Longitudinal associations between speech-in-noise deficits and cognitive function over 8 years: the role of hearing aid use and environmental noise exposure

Objective Hearing loss is a potentially modifiable risk factor for dementia, yet questions remain about its impact on cognitive trajectories. Hearing aid use has been proposed as a protective intervention, but findings are mixed. This study examined longitudinal associations between hearing loss, hearing aid use, and cognitive function, and explored the role of environmental noise exposure. Methods We prospectively studied 398 adults aged ≥65 years. Hearing status was assessed using the National Institute of Health Toolbox Words-in-Noise test and Hearing Handicap Inventory for the Elderly. Cognitive function was measured using a Preclinical Alzheimer's Cognitive Composite (PACC). Associations between hearing status, hearing aid use, and cognitive outcomes were evaluated using linear regression and mixed-effects models, adjusting for demographic and environmental covariates. Results Participants had a mean age of 73 years, with 53.5% female and 86.9% identifying as non-Hispanic White. Hearing loss was associated with lower PACC scores cross-sectionally (β = -0.04, p <. 001). Longitudinally, poorer speech-in-noise performance was associated with lower cognitive scores (β = -0.02, p =. 003). Compared to those with normal hearing, participants with hearing loss who did not use hearing aids had lower PACC scores (β = -0.17, p =. 039). Hearing aid users did not differ significantly from the group with normal hearing. However, hearing aid use was not a significant predictor in adjusted models. Environmental noise and neighborhood deprivation were not significant predictors. Discussion Hearing loss was associated with lower cognitive function, however hearing aid use did not significantly influence these trajectories. Further research is warranted to clarify its role.