If you have some form of hearing impairment, do you ever find that listening to people talk is work, and that you need to try really hard to understand what people say? You are not alone. The sensation that listening and understanding is tiring work is typical among people with hearing impairment – even those that wear hearing aids.
As though that was not bad enough, it may not be just your ability to hear that is impacted, but also cognitive abilities. The latest research studies have established that there is a strong association between hearing loss and your risk of contracting Alzheimer’s and dementia.
One of these research studies, conducted at Johns Hopkins School of Medicine, analyzed 639 people between the ages of 36 and 90, for a period of sixteen years. The data showed that 58 study participants – 9% of the total – had developed dementia and 37 – 6 percent – had developed Alzheimer’s disease. They found that for every ten decibels of hearing loss, the individuals’ odds of developing dementia increased by 20 percent; the more significant the degree of hearing loss, the greater their chance of dementia.
A separate research study of 1,984 people, also sixteen years in duration, demonstrated comparable results linking hearing loss and dementia. In this second research study, investigators also found decline of cognitive capabilities among the hearing-impaired over the course of the study. Compared to participants with normal hearing, those with hearing loss developed memory loss 40% faster. A pivotal, but depressing, conclusion in both studies was that the adverse cognitive effects were not diminished by wearing hearing aids. The link between hearing loss and loss of cognitive functions is an active area of inquiry, but researchers have proposed a few hypotheses to explain the results seen thus far. One of these explanations relates to the question that began this article, about needing to work harder to hear; this has been called cognitive overload. Some researchers suspect that if you are hearing-impaired, your brain tires itself out so much just trying to hear that it has a reduced capacity to understand what is being said. The resulting lack of understanding may cause social isolation, a factor that has been demonstrated in other research studies to lead to dementia. Another idea is that neither dementia nor hearing loss cause the other, but that they’re both related to an as-yet-undiscovered pathological mechanism – possibly vascular, possibly genetic, possibly environmental – that causes both.
Despite the fact that these study outcomes are a little dismaying, there is hope that comes from them. For those of us who wear hearing aids, these outcomes serve as a reminder to see our hearing specialists on a regular basis to keep the aids properly fitted and tuned, so that we aren’t constantly straining to hear. If you don’t have to work so hard to hear, you have greater cognitive power to understand what is being said, and remember it. Also, if loss of hearing is linked to dementia, knowing this might lead to interventional methods that can prevent its onset.