Hesperian Health Guides
Appendix B: Cochlear implants and hearing
People are able to hear sounds because a part of the inner ear called the “cochlea” sends signals about sound to the brain. If a person’s cochlea is damaged or did not develop in the usual way, he will not be able to hear well. Even hearing aids may not be much help to this person.
cochlea
The cochlea is a small part of the ear inside the head. It is shaped like a snail's shell.
A cochlear implant is a small piece of equipment that can help some deaf people, including some people with damaged cochleas, hear sounds and understand speech. Though they are very expensive, cochlear implants are now available in many countries.
Parts of a cochlear implant
Part of the cochlear implant is worn outside the head like a hearing aid. And like a hearing aid, this part has a microphone that picks up sound from a person’s environment.
Other parts of the cochlear implant are inside the head. These parts receive sound information, change it to electrical signals, and send those signals to the brain. These parts of the cochlear implant are placed during an operation.
parts of the cochlear implant outside the head
parts inside the head