A cochlear implant is a small electronic device surgically implanted under the skin behind the ear. It converts sound to electrical impulses and sends them to the brain. In this way, it can help people with severe or profound hearing loss who wouldn't benefit from a hearing aid.

"The notion has been that you want to implant the ear that is more alive, if you will -- the ear that has heard most recently and has had more hearing experience," says Dr. Howard Francis, a researcher at Johns Hopkins University in Baltimore. But using an implant in an ear with residual hearing makes that ear unavailable for use with a hearing aid.

"So why not put it in the ear that is deaf, and leave the one with residual hearing available for a hearing aid?" Francis says.

He and his colleagues decided to see whether this strategy would be just as effective as the traditional approach.

They studied 43 adults who were profoundly deaf in one year and had severe hearing loss in the other. Thirty-six had cochlear implants in their profoundly deaf ear, and they did just as well as patients who had the implants in their better-hearing ear. They also showed improvements in their ability to understand speech in a noisy environment.

In people who have been able to use their residual hearing ability via hearing aids, the brain appears to be able to use the artificial stimulation of a cochlear implant more effectively, Francis says.

From The Medical Post