Do you have hearing loss? If so, do you occasionally find that it seems like work just to understand what the people around you are saying? This is a phenomenon that happens even to people wearing hearing aids, because in order for them to perform well you have to have them fitted and tuned properly, and then get used to using them.
Unfortunately, the repercussions of this phenomenon might not be limited to hearing loss; it may also be related to declines in cognitive abilities. Hearing loss significantly increases your odds of developing dementia or Alzheimer’s according to recent research studies.
One particular research study was conducted by the Johns Hopkins School of Medicine on 639 individuals ages 36 to 90 16-year period. The researchers found that at the end of the research project, 58 of the volunteers (9%) had developed dementia, and 37 (5.8 percent) had been diagnosed with Alzheimer’s disease. The degree of hearing loss was positively correlated with the probability of developing either disorder. For every 10 decibel additional hearing loss, the risk of developing dementia increased 20 percent.
A different 16-year research study with 1,984 participants found a similar association between hearing loss and dementia, but also observed noticeable decline in cognitive abilities in the hearing-impaired. The hearing-impaired participants showed reduced thinking capacity and memory loss 40 percent faster than individuals with normal hearing. An even more surprising conclusion in each of the two studies was that the connection between dementia and hearing loss held true even if the participants wore hearing aids.
The link between loss of hearing and loss of cognitive abilities is an open area of research, but scientists have suggested a few theories to explain the results observed to date. One hypothesis is related to 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 exhausts itself so much working to hear that it can’t focus on the meaning of the speech that it is hearing. The ensuing lack of comprehension can cause social isolation, a factor that has been shown in other studies to lead to dementia. A different line of thought, hypothesizes that dementia and hearing are not causally related to each other at all. Rather the theory states that they are each the consequence of a third mechanism. This unknown disorder could be genetic, environmental or vascular in nature.
Although the individual with hearing impairment probably finds these study results depressing, there is a bright side with useful lessons to be derived from them.For people who use hearing aids, it’s important to have your hearing aids re-fitted and adjusted on a regular basis. You shouldn’t make you brain work harder than it has to work in order to hear. The less you have to strain, the more cognitive capacity your brain has in reserve to understand what is said, and remember it. Also, if the two symptoms are connected, early detection of hearing loss might at some point lead to interventions that could avoid dementia.