r p r e v i o u s o n e v l t h r e g a r d t o any o f t h e above a s p e c t s , v h a t do y o u t h i n k s h o u l d be d o n e ? K o r e S c r e e n D i v i d e r s Cc/ R e l o c a t e T o u r Work S t a t l o n _ L a r g e r Work S t a t i o n ;'c-c C o n f i d e n t i a l O f f i c e ACC O t h e r -/f * O v e r a l l , v h a t v o u l d y o u s ay y o u l i k e most abou t t h e open p l a n o f f i c e ? K o r e E f f e c t i v e C o t m u n l c a t l o n /:•••'>'// Improved C e n e r a l C l i m a t e O M o d e r n O f f i c e E q u i p m e n t >'••} O t h e r c> ( c a r p e t s , p l a n t s , e t c ) . - C f c / * r - * / \ 5 A / D ^ ~ > - < / * O v e r a l l , wha t do y o u l i k e l e a s t abou t I t ? T o o P u b l i c & L a c k o f V i s u a l P r i v a c y T e m p e r a t u r e Too Hot u • N o i s e L e v e l T o o H i g h >Y. r' O t h e r U n s a t i s f a c t o r y L i g h t i n g r • T o o Much T r a f f i c 4 L a c k o f Space 0 N o t e : Q u e s t i o n n a i r e s A n s v e r s * The W r i t e r ' s Comment -THE A N A L Y S I S OF DATA O f f i c e & A d d r e s s : F l o o r : T ^ i & w - - i T o t a l Number o f Q u e s t i o n n a i r e s : T o t a l A n s w e r s : THE P H Y S I C A L ENVIRONMENT OF THE OBSERVER » ) T e c h n i c a l I n f o r m a t i o n - S i r e & Shape o f F l o o r P l a n - N e t F l o o r A r e a P e r P e r s o n - C e i l i n g H e i g h t b) L o c a t i o n o f Work S t a t i o n • T a c l n g - ' InJov. • F a c i n g C e n t r a l C o r e e ) The C e n e r : * . N o l a c L e v e l • B o v w o u l d y o u D e s c r i b e N o i s e s O u t s i d e t h a B u i l d i n g V e r y Q u i e t L e s s T h a n N o r m a l A b o u t N o r m a l N o i o y V e r y N o i s y • Hov v o u l d y o u D e s c r i b e t h e C e n e r a l O f f i c e N o i s e V e r y Q u i e t Q u i e t A c c e p t a b l e Somewhat Bad V e r y Bad . _ I K J • I C o - o K er - o 71.-7/ 17*/. o. o S i s / • H o v Do Y o u F i n d C e n e r a l E n v i r o n m e n t C o n d i t i o n s ? P o o r F a i r A c c e p t a b l e C o o d E x c e l l e n t A i r C o n d i t i o n i n g 0 /< 7.6 / 0 ' C ' ' B u i l d i n g H e a t t$.i 57. g e S u n H e a t i n g f r o m Windows O ^70 D . ° / ' I s T h e r e Any W h i t e N o i s e ? Y e s K o * ANNOYANCE L E V E L OF NOISE a ) C h a r a c t e r o f t h e N o i s e t Sound R e f l e c t i o n - C e n t r a l R e f l e c t i o n Ttot< » / V C £ > 5 V J - . T / » C , * - < 3 - L o c a t i o n o f UJ—• ^r*JC-r./HX~fCX<J~p*).CcpJr-- L i g h t i n g Hum, •?>oM<r b ) O f f i c e A c t i v i t i e s t Sound Impac t • N a t u r e o f y o u r w o r k C l e r i c a l - no t y p i n g tS-BjJ C l e r i c a l - v i t h t y p i n g _ ^ ,_.y_ P r o f e s s i o n a l 2C ^>'/ T e c h n i c a l Icf / E x e c u t i v e tc.^"/ O t h e r lO-?/ • W h i c h o f the F o l l o w i n g A c t i v i t i e s do y o u do mos t D u r i n g a Day T y p i n g On T e l e p h o n e . IS-'&j/i F i l i n g c D i c t a t i o n M e e t i n g s C Read O . W r i t e D r a f t i n g 0 0 -J D e s i g n ^tj / e ) I n d i v i d u a l Work A c t i v i t i e s * How M u c h V i s u a l P r i v a c y d o y o u P r e f e r f o r t h e F o l l o w i n g T a s k s ? No P r i v a c y Some P r i v a c y Does N o t M a t t e r A L o t o f P r i v a c y T o t a l P r i v a c y T e l e p h o n e C o n v e r s a t i o n Of. 3 5 . Z zy-s* W o r k i n g b y Y o u r s e l f a t y o u r Work P l a c e 1 O O S m a l l C o n f e r e n c e o f M e e t i n g a t y o u r Work P l a c e 0 •57- « •Z7-0 -2-?/-• How Much P r i v a c y f r o o b e i n g O v e r h e a r d do y o u P r e f e r T a s k s ? f o r t h e F o l l o w i n g Ho P r i v a c y Some P r i v a c y Does No t M a t t e r A L e t o f P r i v a c y T o t a l P r i v a c y T e l e p h o n e C o n v e r s a t i o n •/ It 0 If V ... y W o r k i n g b y Y o u r s e l f a t Y o u r Work P l a c e C / « J . o lei S m a l l C o n f e r e n c e o f M e e t i n g a t Y o u r Work P l a c e 2C.~-> ' Zl.c t*.~?/ * How Much P r i v a c y f r o m N o i s e s O u t s i d e y o u r Work P l a c e do y o u P r e f e r ? No P r i v a c y Some P r i v a c y Does No t M a t t e r A L o t o f P r i v a c y T o t a l P r i v a c y T e l e p h o n e C o n v e r s a t i o n O/ 0 >S -Z S.2. Zi.y W.