If you have some type of hearing impairment, do you ever find that listening to people speak is work, and that you need to try hard to understand what people say? You are not alone. The feeling that listening and understanding is tiring work is typical among individuals with hearing loss – even those that wear hearing aids.

Unfortunately, the repercussions of this sensation may not be limited to loss of hearing function; it may also be related to declines in cognitive abilities. In the latest studies, researchers have discovered that hearing loss substantially raises your chances of developing Alzheimer’s and dementia.

A 16-year research study of this link from the Johns Hopkins School of Medicine included 639 participants between the ages of 36 and 90. The data indicated that 58 study volunteers – 9 percent – had developed dementia and 37 – 6% – had developed Alzheimer’s. The degree of hearing loss was positively correlated with the likelihood of developing either condition. For every ten decibel further hearing loss, the risk of developing dementia increased 20%.

A different 16-year research study with 1,984 participants revealed a similar connection between dementia and hearing loss, but also identified noticeable decline in cognitive function in the hearing-impaired. In comparison to individuals with normal hearing, those with hearing impairment developed memory loss 40 percent faster. A vital, but disconcerting, conclusion in each of the two studies was that the negative cognitive effects were not diminished by using hearing aids. A number of hypotheses have been put forth to explain this apparent relationship between hearing loss and loss of cognitive performance. One of these explanations is related to the question that began this article, about having to work harder to hear; this has been termed cognitive overload. The cognitive overload theory suggests that the hearing-impaired individual expends so much brain energy trying to hear, that the brain is tired and has a diminished capacity to comprehend and absorb verbal information. Maintaining a two-way conversation requires comprehension. A lack of understanding causes conversations to break down and might bring about social isolation. Another idea is that neither hearing loss nor dementia cause the other, but that they’re both linked to an as-yet-undiscovered disease mechanism – possibly vascular, possibly genetic, possibly environmental – that causes both.

Although the person with hearing impairment probably finds these study results dismaying, there is a bright side with valuable lessons to be derived from them.If you wear hearing aids, visit your audiologist regularly to keep them fitted, adjusted, and programmed correctly, so that you are not straining to hear. The less effort used in the mechanics of hearing, the more brain power available for comprehension. Also, if hearing loss is related to dementia, knowing this may bring about interventional techniques that can avert its development.