Sometimes older people who appear to be slipping mentally simply can't hear. When fitted for a hearing aid, their cognition returns to normal. But sometimes the opposite is the case, and people who can't hear well really do decline mentally faster than people with normal hearing, according to Dr. Frank Lin, a professor at the Johns Hopkins Center on Aging and Health.
In a recent study of nearly 2,000 older people published in JAMA Internal Medicine, Lin found that those with hearing loss — about half the group — experienced 30-40 percent greater cognitive decline per year compared to those with normal hearing. That translated into a 24 percent increase in the risk of cognitive decline or, put another way, people with hearing loss would decline by 5 points on a standard test of memory and cognition in 7.7 years, while people with normal hearing would take 10.9 years to decline as much.
Would getting a hearing aid reduce the risk of cognitive decline?
No one knows for sure, but correcting a hearing problem is always a good idea, according to Lin.
"I think physicians would definitely be justified in recommending comprehensive hearing rehabilitative treatment consisting of hearing aids, training and counseling, and other hearing assistive technologies to ensure that their patients can communicate effectively and remain engaged in life," Lin said. "Whether treatment of hearing loss could reduce cognitive decline and affect cognitive health, though, still remains completely unknown."
The rate of cognitive decline increased with the severity of the hearing loss, according to the study,
Hearing loss increases steadily with age, and is more common than previously believed, according to a 2011 study by Lin and his colleagues published in the Journal of Gerontology. The National Institute on Deafness and Other Communication Disorders (NIDCD) reported that hearing loss affects about 47 percent of those 75 and older, but Lin and his group found that nearly two-thirds of people 70 and older have significant hearing loss.
Age-related hearing loss, known as presbycusis (prez-bee-KYOO-sis), is not like turning down the volume of a radio. The loss generally begins in the higher frequencies, affecting sounds such as birds chirping, and children's voices. As hearing declines, people start to have trouble discriminating consonants, hearing "sat" instead of "cat," for example.
Studies have found that untreated hearing loss may contribute to social isolation as people have more trouble following conversations. One study, by the National Council on Aging, found that people with hearing loss who got hearing aids reported significant improvement in their relationships with friends and family. Also, audiologists predict that the amount of hearing loss in the American population will increase as baby boomers, famous for their youthful fondness for loud music, start to age.
Tom Valeo writes frequently about health matters. He can be reached at firstname.lastname@example.org.