\ W o r k i n g b y Y o u r s e l f a t Y o u r Work P l a c e to.7 l o - 2 S m a l l C o n f e r e n c e o f M e e t i n g a t Y o u r Work 0 sc.-? fo.sr 42./ P l a c e L O C A T I O N OP SOUND a ) O f f i c e M a c h i n e - T y p e o f a S o u r c e - L o c a t i o n o f a S o u r c e - R e d u c t i o n o f N o i s e b) S p e e c h I n t e r f e r e n c e - The A v e r a g e o f t h e Sound P r e s s u r e L e v e l o f t h e N o i s e e ) W a l l T r e a t m e n t and A b s o r p t i o n . - V a i l M a t e r i a l - C e l l i n g K a t t r l a l - U i n d o v A r e a - F l o o r M a t e r i a l - D e n s i t y o f S c r e e n H a r r i e r s PAivr-T fee-/ THE E X P E R I E N C E OF THE OBSERVERS a ) L e n f i t h o f Er -p loymfn t - B o v many p t o p l o v e r e e m p l o y e d s i n c e t h e d e p a r t m e n t moved i n t o - t h i s b u i l d i n g - ( o r ) b e f o r e t h e move I n t o t h i s b u i l d i n g to/ * W h i c h k i n d o f o f f i c e d i d y o u o c c u p y b e f o r e t h e P r e s e n t One? Open A r e a P r i v a t e O f f i c e * Hov d o e s y o u r p r e s e n t o f f i c e compare v l t h y o u r Fo rmer O f f i c e ? Much B e t t e r Somevhat B e t t e r L i t t l e o r No D i f f e r e n c e Somevhat Worse Much Worse * B o v i m p o r t a n t i s P r i v a c y i n y o u r S p e c i f i c T y p e o f Work? V e r y Somevha t No t V e r y N o t I m p o r t a n t I m p o r t a n t I m p o r t a n t I m p o r t a n t I m p o r t a n t V i s u a l P r i v a c y I 22.4'/' % T'"7 2iS" ^ / N o i s e P r i v a c y : «,l.c' ° °'f ' 2"/ b) C e n e r a l I n t e r i o r I m p r e s s i o n _ . . * Bow d o y o u f i n d t h e C e n e r a l L i g h t i n g C o n d i t i o n s ? V e r y S o m e v h a t Q u i t e T o o P o o r I n s u f f i c i e n t S u f f i c i e n t B r i g h t B r i g h t * B o v d o y o u f i n d g e n e r a l C o l o u r Scheme ( I n c l u d i n g c a r p e t s , s c r e e n s , f u r n i t u r e and v a i l ) ? Somevha t A t t t a c t i v e A t t r a c t i v e M e d i o c r e U n a t t r a c t i v e U g l y C ) G e n e r a l E m p l o y e e ' s E x p e c t a t i o n * I f y o u f e e l t h e n e v o f f i c e I s v o r s e t h a n y o u r p r e v i o u s o n e v l t h r e g a r d t o any o f t h e a b o v e a s p e c t s , v h a t d o y o u t h i n k s h o u l d b a done? K o r e S c r e e n D i v i d e r s 0_ R e l o c a t e T o u r Work S t a t i o n £ £ • V L a r g e r Work S t a t i o n [,. - r / C o n f i d e n t i a l O f f i c e •*>' . , O t h e r lb Ht'.t-tw A?.A /• : * O v e r a l l , v h a t v o u l d y o u s a y y o u l i k e most a b o u t the open p l a n o f f i c e ? K o r e E f f e c t i v e C o m m u n i c a t i o n 17, '/, Improved C e n e r a l C l i m a t e fr..*"* M o d e m O f f i c e E q u i p m e n t O t h e r O ( c a r p e t s , p l a n t s , e t c ) . * O v e r a l l , v h a t do y o u l i k e l e a s t a b o u t i t ? T o o P u b l i c & L a c k o f V i s u a l P r i v a c y T e m p e r a t u r e T o o Hot 7 N o i s e L e v e l T o o H l g'i \ ? i O t h e r n . 7 U n s a t i s f a c t o r y L i g h t i n g ; 7 _ J T o o Much T r a f f i c 4 L a c k o f S p a c e N o t e : Q u e s t i o n n a i r e s A n s w e r s * The W r i t e r ' s Comment -THE A N A L Y S I S OF DATA O f f i c e 4 A d d r e s s : 5"f-7 C i o E E - A f t D F l o o r : Tkir-rrr-/ " P o u r X T o t a l Number o f Q u e s t i o n n a i r e s : 2o T o t a l A n s w e r s : 2>0 — - T- »<-o THE P H Y S I C A L ENVIRONMENT OF THE OBSERVER a ) T e c h n i c a l I n f o r m a t i o n - S i r e & Shape o f F l o o r P l a n - N e t F l o o r A r e a P e r P e r s o n - C e l l i n g H e i g h t b) L o c a t i o n o f Work S t a t i o n * Facing V.'ir.csv * F a c i n g C e n t r a l C o r e c ) The C e n e r a l N o i s e L e v e l * Hov w o u l d y o u D e s c r i b e N o i s e s O u t s i d e t h e B u i l d i n g V a r y Q u i e t L e s s T h a n N o r m a l A b o u t N o r m a l N o i s y V e r y N o i s y * Hov v o u l d y o u D e s c r i b e t h e C e n e r a l O f f i c e N o i s e V e r y Q u i e t Q u i e t A c c e p t a b l e Somewhat Bad V e r y Bad 11? - 0 >cMC-o f2oSo.F-C j ' - o " a s / . o is* o . O o Co/, * H o v Do T o u F i n d C e n e r a l E n v i r o n m e n t C o n d i t i o n s ? P o o r F a i r A c c e p t a b l e C o o d E x c e l l e n t A i r C o n d i t i o n i n g '/. "Zo *0 Zo "? B u i l d i n g H e a t ( 0 K l O ' 3 sT ^ S u n H e a t i n g f r o m W i n d o v s - v ^ " \Q | J ' le/-- I s T h e r e A n y W h i t e N o i s e ? N o ANNOTANCE L E V E L OF N O I S E a ) C h a r a c t e r o f t h e N o l s e & *~ound Re f l e e • '.on - C e n e r a l R e f l e c t i o n T £ O M WBP'pWAaS - L o c a t i o n o i rt/'.'