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Georgia State University
Series
Cochlear Implants
Part 2, Presentation 1
July 2001
Cochlear Implants
Dr. Easterbrooks
What is a Cochlear Implant?
The cochlear implant (CI) is a
prosthetic replacement for the
inner ear (cochlea) and is only
appropriate for people who
receive minimal or no benefit
from a conventional hearing
aid.
…continued
The cochlear
implant bypasses
damaged parts of
the inner ear and
electronically
stimulates the nerve
of hearing. Part of
the device is
surgically implanted
in the skull behind
the ear and tiny
wires are inserted
into the cochlea.
http://www.listen-up.org
Cochlear Implant History
Pre-1960’s
- beginning studies of
electrical stimulation on
humans
1960’s
- active research of
electrical stimulation in
human ears
1970’s
- first wearable implants
designed for long-term
stimulation
1980’s
- commercial
development of the
cochlear implant device
began
1985
…continued
- United States Food &
Drug Administration
(FDA) granted the first
approval for implantation
in adults
1990
- FDA granted approval
for cochlear implants in
children
Today
- cochlear implantation is
a safe and effective
medical procedure for
individuals who are
severely to profoundly
deaf with minimal benefits
from conventional hearing
aids
http://216.133.14.145/gettingstarted/history.htm
Who is a Candidate?
Candidates for implants are
adults or children (two
years or older) with all of
the following:
Profound or severe hearing
loss in both ears (this includes
people with so-called "nerve"
deafness).
Hearing aids but receive little
or no benefit from them in
understanding speech by
listening alone.
…continued
No medical reason to
avoid surgery.
A desire to interact with
the hearing world and to
communicate with spoken
language.
Realistic expectations
about results.
http://text.nlm.nih.cdc/www/100txt.html
Four Basic Parts of a
Cochlear Implant
A microphone, which picks up
sound from the environment;
A speech processor, which
selects and arranges sounds
picked up by the microphone;
Continued…
A transmitter and receiver/ stimulator,
which receive signals from the speech
processor and convert them into electric
impulses;
And electrodes, which collect the impulses
from the stimulator and send them to the
brain.
www.nidcd.nih.gov/health/pubs_hb/coch.htm
How Does a CI Work?
 Sound is received by an
microphone that rests over the
ear like a behind-the-ear hearing
aid.
 Sound is sent from the
microphone to the signal
processor by a thin cable.
 Signal processor translates the
sound into electrical codes.
 Codes are sent by a thin cable
to the transmitter held to the
scalp by its attraction to a
magnet implanted beneath the
skin.
…continued
 Transmitter sends codes across
the skin to a receiver/stimulator
implanted in the mastoid bone.
 Receiver/stimulator converts the
codes to electrical signals.
 Electrical signals are sent to the
specified electrodes in the array
within the cochlea to stimulate
neurons.
 Neurons send messages along
the auditory nerve to the central
auditory system in the brain
where they are interpreted as
sound.
http://www.listen-up.org
Subject factors that might
affect the performance of
the CI:
Etiology
Age and Onset of Deafness
Age at Implantation
Residual Hearing
Functioning auditory nerve
For adults: Good speech,
language, and
communication skills
Good motivation
Support from family and
friends
http://text.nlm.nih.gov
What is involved in an
evaluation?
Ear examination to
determine cause of
hearing loss and
absence of infection.
Medical examination
for eligibility for
surgery and
anesthesia.
Hearing ability testing,
with and without bestfit hearing aid.
…continued
Evaluation of
communication skills.
CT scan to determine
patency of the inner
ear (cochlea).
In adults - balance
tests to determine the
risk of postoperative
dizziness.
http://depts.washington.edu/otoweb/
cochlear_implants.html
Surgery
Risks are the same for
any other ear surgery
Risks are considered
minimal
Procedure takes
approximately 1-2 hours
Hospital stay is usually
one day for adults and 1
to 2 days for children
http://depts.washington.edu/otoweb/
cochlear_implants.html
What is involved in a
CI follow-up?
