Effects of Age, Hearing Loss and Cognition on Discourse Comprehension and Speech Intelligibility Performance

Discourse comprehension requires listeners to interpret the meaning of an incoming message, integrate the message into memory and use the information to respond appropriately. Discourse comprehension is a skill required to effectively communicate with others in real time. The overall goal of this research is to determine the relative impact of multiple environmental and individual factors on discourse comprehension performance for younger and older adults with and without hearing loss using a clinically feasible testing approach. Study 1 focused on the impact of rapid speech on discourse comprehension performance for younger and older adults with and without hearing loss. Study 2 focused on the impact of background noise and masker type on discourse comprehension performance for younger and older adults with and without hearing loss. The influences of cognitive function and speech intelligibility were also of interest. The impact of these factors was measured using a self-selection paradigm in both studies. Listeners were required to self-select a time-compression ratio or signal-to-noise ratio (SNR) where they could understand and effectively answer questions about the discourse comprehension passages. Results showed that comprehension accuracy performance was held relatively constant across groups and conditions, but the time-compression ratios and SNRs varied significantly. Results in both studies demonstrated significant effects of age and hearing loss on the self-selection of listening rate and SNR. This result suggests that older adults are at a disadvantage for rapid speech and in the presence of background noise during a discourse comprehension task compared to younger adults. Older adults with hearing loss showed an additional disadvantage compared to older normal-hearing listeners for both difficult discourse comprehension tasks. Cognitive function, specifically processing speed and working memory, was shown to predict self-selected time-compression ratio and SNR. Understanding the effects of age, hearing loss and cognitive decline on discourse comprehension performance may eventually help mitigate these effects in real world listening situations

Short-term adaptation to accented English by younger and older adults

This study examined the effects of age and hearing loss on short-term adaptation to accented speech. Data from younger and older listeners in a prior investigation [Gordon-Salant et al. (2010). J. Acoust. Soc. Am. 128, 444–455] were re-analyzed to examine changes in recognition over four administrations of equivalent lists of English stimuli recorded by native speakers of Spanish and English. Results showed improvement in recognition scores over four list administrations for the accented stimuli but not for the native English stimuli. Group effects emerged but were not involved in any interactions, suggesting that short-term adaptation to accented speech is preserved with aging and with hearing loss