A cochlear implant is a technological device intended to enhance
the hearing of persons who are deaf. There are more than 70,000
people (as of fall 2005) with cochlear implants worldwide—and
about half are children. Experience and research suggest that
a cochlear implant can bring a greater awareness to a broader
range of sounds for many deaf children in comparison to traditional
hearing aids. Use of this device requires participation in an
often rigorous pre-implantation protocol to determine candidacy,
surgery to implant a portion of the
device, an activation process to program an externally worn portion
of the device, and participation in an intensive training program,
as well as an appropriate educational program
to actualize benefit from the device.
There are three manufacturers of cochlear implants commonly used
in the United States. Each of these manufacturers provides extensive
(promotional) resources at no charge about their specific brand
of cochlear implant, as well as general information about implants.
(See the contact information for each of the manufacturers in the
Resources section.)
- Advanced Bionics
Corporation is the manufacturer of the body-worn Platinum
Sound Processor and HiRes AURIA behind-the-ear device.
Older generation devices include the CII BTE™ and
Platinum BTE.™
- Cochlear Corporation is
the manufacturer of the Nucleus® Freedom™ body-worn
and ear-level devices. Older generations of the device include
the Spectra and Sprint body-worn processors and the Esprit
and 3G BTE processors.
- MED-EL Corporation is
the manufacturer of the TEMPO+ speech processor which provides
a total of five wearing options. It has a modular design and
four available battery packs.
Components of the Device
A cochlear implant is comprised of surgically implanted and externally
worn components. The surgically implanted components include:
- a receiver/stimulator housed in a bio-compatible case,
which is surgically implanted under the skin behind the ear, and
contains a magnet, which couples to the magnet in the transmitter
worn externally; and
- an electrode array inserted into the cochlea to provide
direct electrical stimulation to remaining nerve fibers.
The externally worn, non-implanted components of the device include:
- a microphone similar to the microphone of a hearing aid,
- a speech processor that can be worn on the body (pager
style, connected to the headpiece by a cable) or behind the ear
(similar to a hearing aid), and
- a transmitting coil, a small disk about the size of a
quarter, which adheres to the skin behind the ear via a magnet
and is connected to the microphone by a small cable.
How a Cochlear Implant Works
| Sound picked
up by microphone |
 |
Sound sent
to speech processor |
|
Speech processor
filters, analyzes, and digitizes sound into coded electrical
signals |
|
Coded signals sent from speech processor to transmitting coil
via cable
|
|
Transmitting
coil sends signals across skin to internal implanted receiver/stimulator
via an FM radio signal |
|
Receiver/stimulator
delivers electrical stimulation to appropriate implanted electrodes |
|
Electrodes
stimulated and sound carried to brain via auditory nerve (eighth
nerve) |
For more information about how a cochlear implant works, see:
MED-EL:
How a Cochlear Implant Works
Advanced Bionics: How
Implants Work and Bionic
Ear Informational Videos
Cochlear
Americas: How Cochlear Implants Work
For More Information
While it is unknown how any one person perceives sound through
a cochlear implant, the following Web site provides sound simulations
that approximate this experience:
http://www.utdallas.edu/~loizou/cimplants/tutorial/
Fact Sheets describing the basic components of a cochlear implant
can be found at the following Web sites:
The
Alexander Graham Bell Association for the Deaf and Hard of Hearing
(AG Bell)
AG
Bell: Kids and Cochlear Implants: Getting Connected (PDF)
The
American Speech-Language-Hearing Association (ASHA)
The Cochlear Implant
Association, Inc. (CIAI)
Educational Resources
Information Center (ERIC): Educating Children Who Are Deaf or Hard
of Hearing: Cochlear Implants
The
National Institute on Deafness and Other Communication Disorders
(NIDCD)
U.S. Food and Drug
Administration: Cochlear Implants
Revised June 2006
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