Cochlear implants are electronic devices that try to do the same work that a normally functioning cochlea does to transmit sound. While the cochlea uses hair cells, cochlear implants electrically stimulate the auditory nerve. This is done to "produce a sensation of sound."

This is very different than the work of a hearing aid, which simply makes sound louder and passes it through the cochlea. The implant changes the biology of hearing, ignoring the cochlea and directly stimulating the auditory nerve.

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Cochlear implants have two parts: one internal and one external. The internal part is a receiver that is surgically implanted in the ear through an operation. The external part includes a speech processor, behind the ear microphone, and a transmitter. This is usually connected 4-6 weeks after the surgery. Both devices need to be fitted properly before it can be used.

The implants can be either inside (multi-channel) or outside (single-channel) of the cochlea.

Cochlear implants can benefit people who have severe or profound hearing loss and have normally functioning auditory nerves. For the best results, the implant should be given shortly after the hearing loss began. (The longer you wait, the more likely that the auditory nerves will not function properly.)

Using a cochlear implant does not suddenly make a person hearing. It normally requires a lot of training, patience, and rehabilitation. The National Association for the Deaf (America) notes that this usually means post-implant therapy sessions and regular meetings with audiologists and speech/language paathologists.

After going through this process, some people may be able to understand speech much better. For many people, though, sign language, speech-reading, and gestures are still needed for communication.

The Kenyan Society for Deaf children says cochlear implants are not available in Kenya at this time. They estimate that the operation alone may cost around Ksh 200,000/- ($2,850). Further expenses are needed for the rehabilitation, training, and maintenance that are required after the surgery.

Reference:

Brochure from Kenya Society for Deaf Children.

"Cochlear Implants," National Association for the Deaf. Accessed on January 9, 2007.