For those of you who’ve suffered some type of hearing impairment, do you ever find yourself having 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 normal even among people who use hearing aids, because they must be fitted and tuned properly to work well, and you need to become used to using them.
Sadly, the consequences of this sensation might not be restricted to loss of hearing function; it may also be linked with declines in cognitive function. Contemporary studies have established that there is a solid relationship between hearing loss and your risk of contracting Alzheimer’s and dementia.
One particular study was conducted by the Johns Hopkins School of Medicine on 639 individuals ages 36 to 90 over a period of 16 years. At the end of the study, scientists found that 58 participants (9%) had been identified as suffering from dementia, and that 37 of them (5.8%) had developed Alzheimer’s. Researchers found that for every 10 decibels of hearing loss, the participants’ odds of developing dementia increased by 20 percent; the more significant the hearing loss, the greater their chance of dementia.
In a related research study, evaluating 1,984 participants, investigators observed a similar association between hearing loss and dementia, but they also found that the hearing-impaired suffered measurable decreases in their cognitive functions. The hearing-impaired experienced loss of thinking capacity and memory 40 percent faster than those with normal hearing. A far more astonishing finding in both research studies was that the connection between hearing loss and dementia held true even if the individuals wore hearing aids.
Various hypotheses have been put forth to explain this seeming connection between hearing loss and loss of cognitive performance. One hypothesis is related to the question at the start of this article, and has been given the name cognitive overload. Some researchers believe that if you are hearing-impaired, your brain exhausts itself just trying to hear that it has a reduced capacity to comprehend what is being said. This may bring about social isolation, which has been linked to dementia risk in other studies. 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 both the consequence of a third mechanism. This unknown disorder could be vascular, environmental or genetic in nature.
However dismal these study results may sound, there are lessons to be learned from them. For those people who wear hearing aids, these results serve as a reminder to visit our audiologists on a regular basis to keep the aids properly fitted and programmed, so that we aren’t continually straining to hear. The less energy expended in the mechanics of hearing, the more brain capacity available for comprehension. Also, if loss of hearing is linked to dementia, knowing this might lead to interventional methods that can avert its onset.