If you have some form of hearing loss, do you ever notice that listening to people speak is work, and that you need to try hard to understand what people are saying? This sense of having to try to understand people is common even among people who use hearing aids, because they must be adjusted and tuned properly to work right, and you need to become acclimated to wearing them.
This common sensation may affect more than your hearing; it may also impact your cognitive abilities and your memory. More recent research studies have indicated that there is a strong association between hearing loss and your chance of developing dementia and Alzheimer’s.
One of these studies, from the Johns Hopkins School of Medicine, studied 639 participants ages 36 to 90, for a total of sixteen years. The scientists found that at the conclusion of the research project, 58 of the participants (9 percent) had developed dementia, and 37 (5.8 percent) had been diagnosed with Alzheimer’s. Furthermore, the greater their degree of hearing impairment, the greater was the chance of developing dementia; for every ten decibels of hearing loss, the odds of dementia increased 20%.
A different research study of 1,984 people, demonstrated similar results connecting dementia and hearing loss. In this second research study, researchers 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 impairment developed memory loss 40% faster. In both studies, an even more depressing discovery was that this association was not reduced by using hearing aids.
Several hypotheses have been put forth to explain this apparent link between hearing loss and loss of cognitive ability. Scientists have coined the term cognitive overload in conjunction with one specific theory. The theory is that among the hearing-impaired, the brain tires itself out so much trying to hear that it can’t concentrate on the meaning of the sounds that it is hearing. This may bring about social isolation, which has been linked to dementia risk in other studies. 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.
Although the person with hearing impairment probably finds these study results depressing, there is a good side with important lessons to be extracted from them.For those people who wear hearing aids, these outcomes serve as a reminder to see our hearing instrument specialists on a regular basis to keep the aids properly adjusted and tuned, so that we’re not constantly straining to hear. The less energy expended in the mechanics of hearing, the more brain power available for comprehension. Also, if the two symptoms are connected, early detection of hearing loss might at some point lead to interventions that could avoid dementia.