-" C*arJ*rAj>-V^j A**-**: u i u O c - J - L i g h t i n g Hum U J T M o T l O ' C . C O -. *>) O f f i c e A c t i v i t i e s 4 Sound I m p a c t • N a t u r e o f y o u r v o r k C l e t l c a l - n o t y p i n g © C l e r i c a l - v l t h t y p i n g * ° ' / ' P r o f e s s i o n a l '/' T e c h n i c a l « ; E x e c u t i v e £ / • • O t h e r • W h i c h o f t h e F o l l o w i n g A c t i v i t i e s do y o u d o m o s t D u r i n g a Day T y p i n g 0 On T e l e p h o n e ^ , / F i H n f f %/• Read c? cn o " l i n g D i c t a t i o n -M e e t i n g s W r i t e a D r a f t i n g — — - . . ^ D e s i g n C e ) I n d i v i d u a l Work A c t i v i t i e s * How Much V i s u a l P r i v a c y do y o u P r e f e r f o r t h e F o l l o w i n g T a s k s ? No P r i v a c y Some P r i v a c y Does No t M a t t e r A L o t o f P r i v a c y T o t a l P r i v a c y T e l e p h o n e C o n v e r s a t i o n *P • J O 20 W o r k i n g b y Y o u r s e l f a t y o u r Work P l a c e rro S m a l l C o n f e r e n c e o f M e e t i n g a t y o u r Work P l a c e O 2o / • How Much P r i v a c y f r o m b e i n g O v e r h e a r d do y o u P r e f e r T a s k s ? f o r t h e F o l l o w i n g No P r i v a c y Some P r i v a c y Does Not M a t t e r A L o t o f P r i v a c y T o t a l P r i v a c y T e l e p h o n e C o n v e r s a t i o n 10'/. >£> iv v <Z W o r k i n g b y Y o u r s e l f a t Y o u r Work P l a c e 10 T / r S a a i l C o n f e r e n c e o f M a e t l n g a t Y o u r Work P l a c e 0 to/. • How Much P r i v a c y f r o o N o i s e s O u t s i d e y o u r Work P l a c e do y o u P r e f e r ? No P r i v a c y Some P r i v a c y Does Not M a t t e r A L o t o f P r i v a c y T o t a l P r i v a c y T e l e p h o n e C o n v e r s a t i o n £->~ W o r k i n g b y Y o u r s e l f a t Y o u r Work P l a c e to S m a l l C o n f e r e n c e o f M e e t i n g a t Y o u r Work ST 4o 0 zer '7. P l a c e LOCATION OF SOUND a) O f f i c e M a c h i n e - T y p e o f a S o u r c e - L o c a t i o n o f a S o u r e e - R e d u c t i o n o f N o i s e b ) S p e e c h I n t e r f e r e n c e - The A v e r a g e o f t h e Sound P r e s s u r e L e v e l o f t h e N o i s e e ) W a l l T r e a t c e n t and A b s o r p t i o n - W a l l M a t e r i a l - C e i l i n g M a t e r i a l - Window Area - F l o o r M a t e r i a l - Density ot St i c c i ) S i l l i e r J vinyl U/M.^ r-p/.f"e^ THE E X P E R I E N C E OF THE OBSERVERS a ) L e n g t h o f E n p l o y m e n t - How many p e o p l e w e r e e m p l o y e d s i n c e t h o d e p a r t m e n t moved i n t o t h i s b u i l d i n g & ' / - ( o r ) b e f o r e t h e move I n t o t h i s b u i l d i n g ^ * * / * W h i c h k i n d o f o f f i c e d i d y o u o c c u p y b e f o r e t h e P r e s e n t One? Open A r e a * How d o e s y o u r p r e s e n t o f f i c e compare w i t h y o u r F o r m e r O f f i c e ? P r i v a t e O f f i c e Much Somewhat L i t t l e o r Somewhat Much B e t t e r B e t t e r No D i f f e r e n c e Worse Worse e*>/. 1?/. 10/ Hov I m p o r t a n t i s P r i v a c y I n y o u r S p e c i f i c Type o f W o r k ? V e r y Somewhat N o t V e r y H o t I m p o r t a n t I m p o r t a n t I m p o r t a n t I m p o r t a n t I m p o r t a n t V i s u a l P r i v a c y : / o / . ?0 5 0 J S " ^ N o i s e P r i v a c y : Z ^ * ° b ) C e n e r a l I n t e r i o r I m p r e s s i o n * Hov d o y o u f i n d t h e C e n e r a l L i g h t i n g C o n d i t i o n s ? V e r y Somewhat Q u i t e T o o P o o r I n s u f f i c i e n t S u f f i c i e n t B r i g h t B r i g h t D O *)o'/ IP'/- O * How d o y o u f i n d g e n e r a l C o l o u r Schema ( I n c l u d i n g c a r p e t s , s c r e e n s , f u ' j l t u r e and v a i l ) ? Somewhat A t t r a c t i v e A t t r a c t i v e M e d i o c r e . U n a t t r a c t i v e U g l y C ) C e n e r a l E m p l o y e e ' s E x p e c t a t i o n * I f y o