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 the device is and electronically stimulates the nerve of hearing. Part of 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

…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

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 best fit 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

Dummies” “Mapping for

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 loss – the hearing remaining in a person who has a hearing Speech Reading – speech recognition using auditory and visual cues