Nov. 14, 2011 at 4:36 PM ET
Nearly one in five Americans has significant hearing loss, far more than previously estimated, a first-ever national analysis finds.
That means more than 48 million people across the United States have impairments so severe that it’s impossible for them to make out what a companion is saying over the din of a crowded restaurant, said Dr. Frank Lin, author of a new study published in the latest issue of the Archives of Internal Medicine.
“It’s pretty jaw-dropping how big it is,” said Lin, an assistant professor of otolaryngology and epidemiology at the Johns Hopkins School of Medicine.
Previous estimates had pegged the number affected by hearing loss at between 21 million and 29 million.
Lin and other researchers were surprised at the magnitude of the problem, but the significance of the findings goes beyond the “wow” factor, he said.
That’s because other studies have shown that hearing decline is often accompanied by losses in cognition and memory. Further, Lin said, some studies have associated hearing loss with a greater risk of dementia.
Lin’s study is the first to look at the hearing loss in a national sample of Americans aged 12 and older who have actually had their hearing tested. Earlier studies were smaller or depended on people’s self-reports of hearing loss.
For the new study, Lin and his colleagues analyzed data collected as part of the National Health and Nutritional Examination Surveys (NHANES), a research program that has periodically gathered information from thousands of Americans since 1971.
Using the World Health Organization’s definition for hearing loss as not being able to hear sounds of 25 decibels or less in the frequencies for speaking, the researchers found that about 30 million Americans, or nearly 13 percent of the population, had hearing loss in both ears.
That number jumped to about 48 million, or more than 20 percent of the population, by adding people with loss in just one ear.
Many people begin to lose their hearing in their 50s, Lin said. And the process is so gradual that they barely notice. That’s one of the reasons earlier studies found lower numbers of people with hearing loss, Lin said.
“Young people will come in with hearing loss from an infection and they feel so impaired that they can’t do their jobs,” Lin said. “But a lot of times, their hearing loss isn’t as bad as what we see in someone in their 60s who has learned to live with it.”
Because of the association with memory problems, loss of cognition and dementia, Lin would like to see more middle-aged people and seniors getting tested -- and treated -- for hearing loss. Now, the problem is often ignored, he said.
“If a 10-year-old has mild-to-moderate hearing loss, universally clinicians, insurers, and society say we’ve got to treat it,” Lin said. “But if you have the same hearing loss in someone who is 60, universally you get a shrug. That person still has to go to board meetings and hear people over dinner. But we don’t think it’s important for him to get treated.”
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