u f e e l t h e n e v o f f i c e I s w o r s e t h a n y o u r p r e v i o u s one w i t h r e g a r d t o any o f t h e above a s p e c t s , v h s t do y o u t h i n k s h o u l d b e done? M o r e S c r e e n D i v i d e r s ^ / R e l o c a t e T o u r Work S t a t i o n % / ' L a r g e r Work S t a t i o n p C o n f i d e n t i a l O f f i c e ./ O t h e r >~" * O v e r a l l , w h a t w o u l d y o u s a y y o u l i k e mos t abou t t h e o p e n p l a n o f f i c e ? M o r e E f f e c t i v e C o m m u n i c a t i o n &e- '/• I m p r o v e d C e n e r a l C l i m a t e d/ ' M o d e m O f f i c e E q u i p m e n t O t h e r _ ( c a r p e t s , p l a n t s , e t c ) . * O v e r a l l , wha t d o y o u l i k e l e a s t a b o u t i t ? T o o P u b l i c & L a c k o f V i s u a l P r i v a c y 7r T e m p e r a t u r e T o o H o t ? N o i s e L e v e l T o o H i g h O t h e r U n s a t i s f a c t o r y L i g h t i n g c_ Too Much T r a f f i c & L a c k o f S p a c e Q_ N o t e : Q u e s t i o n n a i r e s A n s w e r s * The W r i t e r ' s Comment -THE A N A L Y S I S OF DATA O f f i c e & A d d r e s s : i.'&e> &e.4-HVl(CC-F l o o r : T^e^Ty 7WQ „ i~ y, T o t a l Number o f Q u e s t l o n n s l r e s t * " ' 1 0 0 / ' T o t a l A n s w e r s : BS.CZ.'/. THE P H Y S I C A L ENVIRONMENT OF THE OBSERVER a ) T e c h n i c a l I n f o r m a t i o n ^ I - S i r e & Shape o f F l o o r P l a n I1&-C. X ?2-G - N e t F l o o r A r e a P e r P e r s o n - C e l l i n g H e i g h t • <d~o'f b) L o c a t i o n o f Work S t a t i o n * F a c i n g Window * F a c i n g C e n t r a l C o r e c ) The C e n e r a l N o l » e L e v e l * How w o u l d y o u D e s c r i b e N o i s e s O u t s i d e t h e B u i l d i n g V e r y Q u i e t , L e s s T h a n N o r m a l A b o u t N o r m a l N o i s y V e r y N o i s y * How w o u l d y o u D e s c r i b e t h e C e n e r a l O f f i c e N o i s e V e r y Q u i e t Q u i e t C. A c c e p t a b l e ^ 2 - 2 / ^ 17-i/' o. o. Somewhat Bad V e r y Bad *How Do T o u F i n d C e n e r a l E n v i r o n m e n t C o n d i t i o n s ? P o o r F a i r A c c e p t a b l e C o o d E x c e l l e n t A i r C o n d i t i o n i n g 5". S,J . ? y f d l s-B u i l d i n g H e a t 0 , ? ? ^ | " / f i _ S u n H e a t i n g f r o o Windowa 1-^> tO.V • f o ' 2 ^ C o . t - I s T h e r e A n y W h i t e N o i s e ? T e a . No X  ANNOYANCE L E V E L OF NOISE a) C h a r a c t e r o f t h e N o i s e t S e u n d R e f l e c t i o n - C e n e r s l R e f l e c t i o n T<~C*J **-Art.£> r^yejtUZcy - L o c a t i o n o t '\J-r>- o.'eyvot?^>t(^ 4<r*c triuuc^j> - L i g h t i n g Hum i<IOH-7ty f+oTi Cr / I ^ T b) O f f i c e A c t i v i t i e s * Sound I m p a c t • N a t u r e o f y o u r w o r k C l e r i c a l - n o t y p i n g C l e r i c a l - - w i t h t y p i n g P r o f e s s i o n a l T e c h n i c a l E x e c u t i v e O t h e r • W h i c h o f t h e F o l l o w i n g A c t i v i t i e s d o y o u d o mos t D u r i n g a Day T y p i n g On T e l e p h o n e F i l i n g D i c t a t i o n M e e t i n g s Read W r i t e D r a f t i n g D e s i g n C-tC-6/. o o o o (6-6 / >-=> to e ) I n d i v i d u a l Work A c t i v i t i e s * Hov Much V i s u a l P r i v a c y do y o u P r e f e r f o r t h e F o l l o w i n g T a s k s ? Ho P r i v a c y Some P r i v a c y Does No t M a t t e r A L o t o f P r i v a c y T o t a l P r i v a c y T e l e p h o n e C o n v e r s a t i o n /St5 fa- f r W o r k i n g b y Y o u r s e l f a t y o u r Work P l a c e "I Sb.o ll/ II-f S m a l l C o n f e r e n c e o f M e e t i n g a t y o u r Work P l a c e 10,1 If. 7, » Hov Much P r i v a c y f rom T a s k s ? b e i n g O v e r h e a r d do y o u P r e f e r f o r t h e F o l l o v i n g K o P r i v a c y Some P r i v a c y Does Not M a t t e r A L o t o f P r i v a c y T o t a l P r i v a c y T e l e p h o n e C o n v e r s a t i o n 12-7 • • W o r k i n g b y T o u r s e l f a t T o u r Work P l a c e 10.7 io.Z- Z.S4 S m a l l C o n f e r e n c e o f M e e t i n g a t Y o u r Work 0 III 11? P l a c e * B o v Much P r i v a c y f r o m N o i s e s O u t s i d e y o u r Work P l a c e do y o u P r e f e r ? No Some Does No t A L o t o f T o t a l P r i v a c y P r i v a c y M a t t e r P r i v a c y P r i v a c y T e l e p h o n e C o n v e r s a t i o n $~)/' ' f r Z» «2?