The findings may help explain why the implants are up to 80% successful in young children who have been unable to hear since birth. In contrast, the devices rarely restore hearing when implanted in congenitally deaf adults.

Cochlear implants are tiny devices designed to mimic the snail-like structure in the inner ear, which contains fluid-filled canals and tissues. It is here that sound vibrations are picked up by the ear drum and translated into electrical signals, which are transmitted through nerve fibres to the brain.

Cochlear implants are much more complicated than hearing aids, which merely amplify sound. The devices pick up sounds with an external microphone and transmit them as electrical signals to a receiver that is directly attached to the brain.

US scientists at the Johns Hopkins University Center for Hearing and Balance in Baltimore, Maryland, found evidence that in young children cochlear implants can reverse hearing loss. They do this by forging normal nerve connections that have failed to develop.

The procedure is only likely to work on young children whose brains and auditory systems are still developing.

The findings were reported in the journal Science.

Professor David Ryugo, who led the research, said: "What we think this study tells parents of deaf children is that, if cochlear implants are being considered, the earlier they're done the better.

"There is an optimal time window for implants, if they are to avoid permanent rewiring of hearing stations in the brain and the long-term effects on language learning that can result."

Source: http://www.dailymail.co.uk/pages/live/articles/health/thehealthnews.html?in_article_id=370324&in_page_id=1797