A cochlear implant is an electronic
device that improves hearing. It can be
an option for people who have severe
hearing loss from inner-ear damage who
are not able to hear well with hearing
aids.
Unlike hearing aids, which amplify
sound, a cochlear implant bypasses
damaged portions of the ear to deliver
sound signals to the hearing (auditory)
nerve.
Cochlear implants use a sound processor
that fits behind the ear. The processor
captures sound signals and sends them to
a receiver implanted under the skin
behind the ear. The receiver sends the
signals to electrodes implanted in the
snail-shaped inner ear (cochlea).
The signals stimulate the auditory
nerve, which then directs the signals to
the brain. The brain interprets those
signals as sounds, though these sounds
won't be just like natural hearing.
A cochlear implant uses a sound processor that's worn behind the ear. A transmitter sends sound signals to a receiver and stimulator implanted under the skin. They stimulate the auditory nerve with electrodes that have been threaded into the cochlea. Some types of cochlear implants have one outside unit that has a speech processor, microphone and transmitter combined (lower left). Others have these as separate outside parts (upper left and on right).