-7 S'?. W o r k i n g b y Y o u r s e l f „ . St Y o u r Work P l a c e f ^ J ?4Jf lt>-f ^ S • ^ S m a l l C o n f e r e n c e o f \ > r J / M e e t i n g a t Y o u r Work 0 • 2 - H-l 17i' -»'•// P l a c e LOCATION OF SOUND a ) O f f i c e M a c h i n e - T y p e o f a S o u r c e - L o c a t i o n o f a S o u r c e - R e d u c t i o n o f N o i s e b) S p e e c h I n t e r f e r e n c e The A v e r 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 o f t h e N o i s e e ) W a l l T r e a t m e n t and A b s o r p t i o n - W a l l M a t e r i a l - C e l l i n g M a t e r i a l - Window A r e a - F l o o r M a t e r i a l - D e n s i t y o f S c r e e n B a r r i e r s •75/ THE E X P E R I E N C E OF THE OBSERVERS a ) L e n g t h o f E r . p l o y m e n t - Bow many p e o p l e v e r a e m p l o y e d s i n c e t h e d e p a r t m e n t moved i n t o t M s b u i l d i n g - ( o r ) b e f o r e t h e move i n t o t h i s b u i l d i n g * W h i c h k i n d o f o f f i c e d i d y o u o c c u p y b e f o r e t h e P r e s e n t One? Open A r e a P r i v a t e O f f i c e * Hov d o c s y o u r p r e s e n t o f f i c e c o m p a r t v l t h y o u r F o r m e r O f f i c e ? Much B e t t e r Somevha t B e t t e r L i t t l e o r No D i f f e r e n c e S c i e v h a t Worse Much W o r s e * B o v I m p o r t a n t i s P r i v a c y i n y o u r S p e c i f i c Type o f Work? V e r y Somevhat N o t V e r y N o t I m p o r t a n t I m p o r t a n t I m p o r t a n t I m p o r t a n t I m p o r t a n t V i s u a l P r i v a c y : I4.& '/, ZC-t, -Zo.^ 2>o.«S <• Z N o i s e P r i v a c y : C+. C ^ '/. b) C e n e r a l I n t e r i o r I m p r e s s i o n - . * B o v do y o u f i n d t h e C e n e r a l L i g h t i n g C o n d i t i o n s ? V e r y Somevha t Q u i t e T o o P o o r I n s u f f i c i e n t S u f f i c i e n t B r i g h t B r i g h t O S . C ' / . T i t / . I C & f X * H o v d o y o u f i n d g e n e r a l C o l o u r Scheme ( i n c l u d i n g c a r p e t s , s c r e e n s , f u r n i t u r e and v a i l ) ? Somevhat A t t r a c t i v e A r - r « r t i v « M e d i o c r e U n a t t r a e t l v a U g l y C) C e n e r a l E m p l o y e e ' s E x p e c t a t i o n * I f y o u f e e l t h e n e v o f f i c e I s v o r s e t h a n y o u r p r e v i o u s one v i t h r e g a r d t o any o f t h e above a s p e c t s , v h a t do y o u t h i n k s h o u l d be done? More S c r e e n D i v i d e r s U C R e l o c a t e T o u r Work S t a t l o n _ L a r g e r Work S t a t i o n / / • / C o n f i d e n t i a l O f f i c e , y . y> O t h e r r-1'- • 1> * O v e r a l l , v h a t v o u l d y o u s a y y o u l i k e most abou t the open f an o f f i c e ? More E f f e c t i v e C o m j u n l c a t l o n - 7 Improved C e n e r a l C l i m a t e '~<T M o d e r n O f f i c e E q u i p m e n t .".'-'L. O t h e r f~7 S ( c a r p e t s , p l a n t s , e t c ) . ' * O v e r a l l , v h a t do y o u l i k e l e a s t a b o u t I t ? T o o P u b l i c 4 L a c k o f V i s u a l P r i v a c y T e m p e r a t u r e T o o Hot N o i s e L e v e l T o o H i g h O t h e r c< U n s a t i s f a c t o r y L i g h t i n g r,y T o o Much T r a f f i c 4 L a c k o f Space /•> N o t e : Q u e s t i o n n a i r e s A n s w e r s • The W r i t e r ' s Comment -THE A N A L Y S I S OF DATA O f f i c e & A d d r e s s : 2<^<j C(^U\J{ LUz F l o o r : TIAJ rr-ATTV TUll?-T-> T o t a l Number o f Q u e s t i o n n a i r e s : *"?o - J V \r~«,'/. T o t a l A n s w e r s : fZO ' ' '. loc/. THE P H Y S I C A L ENVIRONMENT OF THE OBSERVER • ) T e c h n i c a l I n f o r t \ a t l o n - S i r e 4 Shape o f F l o o r P l a n - N e t F l o o r A r e a P e r P e r s o n - C e l l i n g H e i g h t 9-° b) L o c a t i o n o f Work S t a t i o n * F a c i r - c V l r . d c v * F a c i n g C e n t r a l C o r e e ) The C e n e r a l N o i s e L e v e l * Hov v o u l d y o u D e s c r i b e N o i s e s O u t s i d e t h e B u i l d i n g V e r y Q u i e t L e s s T h a n N o r r a l A b o u t N o r m a l N o i s y V e r y N o i s y * Hov v o u l d y o u D e s c r i b e t h e C e n e r a l O f f l e e N o i s e V e r y Q u i e t Q u i e t A c c e p t a b l e Somevha t Bad V e r y Bad Zo/. 