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

Abstract

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.

Notes

¹ These measures were chosen in order to tap two levels of linguistic and cognitive competence. We might expect a vocabulary measure to primarily reflect lexical knowledge and be related to processes involved with lexical access, whereas a reading comprehension test would, in addition to being sensitive to lexical competence, be more likely to tap additional higher-order, modality-independent processes involved in language comprehension, such as working memory, episodic memory, etc. For instance, Nelson-Denny scores and working memory scores have been found to be highly correlated (Schneider, 2011). In future studies, it would be reasonable to investigate the contribution of more specific cognitive and linguistic skills to listening comprehension in these situations.

² Older adults were permitted to have a hearing level in one of their ears at one of the frequencies in the speech range that exceeded 30 dB HL, but was always ≤35 dB HL.

³ For a more complete discussion of why the contribution of vocabulary knowledge to listening comprehension is likely to increase as listening difficulty increases, see Section 4.4 of Avivi-Reich et al. (2014).

⁴ Depending on the listening condition and task, older EL1s need an SNR that is 2-4 dB higher than that required by younger EL1s (Avivi-Reich, Daneman, & Schneider, 2014; Ben-David et al., 2011; Li, Daneman, Qi, & Schneider, 2004; Murphy et al., 2006; Schneider et al., 2000).