The Connection Between Hearing Loss and Cognitive Decline
“When we hear, we assume we're using our ears, but we're not. 'Hearing' actually takes place in the brain,” says Brandy McCoy, Hearing Instrument Specialist with Absolute Audio. This is why hearing loss has such an impact on brain function; it causes the areas of the brain that respond to sound to become reorganized.
Several studies have cropped up over the last few years, specifically out of the Cochlear Center for Hearing and Public Health at Johns Hopkins University. One study found that hearing loss is “associated with accelerated cognitive decline in older adults and that seniors with hearing loss are significantly more likely to develop dementia over time than those who retain their hearing.”
A third Johns Hopkins study revealed a link between hearing loss and accelerated brain tissue loss. This tissue loss, or “shrinkage,” occurs as a natural part of aging, but the researchers found that for older adults with hearing loss, the brain tissue loss happens faster than it does for those with normal hearing. This finding “adds to a growing list of health consequences associated with hearing loss, including increased risk of dementia, falls, hospitalizations, and diminished physical and mental health overall.”
There is also a strong relationship between hearing acuity and memory. Hearing loss left unaddressed not only affects the listener’s ability to hear sound accurately, it also affects higher-level cognitive function. It becomes much harder for the listener to accurately process the auditory information and make sense of it all.
The research in this field is still new, but hearing health is increasingly becoming a part of the discussion surrounding cognitive decline and dementia, which is already an important public health concern.
By the time someone is showing signs of dementia, the damage to the brain has already been done. The goal is to prevent the decline from occurring in the first place. According to Dr. Jennifer Deal of the Cochlear Center, one of the only later-life risk factors that could potentially delay cognitive decline is better hearing health. In fact, it has been estimated that up to 35 percent of dementia could be prevented due to modifiable risk factors, the biggest of which is hearing loss (Lancet Commission on Dementia Prevention, 2017).
So many people suffer from hearing loss, which causes these statistical percentages to be so high. The National Institute on Deafness and Other Communication Disorders (NIDCD) says approximately 15 percent of American adults (37.5 million) aged 18 and over report some trouble hearing. About 2 percent of adults aged 45 to 54 have disabling hearing loss. The rate increases to 8.5 percent for adults aged 55 to 64. Nearly 25 percent of those aged 65 to 74, and 50 percent of those who are 75 and older, have disabling hearing loss. Men are almost twice as likely as women to have hearing loss among adults aged 20 to 69.
“Anyone over the age of 55 should be having their hearing screened once a year to assess their risk,” says McCoy. Studies are continually being conducted in an attempt to find answers to these pressing public health concerns. In the meantime, if you have any concerns about your hearing, talk with your hearing healthcare professional.