For Adults:
* weekly adjustments of the
MAP and communication
therapy for the first month.
* treatment focuses on
auditory training, speech
reading, music, telephone use
& communication strategies.
…continued
For children:
* after the initial 3
month period, children
are usually seen every
3 months for the
first year and every 6
months for the second
and third years.
Thereafter, they
are seen annually.
* MAP is closely
monitored.
http://depts.washington.edu
Mapping
Programming
Stimulating
Choosing frequencies
Speech Coding
http://www.listen-up.org “Mapping for
Dummies”
Myths about Cochlear
Implants
People with Cochlear
Implants are only able to
distinguish environmental
noises, not comprehend
speech.
After someone gets a
Cochlear Implant, they're
immediately able to hear
normally and talk on the
phone.
Cochlear Implants fix or
cure deafness.
…continued
Cochlear Implants weaken the skull
so if someone with a Cochlear
Implant gets hit in the head, they
will fracture their skull.
The electrodes in a Cochlear
Implant go into the brain.
Cochlear Implant surgery is brain
surgery.
The cord for the Cochlear Implant
comes out of the neck.
People with Cochlear Implants are
unable to go swimming.
The Controversy
There are two camps with
very different opinions
about the Cochlear
Implant.
 There are those who see
the CI as a gift and a
miracle that will enhance
the quality of life for some
deaf and hard of hearing
individuals.
 There are those who see
the CI as a threat to Deaf
Culture and as a tool that
considers Deafness as a
disability.
Opinions in Favor of the CI
Gives accessibility to language
at the critical age for language
acquisition, assuming the oral
method is used.
The surgical procedure, while
invasive, is no more invasive
than routine operations such as
a tonsillectomy.
Gives access to a world of
education, social contacts, etc.
as a hearing child.
Possible avoidance of being
labeled, teased, isolated, etc.
as a “disabled” child.
Gives ability to be aware of
sounds.
Allows individuals to function
more “normally” in a hearing
world.
http://www.listen-up.org
Opinions Against the CI
The CI is ethically wrong. Being Deaf
is a birth right and not a disability.
A large portion of the Deaf Community
sees the CI as a threat to its very
identity.
The implant perpetuates the idea that
Deafness is a disability that should be
remediated.
Invasive surgery should be reserved
for life-threatening situations, not
simple life enhancements.
Offered the choice, many adults reject
the implant.
Decisions are made for children when
the long-term effects are still unknown.
The surgery makes a life-time
commitment for a child.
The
CHOICE
is
YOURS
Resources
http://216.133.14.145/gettingstarted/history.htm
http://text.nlm.nih.gov
http://depts.washington.edu/otoweb/cochlear_implants.html
http://www.listen-up.org
http://www.rnid.org.uk/html/info_factsheets.htm
http://deafness.about.com/health/deafness/gi/dynamic
http://www.entnet.org/cochlear-implant.html
http://www.pbs.org.wnet/soundandfury/cochlear/debate.htm
http://www.nidcd.nih.gov/health/pubs_hb/coch.htm
http://www.dww.deafworldweb.org/pub/c/ci.html
www.cochlear.com
www.cochlearimplant.com
www.hei.org/htm/cocimqu.htm
http://www.awesome-ears.com/contro.html
www.zak.co.il/deaf-info/old/ci-opinions.html
Glossary
Auditory Training – instruction designed to maximize an individual’s use of
residual hearing by means of both formal and informal listening practice
Etiology – physiological reason or cause for any anomaly
MAP – specifications of threshold, suprathreshold, and frequency by which
the speech processor of a cochlear implant processes the speech signal
and delivers it in electrical form to the electrodes in the electrode array
Residual Hearing – the hearing remaining in a person who has a hearing
loss
Speech Reading – speech recognition using auditory and visual cues