How Spoken Language Comprehension is Achieved by Older Listeners in Difficult Listening Situations.

Background/study Context: Comprehending spoken discourse in noisy situations is likely to be more challenging to older adults than to younger adults due to potential declines in the auditory, cognitive, or linguistic processes supporting speech comprehension. These challenges might force older listeners to reorganize the ways in which they perceive and process speech, thereby altering the balance between the contributions of bottom-up versus top-down processes to speech comprehension.

Methods: The authors review studies that investigated the effect of age on listeners' ability to follow and comprehend lectures (monologues), and two-talker conversations (dialogues), and the extent to which individual differences in lexical knowledge and reading comprehension skill relate to individual differences in speech comprehension. Comprehension was evaluated after each lecture or conversation by asking listeners to answer multiple-choice questions regarding its content.

Results: Once individual differences in speech recognition for words presented in babble were compensated for, age differences in speech comprehension were minimized if not eliminated. However, younger listeners benefited more from spatial separation than did older listeners. Vocabulary knowledge predicted the comprehension scores of both younger and older listeners when listening was difficult, but not when it was easy. However, the contribution of reading comprehension to listening comprehension appeared to be independent of listening difficulty in younger adults but not in older adults.

Conclusion: The evidence suggests (1) that most of the difficulties experienced by older adults are due to age-related auditory declines, and (2) that these declines, along with listening difficulty, modulate the degree to which selective linguistic and cognitive abilities are engaged to support listening comprehension in difficult listening situations. When older listeners experience speech recognition difficulties, their attentional resources are more likely to be deployed to facilitate lexical access, making it difficult for them to fully engage higher-order cognitive abilities in support of listening comprehension.