Relating Working Memory to Compression Parameters in Clinically Fit Hearing Aids

Purpose: Several laboratory studies have demonstrated that working memory may influence response to compression speed in controlled (i.e., laboratory) comparisons of compression. In this study, the authors explored whether the same relationship would occur under less controlled conditions, as might occur in a typical audiology clinic. Method: Participants included 27 older adults who sought hearing care in a private practice audiology clinic. Working memory was measured for each participant using a reading span test. The authors examined the relationship between working memory and aided speech recognition in noise, using clinically fit hearing aids with a range of compression speeds. Results: Working memory, amount of hearing loss, and age each contributed to speech recognition, but the contribution depended on the speed of the compression processor. For fast- acting compression, the best performance was obtained by patients with high working memory. For slowacting compression, speech recognition was affected by age and amount of hearing loss but was not affected by working memory. Conclusions: Despite the expectation of greater variability from differences in compression implementation, number of compression channels, or attendant signal processing, the relationship between working memory and compression speed showed a similar pattern as results from more controlled, laboratory- based studies.