Do you have hearing problems? If so, do you sometimes find that it feels like work just to understand what the people near you are saying? This is a sensation that happens even to people wearing hearing aids, because in order for them to perform well you need to have them fitted and tuned correctly, and then get used to using them.
This frequent phenomenon may affect more than your ability to hear; it may also influence your cognitive abilities and your memory. In recent studies, scientists have discovered that hearing loss substantially raises your chances of contracting Alzheimer’s and dementia.
One of these studies, conducted at Johns Hopkins School of Medicine, followed 639 people ages 36 to 90, for a total of 16 years. The scientists found that at the conclusion of the study, 58 of the participants (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 participants’ chances of developing dementia increased by 20 percent; the greater the degree of hearing loss, the higher their risk of dementia.
Another 16-year research study with 1,984 participants found a similar connection between hearing loss and dementia, but also identified noticeable decline in cognitive function in the hearing-impaired. The hearing-impaired individuals developed reduced thinking capacity and memory loss 40% faster than participants with normal hearing. A vital, but depressing, conclusion in each of the two studies was that the adverse cognitive effects were not diminished by using hearing aids. The connection between hearing loss and loss of cognitive abilities is an open area of inquiry, but scientists have proposed a few hypotheses to explain the results seen to date. Scientists have coined the term cognitive overload in conjunction with one particular hypothesis. The theory is that among the hearing-impaired, the brain tires itself out so much working to hear that it can’t focus on the meaning of the sounds that it is hearing. The resulting lack of understanding can cause social isolation, a factor that has been demonstrated in other studies to cause dementia. 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 genetic, vascular, or environmental.
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 visit our audiologists on a regular basis to keep the aids perfectly adjusted and tuned, so that we’re not continually straining to hear. The less work expended in the mechanics of hearing, the more brain power available for comprehension. Also, if the two conditions are linked, early detection of hearing impairment might eventually lead to interventions that could avoid dementia.