Nearly two-thirds of Americans over 70 have some degree of hearing loss, according to the first national estimates published Sunday.
The new survey comes as experts with the U.S. Preventive Services Task Force are updating their recommendations on screening for hearing loss in people age 50 and older. It also comes a week after a different study, by another team, showed that one in nine people aged 45-54 have some degree of hearing loss, as do more than 90 percent of those over 80.
The new research shows fewer than one in five of those older than 70 use hearing aids.
"We are increasingly realizing that hearing loss is incredibly important as we age," said study author Dr. Frank R. Lin, an ear surgeon at Johns Hopkins University in Baltimore. His findings appear in the Journal of Gerontology: Medical Sciences.
"The big thing we really need to figure out is, what is the impact of hearing loss in older adults?" Lin told Reuters Health.
In a study out earlier this month, his team found that elderly people who are hard of hearing also have higher rates of dementia. It's still unclear, however, whether there's any cause-effect relationship at work -- nor whether dementia can be fixed with hearing aids.
So far, Lin said, hearing loss has been considered much less important in old people than in kids and adolescents. For instance, most U.S. insurance companies don't cover hearing aids for the elderly, despite doing so for kids.
A pair of hearing aids may cost as much as $4,000.
In a review of studies published today in the Annals of Internal Medicine, the U.S. Preventive Services Task Force found little evidence of harm from hearing aids. They conclude that there is good reason to believe that the devices do improve quality of life.
For the new study, Lin and colleagues used data on 717 people, whose hearing had been tested in 2005 and 2006 as part of the National Health and Nutritional Examination Survey.
More than a third had mild hearing loss, which would make it difficult to follow a conversation in a noisy restaurant. A quarter had moderate hearing loss and less than one percent had severe problems.
"The total number of people with hearing loss is going up," said Lin, "but that's primarily driven by people living longer."
The absolute risk, he added, in fact appears to have decreased slightly.
Compared to white people, blacks had only about a third the chance of losing their hearing. Lin said the reasons aren't fully understood, but are probably tied to the higher levels of the melanin pigment in blacks, which may protect their inner ear from free radicals and other chemical damage.
Lin's team is now studying the effects of giving older people hearing aids.
"There's no doubt they improve communication skills and quality of life," he said. "But do they improve bigger outcomes, such as cognition and social isolation? We don't really know."