A cochlear implant is a small, complex
electronic device that can help to provide a
sense of sound to a person who is profoundly
deaf or severely hard-of-hearing. The
implant consists of an external portion that
sits behind the ear and a second portion
that is surgically placed under the skin
(see figure). An implant has the following
A microphone, which picks up sound from the
A speech processor, which selects and
arranges sounds picked up by the microphone
A transmitter and receiver/stimulator, which
receive signals from the speech processor
and convert them into electric impulses.
An electrode array, which is a group of
electrodes that collects the impulses from
the stimulator and sends them to different
regions of the auditory nerve
An implant does not restore normal hearing.
Instead, it can give a deaf person a useful
representation of sounds in the environment
and help him or her to understand speech.