This page was created in partial fulfillment of BIO108, "Organ Replacement" at Brown University. Our objective is to provide a mechanistic understanding of how cochlear implants work, particularly with respect to how sound is decomposed into its components by the speech processor and transmitted to the auditory neruons by the electrode array.

Webpage Created by: Karthik Chivukula, Bryan Laulicht, Dorothy Marcello, Roshni Patel, and Robert Saphirstein

DISCLAIMER: The content of this page does not reflect the opinion of Brown University or any of its affiliates.

__________________________________________________________________

Candidacy

Costs, Risks, and Benefits

References

__________________________________________________________________

   
 

Candidacy

Prime candidates are patients with severe to profound sensorineural hearing impairments (damage to either the central processing center of the brain, the vestibulocochlear nerve or the inner ear) who retain some auditory nerve function (only hair cells are damaged). CI is most successful if the patient is young (i.e. several months to six years old), has lived a relatively short time without hearing and has a strong individual motivation and the support of family and friends with post-CI aural therapy. Generally, patients with mild to moderate sensorineural hearing loss or conductive hearing loss (soundwaves fail to conduct efficiently through either the outer ear, tympanic membrane ossicles) are not offered the cochlear implant (CI). Deaf patients with severe auditory nerve fiber damage are also not offered the CI, since a functioning auditory nerve is critical for transmitting signals from the CI to the brain.

Essentially there are two groups of patients for CI's: pre-lingual deaf children and post-lingual deaf adults. Younger patients who have been deaf for a relatively short period are preferred since with longer durations of deafness, there is an increased possibility that the brain will begin using its auditory center for other functions.

Back to top

__________________________________________________________________

 

Costs, Risks, and Benefits

The procedure costs between $15,000-$40,000. This covers not only the cost of the surgery and the device, but also of the requisite ensuing therapy. How much the hospital is reimbursed depends on the patient's coverage. In 2002, the Centers for Medicare and Medicaid Services agreed to reimburse hospitals $19,173 of the total cost. Though Medicare has a set amount of reimbursement, Medicaid can vary from state to state. Occasionally, families may have to resort to threatening legal action to receive coverage (see ASHA link). Fortunately, in the event that a potential CI recipient's insurance company denies her request, there are still other venues available. For example, the Let Them Hear Foundation is an insurance advocacy group that offers to cover the cost of CI surgery when the patient has been denied.

The procedure has several risks, including potential damage to the facial nerve during the surgery, possible infection at the site of implantation and tinnitus (ringing in the ears). In certain cases, Prozac is used to treat tinnitus.

The usual patient healing time is 4-6 weeks. Once the patient has healed, the external components of the CI are fit to the patients. During subsequent months, the patient undergoes "mapping," where the doctor makes adjustments to the speech processor.

Are the procedure, potential risks and grueling therapy worth it?

The CI allows deaf patients more freedom and comfort in various social settings. If they rigorously participate in their post-surgery therapy, CI recipients can greatly improve the efficacy of their implants. The results are especially dramatic in young pre-lingually deaf children. Prior to the CI surgery, deaf patients normally hear from 71 dB (for severe but not profound cases) to 91 dB and greater. Yet with the CI, and particularly with children, CI patients can hear sounds as soft as 15 dB.

It is important to emphasize that results may vary and are influenced by various factors, including how proactive and motivated the patient is. 95% of CI recipients continue to use the device a year after its implantation. For those patients in which the CI fails to improve their hearing, they discontinue use of the CI and learn to sign and lip read.

The CI requires relatively inexpensive and low maintenance. The batteries of the speech processor generally last between 16-24 hours. And for some CI patients, the batteries can last as long as five days. Furthermore, certain CI brands actually give a warning signal to the user, so that the patient has time to change the batteries. One patient reportedly spent $350 per year on replacing batteries, which the patient felt was " .a bargain considering what benefit I get from the cochlear implant ."

Back to top

__________________________________________________________________

References

Humphries, Tom L. and Padden, Carol A. Inside Deaf Culture. USA : Library of Congress of Cataloging-in-Publication, 2005.

"Candidates for Cochlear Implants." April 2006. http://www.hearinglosseducation.com/Implants/131.asp#

"Health Information: Cochlear Implants." April 2006 http://healthgate.partners.org/browsing/browseContent.asp?fileName=14793.xml&title=Cochlear%20Implants

"Cochlear Implant Presentation." April 2006. http://www.listen-up.org/ci/implant3.htm

"Hearing Loss and Deafness." April 2006. http://www.merck.com/mmhe/sec19/ch218/ch218a.html

"Hearing Impairment." April 2006. http://en.wikipedia.org/wiki/Hearing_impairment

"Family wins Cochlear Implant Insurance Victory." April 2006.

http://www.asha.org/about/publications/leader-online/archives/2005/051227/051227d.htm

Sorkin, Donna L. "Cochlear Implants and Insurance Reimbursement: Consumers and Industry Collaborate." April 2006. http://www.shhh.org/learn/sorkinjf03.asp

"Cochlear Implant." April 2006. http://en.wikipedia.org/wiki/Cochlear_implant

Malakoff, David. "Software May Improve Utility of Implants for Deaf."
http://www.npr.org/templates/story/story.php?storyId=4961269

Back to top