2 - / iu y. o so? to'/ • H o v Do Tern F i n d C e n e r a l E n v i r o n m e n t C o n d i t i o n s ? P o o r A i r C o n d i t i o n i n g > o / ' B u i l d i n g H e a t C S u n H e a t i n g f r o o Windows A-0 I s T h e r e A n y W h i t e H o l s e ? T e s F s l r A c c e p t a b l e C o o d E x c e l l e n t 2 o ro 45" O 4 0 S O • O / ANNOYANCE L E V E L OP NOISE a ) C h a r a c t e r o f the N o i s e t *ound R e f l e t ' i o n - C e n e r a l R e f l e c t i o n T f i o w M^fTJ^rvRTV.^---^ - L o c a t i o n o f <f>rr**r<vsU._/ /y .wc - L i g h t i n g Hua ^UG*--rt>7 /AnCTTAetC-b) O f f i c e A c t i v i t i e s & Sound I m p a c t • N a t u r e o f y o u r w o r k C l e r i c a l - no t y p i n g ey. C l e r i c a l - v l t h t y p i n g t S ' / P r o f e s s i o n a l T e c h n i c a l E x e c u t l v o is'y, O t h e r tO'/ • W h i c h o f the F o l l o w i n g A c t i v i t i e s do y o u do most i°y, D u r i n g a Day T y p i n g 2o /• On T e l e p h o n e <2o/, 0 F i l i n g D i c t a t i o n • — O M e e t i n g s (0 /, Read W r i t e D r a f t i n g D e s i g n 0 0 c) I n d i v i d u a l Work A c t i v i t i e s • Hov Much V l s u s l P r i v a c y d o y o u P r e f e r f o r t h e F o l l o w i n g T a s k a ? No P r i v a c y Some P r i v a c y Does N o t M a t t e r A L o t of P r i v a c y T o t a l P r i v a c y T e l e p h o n e C o n v e r s a t i o n W o r k i n g by Y o u r s e l f a t y o u r Work P l a c e O 2o zo S m a l l C o n f e r e n c e o f M e e t i n g a t y o u r Work P l a c e IO ta 2 C * How Much P r i v a c y f r o m T a s k s ? b e i n g O v e r h e a r d do y o u P r e f e r for t h e F o l l o w i n g No P r i v a c y Some P r i v a c y Does No t H a t t e r A L o t of P r i v a c y T o t a l P r i v a c y T e l e p h o n e C o n v e r s s t l o n W o r k i n g by Y o u r s e l ' a t Y o u r Work P l a c e U SB 4c 4T 5" 2o S m a l l C o n f e r e n c e o f K e a t i n g a t Y o u r Work P l a c e 0 4s~ 10 • Hov Much P r i v a c y f r o m N o i s e s O u t s i d e y o u r Work P l a c e do y o u P r e f e r ? No P r i v a c y Some P r i v a c y Does No t M a t t e r A L o t of P r i v a c y T o t a l P r i v a c y T e l e p h o n e C o n v e r s s t l o n W o r k i n g b y Y o u r s e l f a t Y o u r Work P l a c e /o> 5" 40 4V ?o (0 S o S" IO M e e t i n g a t Y o u r Work O £ r > . ^ " ^ " a * Jo P l a c e ^ ° ^ LOCATION OF SOUND a ) O f f i c e M a c h i n e - T y p e o f a S o u r c e 1 / ' ^ - L o c a t i o n o f a S o u r c e t A C T l M v y <5*CUf?rO - R e d u c t i o n o f N o i s e TbS->iij.6c-b) S p e e c h I n t e r f e r e n c e " ' The A v e r a g e o f t h e Sound P r e s s u r e L e v e l . of t h e Kola. ic*-5-TV-AW o f t e N o i s e c ) W a l l T r e a t m e n t and A b s o r p t i o n - W a l l M a t e r i a l TJft IAjT/\J\ir-/(_ "T7 LC - C e l l i n g M a t o r l a l r * ^ r * r O . £,LArr? - Window A r e a ~~75'/' - F l o o r M a t e r i a l C-AP-f-Tr~J - t c n a l l y u i Siiitta B a r r i e r s ^iV PHJ,\-I THE E X P E R I E N C E OF THE OBSERVERS a ) L e n g t h o f Employment - How many p e o p l e were e m p l o y e d s i n c e t h e d e p a r t m e n t "7o'/. moved l n t o - t h l s b u i l d i n g - ( o r ) b e f o r e the move I n t o t h i s b u i l d i n g * W h i c h k i n d o f o f f i c e d i d y o u o c c u p y b e f o r e t h e P r e s e n t One? Open A r e a P r i v a t e O f f i c e • Row d o e a y o u r p r e s e n t o f f i c e compare w i t h y o u r F o r m e r O f f i c e ? Much Soaewhs t L i t t l e o r Somewhat Much B e t t e r B e t t e r No D i f f e r e n c e Worse Worse IT/' 2 0 / try *y • How i m p o r t a n t i s P r i v a c y i n y o u r S p e c i f i c T y p e o f W o r k ? V e r y Somewhat N o t V e r y N o t I m p o r t a n t I m p o r t a n t I m p o r t a n t I m p o r t a n t I m p o r t a n t V i s u a l P r i v a c y : I?. 4 /• * 2 z 4 Zi.P <> H o l s e P r i v a c y : Z1. S ~ 2 * * ° / ' b ) C e n e r a l I n t e r i o r I m p r e s s i o n  * How d o y o u f i n d t h e C e n e r a l L i g h t i n g C o n d i t i o n s ? V e r y Somewhat Q u i t e Too P o o r I n s u f f i c i e n t S u f f i c i e n t B r i g h t . B r i g h t o o 7s~y vf/' ~° * Row d o y o u f i n d g e n e r a l C o l o u r Schema ( i n c l u d i n g c a r p e t * , s c r e e n s , f u r n i t u r e and w a l l ) ? Somewhat A t t r a c t i v e A t t r a c t i v e M e d i o c r e U n a t t