Researchers are studying the effects of hearing loss on cognition. Specifically, the researchers of this study investigated if self-reported hearing loss was associated with cognitive decline. The study broke the subjects into three categories:
- Subjects with “major hearing loss” — 137 subjects
- Subjects with moderate hearing loss, defined in this study as having difficulty following the conversation when several persons talk at the same time or in a noisy background — 1139
- Subjects with no hearing trouble — 2394 subjects
Cognitive decline was measured using the Mini Mental State Examination (MMSE), administered over the course of 25 years. Here are the conclusions following the 25-year study:
- Self-reported hearing loss was significantly associated with lower baseline MMSE scores and greater decline during the 25-year follow-up period, independent of age, sex, and education.
- There is a difference in the rate of cognitive decline, as measured by the MMSE score over a 25-year period, between the subjects with hearing loss who did not use hearing aids and the control subjects who did not have hearing loss.
- Subjects with hearing loss who used a hearing aid had no difference in cognitive decline compared to the control subjects who did not have hearing loss.
In other words, subjects in the study show that hearing loss is independently associated with accelerated cognitive decline in older adults, supporting prior research, except that this study involved a large number of participants over a long period — two strengths of the study.
There was an opposite trend for subjects who reported hearing loss and wore hearing aids. Contrary to the subjects with hearing loss who did not wear hearing aids, the subjects who wore hearing aids had similar rates of cognitive decline as those with hearing loss.
Hearing loss has long been clinically associated with depressive symptoms and greater social isolation. This study is one of growing support for the hypothesis that depressive symptoms and social isolation may be the mediating factor between untreated hearing loss and cognitive decline. It is currently postulated that hearing aid use, in this and other studies, restores the ability to effectively communicate, improve mood, increase social interactions, and enable participation in cognitively stimulating situations, potentially slowing cognitive decline.
Sharon Macner, Au.D. Doctor of Audiology, Champlain Valley Audiology, PLLC Plattsburgh, NY Amieva, H., Ouvard, C., Giulioli, C. et al. Self-Reported Hearing Loss, Hearing aids, and cognitive decline in elderly adults: A 25 year study. Journal of the American Geriatrics Society. 2015; 63: 2099–2104.