For people reading this who have suffered some form of hearing loss, do you ever find yourself having to work really hard to understand what’s being said to you or around you? This is a sensation that happens even to people wearing hearing aids, because in order for them to work well you need to have them fitted and tuned correctly, and then get used to wearing them.
As though that wasn’t bad enough, it may not be just your hearing that is affected, but also cognitive functions. In recent studies, researchers have found that hearing loss drastically raises your chances of contracting dementia and Alzheimer’s.
One particular research study was conducted by the Johns Hopkins School of Medicine on 639 volunteers between the ages of 36 and 90 over a period of sixteen years. At the conclusion of the study, investigators found that 58 people (9 percent) had been identified as having dementia, and that 37 of them (5.8%) had developed Alzheimer’s disease. The degree of hearing loss was positively correlated with the probability of developing either condition. For every 10 decibel additional hearing loss, the risk of developing dementia went up by 20%.
Another 16-year research study with 1,984 participants revealed a very similar relationship between dementia and hearing loss, but also identified noticeable degradation in cognitive function in the hearing-impaired. Compared to individuals with normal hearing, those with hearing impairment developed memory loss 40% faster. A far more startling conclusion in both studies was that the link between hearing loss and dementia held true even if the participants wore hearing aids.
Scientists have offered several theories to explain the connection between hearing loss and loss of cognitive abilities. One explanation is based on the question at the start of this article, and has been given the name cognitive overload. The theory is that among the hearing-impaired, the brain exhausts itself so much trying to hear that it cannot concentrate on the meaning of the sounds that it is hearing. Having a two-way discussion requires comprehension. An absence of understanding causes conversations to break down and may result in social isolation. A second theory is that neither dementia nor hearing loss is the cause of the other, but that both are caused by an unknown mechanism that could be environmental, vascular or genetic.
Despite the fact that these study outcomes are a little depressing, there is hope that comes from them. For those of us who wear hearing aids, these outcomes serve as a reminder to see our audiologists on a regular basis to keep the hearing aids perfectly fitted and tuned, so that we’re not continually straining to hear. If you do not have to work as hard to hear, you have greater cognitive capacity to comprehend what is being said, and remember it. Also, if the 2 conditions are connected, early detection of hearing impairment might at some point lead to interventions that could avoid dementia.