The Deaf Get Wired for Sound

0 Comments | Insight on the News, Oct 18, 1999 | by Susan Boswell

Cochlear implants -- devices that help the dealer hear -- are safer and more sophisticated. Doctors are recommending them for ever-younger patients.

Four months after Joey Gluchowski was born, he lost his hearing to meningitis. Before he was a year old, he became one of the youngest people in the United States to receive a cochlear implant.

Today, after using the implant for six months, Joey's hearing and speech abilities are improving, according to Patricia Chute, director of the Cochlear Implant Center at Lenox Hill Hospital in New York City. "Joey responds to his name being called in another room, to his siblings and a variety of toys," says Chute. "He'll even pick up the phone and say `hi'."

Joey is one of more than 25,000 individuals around the world who have benefited from cochlear implants that bring sound from silence. Doctors are Wearing hearing loss in some patients by surgically implanting an array of electrodes in their inner ears, bypassing damaged cochlear hair cells to stimulate the auditory nerve directly.

The device combines old and new technologies. Outside the ear, an implanted microphone and speech processor -- a powerful miniaturized computer -- receives, filters, analyzes and digitizes sound into coded signals. The processor forwards the signals inside the ear through coils and an electrode array that winds around the snail-shaped cochlea in the inner ear, electrically stimulating surviving nerve fibers. The implant can process sound in microseconds, so recipients hear noise as it occurs.

The Food and Drug Administration, or FDA, approved cochlear-implant devices for adults in 1985 and for children in 1990, but only those with no measurable effectiveness from hearing aids qualified. Candidacy for implants steadily has expanded during the nineties. "Cochlear implants have been proven to be safe and effective," says Renee Levinson, an audiologist at the American-Speech-Language-Hearing Association. "There have been technological improvements, and audiologists have greater familiarity and expertise in working with these devices."

The FDA has approved cochlear implants for toddlers as young as 18 months as well as children who have some residual hearing -- who can recognize up to 20 percent of words spoken without speechreading. Even infants like Joey have received implants if they have had meningitis or show evidence of ossification, or bony growth, within the cochlea.

"For infants with severe to profound hearing loss, you have to teach them to understand the meaning of sound and then compare whether they function as well as a child with a cochlear implant," says Margo Skinner, director of the cochlear-implant program at the Washington University School of Medicine in St. Louis. "If they cannot function as well as children with implants, they are candidates."

Implants can deliver sound uniformly across the entire auditory spectrum, including soft levels, particularly important in the development of speech and language. "Often when kids get an implant, the first change is the ability to pick up the `s,'" says Skinner. "They hear these soft, high-frequency speech sounds -- and it's so evident. After several years of implant use and educational training, the average child can understand approximately 30 to 40 percent of one-syllable words without relying on speechreading."

Researchers at Johns Hopkins University School of Medicine in Baltimore say that children with implants are mainstreamed faster, at younger ages and at higher rates than children without implants. They are more likely to attend their neighborhood school and use fewer academic support services, saving up to $100,000 per child in special-education costs.

"Children's friendships are richer because people can talk about the trivia of life without always having to repair communication breakdowns," says Skinner. "Cochlear implants also help build self-esteem and communication competency. If a child can't communicate easily, sometimes people give up trying and the child is left feeling like he's failed."

Though new technology has made implants practical, rehabilitation remains the key to success, say audiologists. Adults who receive cochlear implants typically have a lifetime of auditory memories to draw upon, but children born with profound hearing loss have no understanding of sound. "A brain that has never heard will not recognize anything that comes in," says Mary Koch of the Listening Center at Johns Hopkins. "Rehabilitation creates the auditory `roadways' to channel the information coming through the implant."

The center's 12-month rehabilitation program takes children through a step-by-step process of language acquisition similar to that of hearing children: learning to attach meaning first to syllables, then to words, phrases and sentences. Weekly auditory rehabilitation sessions sometimes are videotaped for the rest of the family to watch. "My role was to help her family weave listening into everything they did throughout the day," Koch says of Cecilia Grugan, just 3-and-a-half years old when she received her implant.