Implants sounding better

May 2, 2000

By Anita Manning, USA TODAY

A generation ago, restoring hearing in people who were profoundly deaf seemed unrealistic, if not impossible . Today, a growing fraction of the half-million Americans who suffer severe hearing loss are using cochlear implants, a sophisticated and controversial technology that many think is nothing short of a miracle.

A cochlear implant is more than a fancy hearing aid.

It is "one of the 20th century's most consequential developments in communication," John Niparko, director of otology-neurotology at Johns Hopkins Hospital in Baltimore, writes in the book Cochlear Implants: Principles & Practices.

Cochlear implants pick up sound through a tiny microphone attached near the ear. The implants send the sounds through a processor and back to a transmitter that delivers the sounds through electrodes, which stimulate the auditory nerve.

Scientists are working on producing smaller units that process signals faster, enhanced processing to improve the perception of speech and music, and fully implantable devices, which are expected in three to five years. First marketed in 1972, the implants are used by about 32,000 people worldwide, and the demand for them is growing by 25% per year, manufacturers say.

The most common hearing loss (85%) is caused by damage to tiny cochlear hair cells in the inner ear, called sensorineural hearing loss or "nerve deafness." The damage can be genetic or caused by a disease (such as meningitis or measles), injury, aging or a reaction to drugs, including some antibiotics and anti-cancer medications.

The devices cost $30,000 to $50,000 and are prescribed only to people whose hearing loss is severe and who do not benefit from hearing aids. Unlike hearing aids, implants are covered, at least in part, by most insurance companies.

Their use in children has been controversial, and their success somewhat spotty. Generally, Niparko says, the younger the child is when implanted, the easier it is for him or her to learn to understand sounds and to speak.

Research shows that exposure to speech early in life is crucial to language development. If the brain has no knowledge of sound, it can't immediately interpret sound information accurately.

"We have to work with Mother Nature in providing this at the optimal time," Niparko says. "Three (years of age) is not too old, but 5 may be. Three may not be as good as 18 months, and 18 months may not be as good as 12 months."

That doesn't mean children who are older are never successful with implants. "We do tell parents an implant experience can be wonderful, but it is a hell of a lot of work," he says. "Getting a child of 3, 4, 5 on schedule with language development is difficult."

But for babies 18 months old and younger, Niparko says, an implant is "a simple developmental experience." When a child is born deaf and doesn't get an implant for years, there is a language gap, he says. "It's easier to backfill that gap if a child is younger."

For adults who lose their hearing, implants can be what David Rutledge, 53, of Lincoln, Neb., calls "truly a miracle of modern science."

Rutledge, an elementary school principal, lost the hearing in one ear 10 years ago as a result of a never-identified flulike illness. His other ear was affected, but he got by. Then, in October, after another bout of flu, he lost all ability to hear.

In February, he got a cochlear implant, but he had to wait until he had completely healed from the surgery before his doctor turned it on.

In the interim, "I was totally and completely deaf," he says. "It was like living in a silent cave." He took a leave of absence from work. Unable to read lips and not knowing sign language, he and his family were reduced to passing written notes.

When the implant was turned on, what he first heard "was a pinball game of sound," he says, speaking by phone two weeks after the big event. "Imagine standing in a casino where everybody is winning. That's what it sounded like for the first 10 seconds. I could see my doctor's lips moving, but there was no relation between that and the pinball sound.

"But in 10 seconds my brain was able to take those sounds and make them into sound I could understand. It still had that pinball quality around the edges of the words, but within two minutes I could converse with everyone in the room and banter with them. Now, it's still not perfect, but it's becoming increasingly perfect."