r a c t i v e U g l y - Z r - r / 4 o / o C) C e n e r a l E m p l o y e e ' s E x p e c t a t i o n » I f y o u f e e l t h e new o f f i c e I s w o r s e t h a n y o u r p r e v i o u s one w i t h r e g a r d t o any o f t h e s b o v e a s p e c t s , what d o y o u t h i n k s h o u l d b a d o n e ? M o r e S c r e e n D i v i d e r s '*> R e l o c a t e T o u r Work S t a t i o n _ L a r g e r Work S t a t i o n _ " " C o n f i d e n t i a l O f f i c e , , „ • , / O t h e r * O v e r a l l , w h a t w o u l d y o u s a y y o u I l k a most a b o u t t h e o p e n p l a n o f f i c e ? More E f f e c t i v e C o m m u n i c a t i o n I m p r o v e d C e n e r a l C l i m a t e 7T~ M o d e r n O f f i c e E q u i p m e n t ••' >" O t h e r />.' ( c a r p e t s , p l a n t s , e t c ) . * O v e r a l l , wha t do y o u l i k e l e a s t a b o u t i t ? T o o P u b l i c S L a c k o f V i s u a l P r i v a c y , t T e m p e r a t u r e T o o H o t (T N o i s e L e v e l Too H i g h : O t h e r _) U n s a t i s f a c t o r y L i g h t i n g T o o Much T r a f f i c & L a c k o f S p a c e Zo N o t e : Q u e s t i o n n a i r e s A n s v e r e * The W r i t e r ' s Comment -THE A N A L Y S I S OF DATA O f f i c e & A d d r e s a : Zoo <• e^U \ji C l C F l o o r : ' T u j c i _ n - y ~F*Wrz T o t a l Number o f Q u e s t i o n n a i r e s : £ o •""""» \ot>y. T o t a l A n s w e r s : Z.O l o o / ' -THE P H Y S I C A L ENVIRONMENT OF THE OBSERVER a ) T e c h n i c a l I n f o r m a t i o n - S i t e & Shape o f F l o o r P l a n IJ&'-oV Y-i'-o" - N e t F l o o r A r e a P e r P e r s o n I2ci--c».r* - C e l l i n g H e i g h t 9 - o " b) L o c a t i o n o f Work S t a t i o n * F a c i n g Window * F a c i n g C e n t r a l C o r e t V / ' ' e ) The C e n e r a l N o i s e L e v e l * How w o u l d y o u D e s c r i b e N o i s e s O u t s i d e t h e B u i l d i n g V a r y Q u i e t L e s s Than N o r m a l A b o u t N o r e a l N o i s y V e r y N o i s y la/ ^ / o * How v o u l d y o u D e s c r i b e t h e C e n e r a l O f f i c e N o i s e V e r y Q u i e t O Q u i e t cV A c c e p t a b l e / ' Somevhat Bad * ? V / ^ V e r y Bad | U / . •How Do Y o u F i n d C e n e r a l E n v i r o n m e n t C o n d i t i o n s ? P o o r A i r C o n d i t i o n i n g g </, B u i l d i n g Hea t i0' Sun H e a t i n g f r o m Windows cJ - l a T h e r e A n y W h i t e N o i s e ? Y e s No _ X F a i r A c c e p t a b l e C o o d E x c e l l e n t S o 4o 4o ' / «?" Zo 5>0 10 -A ANNOYANCE L E V E L OF NOISE a ) C h a r a c t e r o f t h e N o i s e * . 'ound R e f l e e - -on - C e n e r a l R e f l e c t i o n T r t o u K - A ^ o • R * ? r . a c * r * * > - L o c a t l u n o f '\u.^> li^eur^Ml^ MJJJC UiXMt^l - L i g h t i n g Hum ^UCitTl^ j/---w>.C.&> b) O f f i c e A c t i v i t i e s t Sound I r . p a c t • N a t u r e o f y o u r v o r k C l e r i c a l - no t y p i n g '/• C l e r i c a l - w i t h t y p i n g P r o f e s s i o n a l h£/ T e c h n i c a l 1^/' E x e c u t i v e ^ ~ / ' O t h e r / • • W h i c h o f t h e F o l l o w i n g A c t i v i t i e s d o y o u do o o s t D u r i n g a Day T y p i n g On T e l e p h o n e F i l i n g O D i c t a t i o n • O M e e t i n g s O R e a d O ^ W r i t e CO D r a f t i n g D e s i g n O I n d i v i d u a l Work A c t i v i t i e s * How Much V i s u a l P r i v a c y do y o u P r e f e r f o r t h e F o l l o w i n g T a a k a T T e l e p h o n e C o n v e r s a t i o n W o r k i n g b y Y o u r s e l f a t y o u r Work P l a c e S m a l l C o n f e r e n c e o f M e e t i n g a t y o u r Work P l a c e Ho Soae Does N o t A L o t o f T o t a l P r i v a c y P r i v a c y M a t t e r P r i v a c y P r i v a c y to o AO to X) to 4-<r *T * Row Much P r i v a c y f rom b e i n g O v e r h e a r d do y o u P r e f e r f o r t h e F o l l o w i n g T a s k s 7 No Soae Does Not A L o t o f T o t a l P r i v a c y P r i v a c y M a t t e r P r i v a c y P r l v a c y T e l e p h o n e C o n v e r s a t i o n V f to IT W o r k i n g by Y o u r s e l f a t Y o u r Work P l a c e IO S m a l l C o n f e r e n c e o f M e e t i n g a t Y o u r Work P l a c e o ss-* How Much P r i v a c y f rom N o i s e s O u t s i d e y o u r Work P l a c e do y o u P r e f e r ? No P r i v a c y S0t&6 P r i v a c y Does No t H a t t e r