The reason: Most seniors don't undergo simple screening tests, even though effective treatments could dramatically improve their hearing.
The study, appearing in the April 16 issue of the Journal of the American Medical Association, is based on an analysis of nearly 1,600 research studies published between 1985 and 2001. Researchers concluded the number of Americans over 65 with hearing loss could be as high as 40 percent.
"A lot of people have come to accept hearing loss as a part of aging," says Dr. Bevan Yueh, the study's lead author. "What shouldn't be accepted is the resulting loss of quality of life. There's effective treatment available for hearing loss."
Yueh, a staff surgeon and research associate at the Veterans Affairs Puget Sound Health System in Seattle, says many cases of hearing loss among the elderly could be easily detected by a primary-care physician with one of two quick, simple screening methods.
A hand-held audioscope emits tones to test hearing and can also be used to examine the eardrum. And a short questionnaire can often reveal hearing difficulties.
Less than 10 percent of primary-care physicians, however, screen elderly patients for hearing loss, the study says, and only 25 percent of patients who could benefit from hearing aids receive them.
"It's kind of sad to think that there's a major disorder out there and that it's under-treated and under-recognized," says Yueh, who also is an associate professor at the University of Washington's medical school and school of public health.
He noted that primary-care physicians routinely do eye exams and blood pressure tests, and they could easily perform hearing tests as well. The audioscope test, for example, takes just one or two minutes, less time than a blood-pressure exam, and a patient could easily complete the hearing questionnaire in the waiting room.
The researchers found strong links between hearing loss in the elderly and social isolation, depression, low self-esteem and difficulty functioning. Depression, for instance, is twice as prevalent in the hearing-impaired, Yueh says.
"A lot of people with even mild to moderate hearing loss are socially isolated, stay home and turn up the TV and don't realize how bad it is," Yueh says. "Some of them who come didn't talk to the grandkids anymore, didn't have any social life. Then they got the hearing aids, and now they live life fully again."
Screening is vitally important because often the patients themselves fail to realize they have hearing loss, Yueh says. Gradual hearing loss, he says, is often imperceptible even to the sufferer and requires tests to detect.
"The classic thing is for a patient to come in and say, 'You know, I don't have a problem, but my wife told me to come in because she thinks I have a problem,'" Yueh says. "The patients are not even acknowledging the possibility because it happens so gradually, they think, 'How could I have hearing loss?'"
More than 90 percent of hearing loss is sensorineural, or nerve deafness, which typically results from damage to the hair cells of the cochlea, and nerve deafness due to aging is the most common form of hearing loss in the United States, the study says.
Nerve deafness is characterized by the loss of ability to hear high-frequency sounds and difficulty filtering out background noise. There is no treatment, but hearing aids can greatly improve hearing and, in severe cases of hearing loss, a cochlear implant, an electronic device implanted behind the ear, can bypass the hair cells to stimulate auditory nerve fibers directly.
Unlike nerve deafness, conductive hearing loss results from abnormalities of the middle and external ear and generally requires surgery, the study says.
Hearing loss is the third most prevalent among condition among elderly Americans, behind high blood pressure and arthritis. And as baby boomers age, the number of seniors with hearing loss is expected to grow markedly. By 2030, some 21 million Americans age 65 and older are expected to have hearing loss, the American Speech-Language-Hearing Association predicts.
Dan Denston, administrative director of the Better Hearing Institute, says the study underscores the need for routine screening for hearing loss among the elderly.
The institute has launched a national campaign to try to impress upon primary-care physicians the importance of screening for hearing loss.
"They have an eye chart on the wall, but a primary-care physician very seldom asks patients about their hearing, " Denston says. "So what we're trying to do is educate that physician to say to the patient, 'OK, what about your hearing?' and to test hearing and refer the patient to a specialist, if necessary."
To learn more about hearing loss in the elderly, visit the National Institute on Deafness and Other Communication Disorders. Think you might have a hearing problem? Take this test from the American Speech-Language-Hearing Association.