Message and talker identification in older adults: effects of task, distinctiveness of the talkers' voices, and meaningfulness of the competing message.

PURPOSE: In this study, the authors investigated (a) the effects of task, vocal distinctiveness of the competing talkers, and meaningfulness of the competitor on older listeners' identification of a target in the presence of competition and (b) the factors that are most predictive of the variability in target identification observed among older listeners.
METHOD: Seventeen older and 5 younger adults identified a target in the presence of a competing message. Identification was measured for 2 target types (message; talker), 3 vocal-distinctiveness levels (same talker; different talkers-same sex; different talkers-different sex), and 2 competitors (meaningful speech; nonmeaningful time-reversed speech). Multiple regression analyses were used to identify variables that were predictive of intersubject variability.
RESULTS: Significant age-related differences were found in the benefit obtained from increasing vocal distinctiveness. Older listeners showed reduced target identification when (a) the competitor was normal speech compared with time-reversed speech and (b) the target was message identification compared with talker identification. Variability among listeners in the older group was partially explained by auditory and cognitive factors.
CONCLUSION: Age-related declines in multitalker environments are not solely due to lower-level deficits in perceptual organization but are also a consequence of an interaction between lower-level and higher-level processes.