Although the specific reasons are not yet clear, what is observable is that there is a link of some kind between untreated hearing loss and the onset of dementia.
Several long-term studies — including two prominent ones affiliated with Johns Hopkins Medicine — have been carried out over the last decade. They have tracked the cognitive abilities of older people with varying levels of hearing capabilities. There appears to be a clear correlation between hearing loss issues coinciding with an erosion of cognitive health.
Some theories include: limited audiological input robs the brain of needed activity — as if the exercise routine of the brain had been severely reduced — and results in brain tissue loss; that the effort the brain must endure in deciphering garbled sounds over a number of years overwhelms brain function; or that there is some yet undiscovered common pathology that leads to both hearing loss and dementia.
Yet another theory is that hearing loss leads to social isolation, since communicating with other people becomes harder and harder. It has already been established that loneliness is a risk factor for developing cognitive disorders.
This last theory makes it clear that early discovery and intervention regarding hearing loss is vital. Treatments — such as hearing aids — may very well lessen whatever link there is between hearing loss and dementia. It’s very possible that by continuing more “normal” sound input to the brain, hearing aids prevent the deterioration of brain function.
These findings and theories point in one clear direction: that hearing should be routinely tested — starting in middle age as part of annual physical checkups — and issues treated as quickly as possible. It’s clear that hearing loss does the brain no good.