If you have some type of hearing loss, 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 feeling that listening and understanding is demanding work is common among people with hearing loss – even those that use hearing aids.

As though that was not bad news enough, it may not be just your hearing that is impacted, but also cognitive functions. Hearing loss substantially raises your chance of contracting dementia or Alzheimer’s according to the latest research studies.

A 16-year study of this link from the Johns Hopkins School of Medicine included 639 volunteers between the ages of 36 and 90. At the conclusion of the study, scientists found that 58 people (9 percent) had been identified as suffering from dementia, and that 37 participants (5.8%) had developed Alzheimer’s. The degree of hearing loss was positively correlated with the odds of developing either condition. For every ten decibel additional hearing loss, the risk of developing dementia went up by 20 percent.

A different study of 1,984 people, also 16 years long, demonstrated 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 study. Compared to participants with normal hearing, those with hearing impairment developed memory loss 40% faster. An even more surprising conclusion in both studies was that the connection between hearing loss and dementia held true even if the individuals wore hearing aids.

The link between hearing loss and loss of cognitive abilities is an active area of research, but scientists have proposed a few theories to explain the results seen to date. One hypothesis is associated with the question at the beginning of this article, and has been given the name cognitive overload. The theory is that among the hearing-impaired, the brain tires itself out so much working to hear that it cannot concentrate on the meaning of the speech 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 dementia nor hearing loss cause the other, but that they’re both linked to an as-yet-undiscovered disease mechanism – possibly vascular, possibly genetic, possibly environmental – which causes both.

Although these study results 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 hearing specialists regularly to keep the aids perfectly fitted and tuned, so that we’re not constantly straining to hear. If you don’t have to work so hard to hear, you have greater cognitive capacity to comprehend what is being said, and remember it. And, if it ends up that loss of hearing is an early indicator of dementia, discovering the hearing loss early might allow for early intervention to prevent the development.