Predicting Benefit from a Signal-to-Noise Ratio Hearing Aid Intervention Based on Individual Differences in Hearing and Cognition within an Older Adult Population

Abstract

Difficulty perceiving speech in noise is a common complaint for individuals with hearing loss, even while wearing hearing aids. Current clinical test measures are limited in their ability to predict potential benefit from hearing aid interventions such as directionality. If speech in noise interventions provide an SNR boost, then the slope of a speech in noise psychometric function or rate of improvement could help to predict the corresponding intelligibility benefit due to an improved SNR. Recent research highlights the association between cognition, hearing loss, and speech perception in noise. We hypothesized that the rate of improvement, which is likely associated with both auditory and cognitive factors, may be a source of the variable benefit observed from directionality. Our study revealed that more intelligibility benefit due to hearing aid directionality was measured in a listening condition which resulted in steeper rate of improvement (babble background) than a listening condition which resulted in a shallower rate of improvement (competing speech). Additionally, the rates of improvement between our most relevant SNRs were significantly associated with directional benefit. These results confirm that the rate of improvement for a given range of SNRs could help in predicting potential benefit from an SNR intervention within a hearing loss population. Our results confirmed that hearing loss severity of negatively associated with rate of improvement and working memory capacity was positively associated with rate of improvement. Our findings support the involvement of cognition in addition to the auditory pathway for the perception of degraded speech signals within a population with hearing loss. Measuring cognitive factors such as working memory capacity could improve our understanding of patient variability for aided speech in noise outcomes and provide a patient-specific approach to hearing loss interventions.