Georgia State University Series

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Georgia State University Series

• Cochlear Implants
• Part 2, Presentation 1
• July 2001

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Cochlear Implants

• Dr. Easterbrooks

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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.

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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
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Cochlear Implant History

• Pre-1960s
• - beginning studies of electrical stimulation
  on humans
• 1960s
• - active research of electrical stimulation in
  human ears
• 1970s
• - first wearable implants designed for
  long-term stimulation
• 1980s
• - commercial development of the cochlear
  implant device began

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continued

• 1985
• - 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

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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.

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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

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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

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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

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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.

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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

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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

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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
  best-fit hearing aid.

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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

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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

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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.

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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

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Mapping

• Programming
• Stimulating
• Choosing frequencies
• Speech Coding

http//www.listen-up.org Mapping for Dummies
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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.

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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.

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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.

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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

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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.

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• The CHOICE
  is YOURS

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Resources

• http//216.133.14.145/gettingstarted/history.htm
• http//text.nlm.nih.gov
• http//depts.washington.edu/otoweb/cochlear_implan
  ts.html
• http//www.listen-up.org
• http//www.rnid.org.uk/html/info_factsheets.htm
• http//deafness.about.com/health/deafness/gi/dynam
  ic
• http//www.entnet.org/cochlear-implant.html
• http//www.pbs.org.wnet/soundandfury/cochlear/deba
  te.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

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Glossary

• Auditory Training instruction designed to
  maximize an individuals 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