March 24, 2005 -- Most deaf kids learn to hear after getting cochlearimplants. And they keep on hearing, a long-term study shows.

A cochlear implant isn't a hearing aid which amplifies sound. Part of thecomputerized device is implanted under the skin behind the ear -- withelectrodes that go deep into the ear. The devices turn sound waves intoelectric signals that are passed to nerve fibers leading into the brain. Theyallow even profoundly deaf people to hear.

It's not an overnight cure. People have to learn how to make sense of thesignals a cochlear implant gives to the brain. At first it sounds like amechanical noise. But eventually the brain adapts and recognizes more normalspeech sensations. This takes time and lots of work. And it's not cheap. Theaverage cost, including surgery and rehabilitation, is $40,000.

Over the long haul, is it worth it? For kids the answer is yes, suggest JanHaensel, MD, and colleagues at Germany's Aachen University Hospital. Theresearchers collected data on 16 kids who got cochlear implants 10 to 13 yearsago. They report their findings in the March issue ofOtolaryngology.

Best Results in Youngest Kids

Overall, Haensel's team found that 14 of 16 kids who got implants now saythey can hear. Four of the kids learned to hear and speak well enough to entermainstream schools. But six of the kids never learned to understand normalspeech.

The kids in the German study were 3 to 12 years old when they got theirimplants. Those who never learned to understand normal speech got theirimplants latest. That's because there's a window of opportunity for children toget the maximum benefit from cochlear implants, says Douglas Mattox, MD,professor and chair of otolaryngology at Atlanta's Emory University.

"There is a window that closes after which the implant is of novalue," Mattox tells WebMD. "That is sometime in childhood. Whether itis age 4 or 6 or 8 years we don't know, but clearly [getting implants] earlieris better."

Haensel's team says that their results led them to refuse to do implants onkids over the age of 6 years. That's anathema to Jane R. Madell, PhD, whobristles at the idea. Madell is co-director of The Beth Israel/New York Eye& Ear Cochlear Implant Center, and director of the hearing, speech,language, learning center at Beth Israel Medical in New York.

"I guarantee kids implanted at 6 or 8 or 10 won't do as well as thoseimplanted at 10 months," Madell tells WebMD. "But they still will getoutstanding benefit. That is not a reason not to do implants in olderkids."

Mattox, too, says that doctors currently get better results than thosereported by Haensel's team.

"This report understates, not overstates, the expected results ofcochlear implants in children," he says. "In Atlanta, childrenimplanted before age 3 are mainstreamed in school before they reach the middleyears of primary school."