Investigation of a Cognitively-Focussed Hearing Aid Setting on Hearing and Cognitive Performance in Experienced Elderly Hearing Aid Users

Abstract

Introduction: The prevalence of hearing loss is high in older adults. Hearing aids are a common rehabilitative option for improving speech audibility and intelligibility. The evidence is emerging to show improved cognitive functioning in hearing-impaired older adults using hearing aids. Digital hearing aid signal processing strategies have shown variable benefits in individuals which can be attributed to individual differences in hearing loss and cognitive capacity. The interaction between hearing aids and cognition is, therefore, complex and research regarding the immediate effects of hearing aid amplification approaches on decreasing cognitive load have been limited. Objective: To investigate whether a cognitively-focussed hearing aid setting (CogniAid) will improve hearing and cognition more than current, standard practice in experienced elderly hearing aid users. Methods: Twenty experienced hearing aid users (aged 65 or over) participated in the repeated measures study over two sessions. All participants were bilaterally fitted with Phonak Audéo B90 receiver-in-the-ear hearing aids, which were programmed to either the CogniAid or standard hearing aid settings in a counterbalanced order. The CogniAid hearing aid setting received linear signal processing and output limiting compression, while the standard hearing aid setting received wide dynamic range compression signal processing. Objective measures of hearing and cognition were collected for the unaided and the two aided conditions, using the QuickSIN™ test to measure speech intelligibility in noise and the NIH Toolbox® to measure speech intelligibility in quiet, working memory and episodic memory. For each aided condition, subjective rating scales were used to evaluate the perceptual aspects of sound quality. Results: Repeated measures ANOVA revealed significantly lower SNR loss scores in the QuickSIN™ test, indicating better speech intelligibility in noise with the CogniAid hearing aid setting compared to both the standard hearing aid setting and the unaided condition. For the NIH Toolbox® picture vocabulary test, participants performed significantly better with the CogniAid hearing aid setting compared to the unaided condition, but there were no differences in performance when compared to the standard hearing aid setting. There were no statistically significant differences between the standard hearing aid setting and the unaided condition in any of the hearing or cognitive tests. There were no statistically significant differences between the two aided conditions on any of the subjective measures of sound quality for speech in quiet or speech in noise. Conclusion: The CogniAid improved speech intelligibility in noise but attempts to determine whether the CogniAid hearing aid setting relieved cognitive load and reduced listening effort compared to the standard hearing aid setting were inconclusive. Future research should investigate the use of alternative cognitive assessment tools and field trials to check if the findings differ.