February 2, 2006
Hearing-Loss Growth Speaks Volumes
Catherine Strick didn't know she was losing her hearing until five years ago when she went for her first annual physical and took a routine hearing test. Now, the 44-year-old accountant readily admits she has trouble hearing, and says people are quick to notice.
"My husband gets frustrated," she said. "The people I work with are always repeating themselves. My cellphone is on maximum volume so people can almost hear my conversations."
There are many reasons why people experience hearing loss -- congenital ear deformities, tumors, chronic diseases, side effects of some medications, viral infections of the inner ear, and blunt trauma. However, the majority of hearing loss cases can be attributed to the simple act of growing old. As the population ages, the National Institutes of Health says hearing impairment is a growing public health concern. Nearly 28 million Americans alone currently have trouble hearing, according to the NIH, and that number is expected to double by 2030.
In addition to age, noise is also to blame. Baby boomers are experiencing hearing loss earlier than previous generations as a result of too much time spent listening to loud music, living in noisy, urban environments, and working in fields like construction or welding.
"Every time people are exposed to loud noises for sustained periods of time, they are at risk of losing hair cells in the inner ear or cochlear," said Dr. Hamid R. Djalilian, an assistant professor of surgery at UCLA. "Stereos and personal music devices turned to a loud level can cause damage to hearing over time. Once people get to the age of 50 and 60, when the age-related hearing loss starts, they have already lost many hair cells and the cumulative effect starts affecting them more severely."
The normal ear contains about 15,000 hair cells, said Dr. John House, president of the House Ear Institute, a nonprofit research and education organization in Los Angeles. The hair cells are nerve endings that, like the pianos on a keyboard, control the high and low frequencies of sound.
"These nerve endings convert vibration to an electrical impulse which travels to the brain where it is interpreted as sound," he said.
Hearing loss often takes up to 10 years to be detected because damage to the hair cells occurs over time.
"As we age, we lose hair cells, especially in the higher frequency range, and it's those higher frequencies that help us distinguish words," said Dr. Andrea Vambutas, medical director of the Apelian Cochlear Implant Center at the North Shore-Long Island Jewish Health System in Manhasset, N.Y.
Progress to combat the effects of hearing loss is being explored on many fronts. "At the House Ear Institute, we are doing research into hair cell regeneration," House said. "Some day we'd like to be able to regrow those little hair cells and reverse hearing loss."
Although research has shown that hair cells can be regenerated in deaf animals, Djalilian says it will be years before tests are done on humans.
Cochlear implants, are surgically implanted devices that include a headpiece, speech processor, receiver and an implanted stimulator. They are generally used in people with severe to profound hearing loss in both ears. The implants take over all the work of transmitting external sound to the brain. In the next five years, newer models are expected to restore hearing in frequencies that conventional hearing aids do not help, meaning more people will benefit.
An auditory brainstem implant that bypasses the ear and hearing or auditory nerves altogether, and is implanted directly on the brainstem, is offering hope to patients who are deaf as a result of tumors in both auditory nerves. It includes an external microphone and battery pack, but Vambutas says hearing different sounds at high or low frequencies is still difficult.
People who experience the most common age- or noise-related hearing loss can benefit now from the significant advances that have been made with digital hearing aids. They are smaller, and more powerful, audiologist Barbara Olsen said, and can be programmed to suit an individual's hearing loss. They reduce background noise interference, which was common among older analog models, and cancel out annoying feedback. Newer ones can also adjust automatically to the environment the wearer is in, whether it's a noisy office or a quiet living room.
"It makes it more palatable for people," she said.
Despite the newer technology, only 25 percent of people who need hearing aids actually wear them.
Jean McCarthy of Sayville, N.Y., was hesitant to wear a hearing aid until three years ago because her mother had such a difficult time with the old, larger analog type.
"I went through so much with my mom. If she walked in a room with four or five people in it, she could hardly stand it. Everything was magnified. Every noise sounded 10 times louder than it was. I really didn't want to deal with it."
In fact, McCarthy didn't seek help until her children convinced her to. Now, that she wears a digital hearing aid, the 74-year-old retired school nurse said, "I'm amazed at how wonderful it is."
Vanity is another reason people won't wear hearing aids.
"Most people don't like wearing hearing aids because they don't want to appear old or deaf," Djalilian said. The cost of hearing aids can also be prohibitive. Most are not covered by insurance, and can run anywhere from $400 to $3,000 per ear depending upon the hearing aid.
Unfortunately, avoiding treatment can impact not only the individual, but also their loved ones, said Richard Carmen, an audiologist and author of "How Hearing Loss Impacts Relationships" (Auricle Ink Publishers). Relationships become strained when there is constant miscommunication and self-denial of a condition that is easily treated. "It leads to a tremendous amount of frustration. That wears down family relationships very quickly."
Rosemary Briggs of Massapequa Park, N.Y., got her hearing aids after "my husband said you've got to do something. It's getting everyone upset that you're not hearing."
Now, nearly 20 years later, she says her children still get frustrated with her: "My children should be more patient."
Strick, who is one of Briggs' daughters, agrees. "I should realize that I know what it's like for me, but I don't," she said.
And despite her own awareness, Strick says she still isn't ready to wear a hearing aid herself.
"It's like wearing glasses. When you start wearing them, you say this is amazing. But then you become so dependent on the glasses that you can't function. Say I wear a hearing aid and I can't hear without it. What happens when I go to the beach or swimming in the pool? Will I not be able to wear them and then I won't be able to hear my kids? My feeling is, until it gets to the point where it's really bad, I won't do it."
Debbe Geiger is a freelance writer specializing in health and science.