UBC Theses and Dissertations
Adaptation to compressed speech in younger and older listeners Lam, Wendy
The present study investigated age differences in adaptation to compressed speech using a sentence recall task. Ten younger adults (aged 20-30 years) and 10 older adults (aged 62-78 years) were presented with 15 sentences at a naturally accelerated rate of 265 wpm (68% time compression), 15 sentences at a normal rate of 180 wpm, and then another 15 sentences at 265 wpm. Participants were instructed to listen to each sentence and recall it out loud as accurately as possible. Performance was evaluated in terms of the proportion of words correctly recalled. In view of known decrements in temporal processing, working memory capacity, and processing speed with age, older adults were expected to perform more poorly than younger adults at the accelerated speech rate. However, the results revealed no age differences in performance. Rather than impairing recall as predicted, moderate acceleration of speech rate had no effect on the performance of older participants and slightly enhanced that of younger participants. The results also offered preliminary evidence of adaptation to accelerated speech by a subgroup of younger and older participants who exhibited an improvement in recall performance over the course of 15-20 sentences. Furthermore, participants who demonstrated adaptation did not return to their original unadapted performance level after they were presented with uncompressed speech. This indicates that improvement in performance over the course of exposure to rapid input may reflect a learning process. Finally, it was hypothesized that the older group would adapt at a slower rate and to a lesser extent than the younger group due to age-related deficits in temporal/perceptual and cognitive processing. Although there were such age differences in the rate and degree of adjustment among participants who demonstrated adaptation, the effects were not statistically significant.
Item Citations and Data