Connection Between Hearing Loss and Cognitive Decline?

Hearing loss affects 30 percent of Americans in their 60s, and that percentage more than doubles for those 70 and older. While it’s one of the most common conditions affecting older adults, some studies indicate that hearing loss can signal an even more serious deterioration—that of cognitive ability.

Hearing Loss and Cognitive Abilities

Older adults typically experience one of two types of hearing loss: peripheral or central. Peripheral hearing loss may occur when the outer or middle ear cannot hear sounds because of physical issues such as fluid in the middle ear, immobility of the middle ear bones or damage to the hair cells or auditory nerve fibers.

Central hearing loss is not related to the inability to hear sounds, but to the inability to comprehend what they mean, with the damage not in the ear but in the brain. In one study, older adults who had central hearing loss also scored lower on a test of their thinking and memory skills, or mild cognitive impairment (MCI). Of the study participants who had central hearing loss, 75 percent also had MCI, in comparison to 60 percent of those with no hearing loss or peripheral hearing loss.

Researchers raised the question of whether MCI was an early form of dementia, and if so, could central hearing loss be an early indicator. Researchers also wondered if hearing loss—whether peripheral or central—contributed to the cognitive decline. Social isolation from an inability to hear well also could lead to cognitive decline, researchers found. In one study, the cognitive abilities of volunteers who had hearing loss and underwent testing declined 30 percent to 40 percent faster than the abilities of volunteers who underwent testing and did not have hearing loss.  

Researchers aren’t sure exactly what the connection is between cognitive decline and hearing loss. In addition to the possibility that cognitive decline is exacerbated by social isolation, decreased hearing could make the brain spend too much time trying to process sound, at the expense of memory and thinking capabilities. Or, there could be common damage that affects both hearing and cognitive ability.

While the cause and correlation are not yet known, here is what we do know: 27 million Americans over 50 suffer some type of hearing loss. However, only 15 percent who need a hearing aid get one. What’s more, studies also show that the use of a hearing aid can slow down the rate of cognitive decline for those with peripheral hearing loss.

There is still much to be learned about the connection between hearing loss and cognitive impairment. But these studies show how important it is not to assume hearing loss is just a part of aging. Instead, talk with your doctor about what can be done to address any differences in your ability to hear or any decrease in cognitive abilities that may come with the loss of hearing.