They said yesterday they now have proof that the treatment works for children. "It is essential to treat before the age of five," Gerard O'Donoghue, one of the surgeons who heads the Nottingham team, said.
Every year 220 children are born deaf and another 80, most of them about one year old, become deaf following meningitis. In addition to a backlog of 1,200 suitable children, he said that 300 children a year would be candidates.
Unlike adults who become deaf and whose speech is already established, deaf babies and young children need to learn the meaning of sounds quickly if they are to establish speech.
After an implant has been fitted the learning process begins slowly, but children quickly improve after about two to three years, Sue Archibold, the team co-ordinator, said. "To start with they will sound like the babbling of a six-month-old baby. But remember how long it takes for a baby to acquire language."
At a briefing in London yesterday, results on 36 children aged two to eleven with cochlear implants were published. The study is part of a larger survey for the Department of Health.
Children up to the age of five do best, with most able to hear environmental sounds and speech. After the implants have been in place for five years, most will have spoken language, will understand simple conversation without lip-reading and be able to talk intelligibly to people not experienced in communicating with deaf children. Many will also be able to use the telephone.
A conventional deaf aid amplifies sounds, but cochlear implants work by directly stimulating the nerve tissue of the inner ear. Patients then have to learn to interpret the sounds which the brain hears.
The treatment is controversial. Not all health authorities are prepared to fund the treatment, believing it to be experimental or too expensive, and some members of the deaf community believe children should be old enough to make an informed choice before it is undertaken.
The treatment costs £30,000 for the surgery and three-year training programme and £2,000 a year thereafter. Lord Ashley of Stoke, who became deaf when he was 45 and has had an implant fitted, said: "For me it has been a glorious transformation. I had memory and I maintained my grip on language. For a child with no knowledge of language it is a mountain to climb. The cost here is peanuts in terms of what this does for children. People without the problem do not understand how profound is the effect of loss of hearing. The money is nothing in comparison."
Tricia Kemp had to pay for her son Alex, who was born deaf, to be treated in Germany four years ago.
He is now six and able to take part in some classes for hearing children at his school. "He can now enjoy games, but his greatest pleasure is a music box which I tearfully put away when he was six months old, knowing he would never hear it. He listens every night and can hum along to the tune," she said.Reuse content