Cognitive resources related to speech recognition with a competing talker in young and older listeners

Speech recognition in a multi-talker situation poses high demands on attentional and other central resources. This study examines the relationship between age, cognition and speech recognition in tasks that require selective or divided attention in a multi-talker setting. Two groups of normal-hearing adults (one younger and one older group) were asked to repeat utterances from either one or two concurrent speakers. Cognitive abilities were then inspected by neuropsychological tests. Speech recognition scores approached its ceiling and did not significantly differ between age groups for tasks that demanded selective attention. However, when divided attention was required, performance in older listeners was reduced as compared to the younger group. When selective attention was required, speech recognition was strongly related to working memory skills, as determined by a regression model. In comparison, speech recognition for tests requiring divided attention could be more strongly determined by neuropsychological probes of fluid intelligence. The findings of this study indicate that - apart from hearing impairment - cognitive aspects account for the typical difficulties of older listeners in a multi-speaker setting. Our results are discussed in the context of evidence showing that frontal lobe functions in terms of working memory and fluid intelligence generally decline with age.