A L o t o f P r i v a c y T o t a l P r i v a c y T e l e p h o n e C o n v e r s a t i o n f t AO 1C •So <?T W o r k i n g by Y o u r s e l f i t T o u r Work P l a c e 0 10 S m a l l C o n f e r e n c e o f M e e t i n g a t Y o u r Work P l a c e 0 io ?r-LOCATION OF SOUND a ) O f f i c e M a c h i n e - Type o f a S o u r c e - L o c a t i o n o f a S o u r c e - R e d u c t i o n o f N o i s e b) S p e e c h I n t e r f e r e n c e - The A v e r a g e o f t h e Sound P r e s s u r e L e v e l o f t h e N o i s e c) W a l l T r e a t m e n t and A b s o r p t i o n - W a l l M a t e r i a l - C e l l i n g M a t e r i a l - Window A r e a - F l o o r M a t e r i a l - D e n s i t y o f S c r - e n * . « r r 1 * T « TRE E X P E R I E N C E OF THE OBSERVERS a ) L e n g t h o f Employment - How many p e o p l e we re e m p l o y e d t i n e a t h a d e p a r t m e n t moved l n t c t h i s b u i l d i n g - ( o r ) b e f o r e t h e move I n t o t h i s b u i l d i n g * W h i c h k i n d o f o f f i c e d i d y o u o c c u p y b e f o r e t h e P r e s e n t One? Open A r e a P r i v a t e O f f i c e •S.CT/ £*y * How d o e s y o u r p r e s e n t o f f i c e c o m p a r e w i t h y o u r F o n s e r O f f i c e ? 7 o / Much B e t t e r Somewhat B e t t e r L i t t l e o r No D i f f e r e n c e Somewhat Much Worse Worse i>rf io/,- zc / wy, * How i m p o r t a n t i s P r i v a c y i n y o u r S p e c i f i c T y p e o f W o r k ? V e r y Somewhat H o t V e r y H o t I m p o r t a n t I m p o r t a n t I m p o r t a n t I m p o r t a n t I m p o r t a n t V i s u a l P r i v a c y I / S . < ? / 2?-6 °' N o i s e P r i v a c y : ?2.7. <? iC* 3 - ^ ' O'/• b) C e n e r a l I n t e r i o r I m p r e s s i o n * How d o y o u f i n d t h e C e n e r a l L i g h t i n g C o n d i t i o n s ? V e r y Somewhat Q u i t e T o o P o o r I n s u f f i c i e n t S u f f i c i e n t B r i g h t B r i g h t $'/. 10/. W/, * How do y o u f i n d g e n e r a l C o l o u r Scheme ( I n c l u d i n g c a r p e t s , s c r e e n s , f u r n i t u r e and w a l l ) ? Somewhat A t t r a c t i v e A t t r a c t i v e M e d i o c r e U n a t t r a c t i v e U g l y £>'// «->/'/ , 0 / '•'/' C) C e n e r a l E m p l o y e e ' s E x p e c t a t i o n * I f y o u f e e l the new o f f i c e I s w o r s e t h a n y o u r p r e v i o u s one w i t h r e g a r d t o any o f the above a s p e c t s , v h a t d o y o u t h i n k s h o u l d be done? M o r e S c r e e n D i v i d e r s R e l o c a t e T o u r V o r k S t a t i o n lo_ L a r g e r Work S t a t i o n • • / , C o n f i d e n t i a l O f f i c e . / O t h e r ^ / * O v e r a l l , wha t w o u l d y o u s ay y o u I l k a most abou t the o p e n p l a n o f f i c e ? More E f f e c t i v e C o m m u n i c a t i o n If,* I m p r o v e d C e n e r a l C l i m a t e 'V* M o d e r n O f f i c e E q u i p m e n t O t h e r ( j j ( c a r p e t s , p l a n t s , e t c ) . * O v e r a l l , w h a t do y o u l i k e l e a s t a b o u t I t ? Too P u b l i c h, L a c k o f V i s u a l P r i v a c y T e m p e r a t u r e T o o H o t h N o i s e L e v e l Too H i g h <±^_~ O t h e r ; Q U n s a t i s f a c t o r y L i g h t i n g ^7 T o o Much T r a f f i c & L a c k o f Space [j£ 

Cite

Citation Scheme:

        

Citations by CSL (citeproc-js)

Usage Statistics

Share

Embed

Customize your widget with the following options, then copy and paste the code below into the HTML of your page to embed this item in your website.
                        
                            <div id="ubcOpenCollectionsWidgetDisplay">
                            <script id="ubcOpenCollectionsWidget"
                            src="{[{embed.src}]}"
                            data-item="{[{embed.item}]}"
                            data-collection="{[{embed.collection}]}"
                            data-metadata="{[{embed.showMetadata}]}"
                            data-width="{[{embed.width}]}"
                            async >
                            </script>
                            </div>
                        
                    
IIIF logo Our image viewer uses the IIIF 2.0 standard. To load this item in other compatible viewers, use this url:
http://iiif.library.ubc.ca/presentation/dsp.831.1-0093722/manifest

Comment

Related Items