Sitting in an audiology clinic near Riverside Community Hospital, Ione Farmer, 90, tried on a state-of-the-art digital hearing aid for size.

The Riverside woman had been experiencing feedback from her own hearing aids, one in each ear. The whistling was hard to tune out without lowering the volume so much she couldn't hear.

"This has been a real challenge because of her degree of hearing loss," said audiologist Floyd E. Milner. "But this device has anti-feedback circuitry."

Cracking a smile, Farmer seemed pleased by what she heard - or didn't hear.

"I can't even tell it's in ...there's no squealing," she said about the device which features the latest open-fitting design.

Worn behind the ear, the aid was barely visible when covered by hair, with just a clear thin tube running into the ear canal. It's much more comfortable than her current aids.

Nancy A. Muller, 59, of Winchester, benefits from a more extreme technological innovation: a bone conduction implant performed last year at Loma Linda University Medical Center to treat deafness in her left ear.

The implant works by transferring sound via microphones from her deaf side through her skull bone to her good ear. The device consists of a titanium implant, an external connecting post and a detachable sound processor.

"It's just like stereo. It's incredible," she said. "I hook it onto the screw, turn it on and I'm in business. It picks up everything on the left."

Common Condition of Aging

About 28 million Americans like Farmer and Muller suffer from hearing loss. One-third of adults older than age 60 and up to half age 75 or older are hard of hearing, according to Dr. John W. House, president of the House Ear Institute in Los Angeles.

What's more, hearing loss is the nation's most common birth defect. One in every 1,000 babies is born profoundly deaf, while two or three in 1,000 newborns has partial hearing loss.

Normally the visible outer ear collects and directs sound waves from the environment via an external canal to the middle ear. There the eardrum and three tiny bones called ossicles amplify vibrations, which ripple through fluid in the spiral inner ear, or cochlea.

This sets off an electrical response in tiny sensory hair cells. The signal travels from the hearing nerve to the brain, which interprets it as sound.

Much, however, can go wrong along the way. For example, the cochlea's hair cells may break or bend -- or the cells themselves may degenerate, a condition called sensorineural hearing loss, or nerve deafness, said House.

"About 90 percent of age-related hearing loss -- called presbycusis -- stems from nerve damage," House said.

Causes include injuries, illness, heredity, natural aging or ototoxic drugs used to treat life-threatening illnesses, and even overuse of common acetaminophen or Vicodin, he said.

Regular exposure to loud noises such as gas-powered gardening equipment, firearms, motorcycles and loud music can damage hearing.

Affecting about 10 percent of patients, conductive hearing loss stems from an interruption in the path sound travels through the middle ear, said House. Causes can be wax or fluid buildup, a perforated eardrum or bone abnormalities. Some people, moreover, have a combination of conditions.

Hearing loss can occur suddenly or progress slowly . It can affect both ears or just one.

Muller lost hearing in her left ear more than 20 years ago from an injury to her auditory nerve -- a complication of surgery to correct chronic dizziness.

"I was free of vertigo but I lost half my hearing," Muller said. "It was chancy surgery and an OK tradeoff. But it changed my lifestyle a lot."

She wore various hearing aids, including a device with a microphone on her left ear that transmitted sound to the good right ear. "But it sounded tinny and distorted," she said. "Eventually I totally gave up on hearing aids until I had the bone conduction implant."

Available in the United States since 1996 for conductive and mixed hearing loss, the procedure was approved in 2002 by the U.S. Food and Drug Administration for single-sided deafness, which affects an estimated 60,000 Americans each year.

Often the first sign of trouble is a perception everyone around you is mumbling or complaints from family members that the TV is blaring.

In addition to difficulty making out high-pitched tones or spoken words against background noise, other symptoms may include a hissing, ringing or buzzing in the ears -- a condition called tinnitus.

Many people avoid getting their hearing tested out of embarrassment. But a basic ear exam may reveal easily treatable conditions such as wax buildup or fluid in the middle ear.

Sophisticated Options

As Farmer learned, the latest hearing aids are significantly better and more flattering cosmetically than those even a decade ago.

"The open-ear designs that just came on the market are exciting breakthroughs," House said "These allow 'multiple listening situations,' or programs pre-set by an audiologist," he said. Users can switch from program to program to accommodate a noisy restaurant or quiet music.

Other assistive listening devices use infrared to broadcast amplified signals. These include phones, alerting systems for smoke detectors, doorbells and alarm clocks.

If impairment is too severe for a hearing aid, a patient may qualify for a cochlear implant.

Developed at the House Ear Institute, the cochlear implant is an electronic device that bypasses damaged hair cells and stimulates the hearing nerve directly. It provides useful hearing and improved communication abilities.

"Some do really well and others not so well depending on the cause and other factors," House said. "But about 80 percent of cochlear implant patients can today talk on the phone."

According to House, the procedure is a safe, reliable and effective treatment for severe-to-profound hearing loss in adults and profound hearing loss in children.

Muller recalled that before her bone conduction implant it was hard to tell what direction sounds came from, even at home.

"Now I can hear without having to keep twisting my neck around," she said.

By Mike Schwartz
http://www.pe.com/lifestyles/healthandfitness/stories/PE_Fea_Daily_S_hearing0627.10526fc.html