For those of you who’ve suffered some type of hearing loss, do you ever find yourself needing to work really hard to understand what is being said to you or around you? This experience of having to work to understand people is common even among people who use hearing aids, because the aids need to be fitted and programmed properly to work right, and you need to get acclimated to wearing them.
This common sensation may impact more than your hearing; it might also impact your memory and your cognitive abilities. Contemporary studies have indicated that there is a solid connection between hearing loss and your chance of contracting dementia and Alzheimer’s.
One of these studies, conducted at Johns Hopkins School of Medicine, analyzed 639 people between the ages of 36 and 90, for a total of 16 years. The scientists found that at the conclusion of the study, 58 of the volunteers (9 percent) had developed dementia, and 37 (5.8 percent) had been diagnosed with Alzheimer’s disease. They found that for every ten decibels of hearing loss, the individuals’ odds of developing dementia went up by 20%; the greater the hearing loss, the higher their risk of dementia.
A separate study of 1,984 people, also sixteen years in duration, showed comparable results linking hearing loss and dementia. In this second study, investigators also found degradation of cognitive functions among the hearing-impaired over the course of the data gathering. They experienced loss of thinking capacity and memory 40 percent faster than those with normal hearing. A crucial, but disturbing, conclusion in each of the two studies was that the negative cognitive effects were not diminished by wearing hearing aids. A number of hypotheses have been proposed to explain this apparent link between hearing loss and loss of cognitive performance. One explanation is related to 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 working to hear that it cannot concentrate on the meaning of the sounds that it is hearing. This may lead to social isolation, which has been connected to dementia risk in other studies. Another idea is that neither hearing loss nor dementia cause the other, but that they’re each linked to an as-yet-undiscovered pathological mechanism – possibly vascular, possibly genetic, possibly environmental – which causes both.
Despite the fact that these study results are a little depressing, there is hope that comes from them. For people who wear hearing aids, it is essential to have your aids tuned and re-programmed on a consistent basis. You shouldn’t make you brain work harder than it has to work in order to hear. If you do not have to work so hard to hear, you have greater cognitive power to comprehend what is being said, and remember it. Also, if the 2 symptoms are linked, early detection of hearing loss might eventually lead to interventions that could avoid dementia.