Research performed at Johns Hopkins University has revealed a correlation between hearing loss and cognitive decline. A 2013 study with 2,000 older adults (average age: 77) was tracked for a period of six years. Those who began the study with the worst hearing loss, hearing loss that interfered with daily conversation, were 24 percent more likely to see a decline in cognitive ability compared to individuals with normal hearing.
Lin and Albert (2014)’s paper proposed potential mechanisms that underlie this association, including cognitive load, brain structure, and decreased social engagement. Cognitive load refers to hearing loss taxing the brain’s resources that could otherwise be available for memory and concentration. Brain structure is affected when hearing loss yields reduced auditory stimulation. Lastly, decreased social engagement may be due to the social isolation many individuals with hearing loss experience. Insufficient socialization has been shown to accelerate cognitive decline.
French researchers, however, undertook a study involving 3,670 participants over 25 years, and they found that patients who treated their hearing loss with hearing aids attenuated their rates of cognitive decline. The patients who wore hearing devices experienced cognitive decline at a rate comparable to the control (normal-hearing) group, while the patients who did not treat their hearing loss had significantly lower scores on a test used to measure cognitive performance.