PP1609 - The Effect of Hearing Loss and Working Memory Capacity on Context Use and Reliance on Context in Older Adults

Objectives:

Older adults often complain of difficulty in communicating in noisy environments. Contextual information is considered an important cue for identifying everyday speech. To date, it has not been clear exactly how context use and reliance on context in older adults are affected by hearing status and cognitive function. The current study examined the effects of semantic context on the performance of speech recognition, recall, perceived listening effort, and noise tolerance, and further explored the impacts of hearing loss and working memory capacity on context use and reliance on context among older adults.

Design:

Fifty older adults with normal hearing and fifty-six older adults with mild-to-moderate hearing loss between the ages of 60 and 95 years participated in this study. A median split of the backward digit span further classified the participants into high and low working memory capacity groups. Each participant performed high- and low-context repeat and recall tests, including a sentence repeat and delayed recall task, subjective assessments of listening effort, and tolerable time under seven signal-to-noise ratios (SNRs). Context use (CU) was calculated as the difference between high-and low-context sentences for each outcome measure. The proportion of context use (PCU) in high-context performance was taken as the reliance on context to explain the degree to which participants relied on context when they repeated and recalled high-context sentences.

Results:

Semantic context helps improve the performance of speech recognition and delayed recall, reduces perceived listening effort, and prolongs noise tolerance in older adults with and without hearing loss. Additionally, the adverse effects of hearing loss on the performance of repeat tasks were more pronounced in low context than in high context, whereas the effects on recall tasks and noise tolerance time were more significant in high context than in low context. Compared to other tasks, the CU and PCU in repeat tasks were more affected by listening status and working memory capacity. In the repeat phase, hearing loss increased older adults’ reliance on the context of a relatively challenging listening environment, as shown by the fact that when the SNR was 0 and -5 dB, the PCU (repeat) of the hearing loss group was significantly greater than that of the normal hearing group, while there was no significant difference between the two hearing groups under the remaining SNRs. Additionally, older adults with low working memory had significantly greater CU and PCU in repeat tasks than those with high working memory, especially at SNRs with moderate task demands.

Conclusions:

Taken together, semantic context not only improved speech perception intelligibility but also released cognitive resources for memory encoding in older adults. Mild-to-moderate hearing loss and low working memory capacity in older adults significantly increased the use and reliance on semantic context, which was also modulated by the level of SNR.