Thank you to Ruth Fox for her assistance in preparing this page.
A Cochlear Implant is a technical device used to return some sound to those who have a severe to profound hearing loss. An implant is generally prescribed for persons with bilateral sensorineural hearing loss (a hearing loss in both ears resulting from nerve damage.) According to the University of Michigan cochlear implant program, cochlear implants differ in two major ways from hearing aids:
- “Hearing aids and other assistive listening devices simply amplify sounds. A cochlear implant, on the other hand, transforms speech and other sounds into electrical energy that is used to stimulate surviving auditory nerve fibers in the inner ear.
- Unlike most hearing aids, cochlear implants have both internal (inside the body) and external (worn outside the body) components. A surgical procedure is needed to place the internal processor component of the implant inside the head.”
Once the device is implanted and activated, the recipient receives auditory sensations that vary in pitch and loudness. The recipient must learn to interpret the sounds and develop oral/aural language skills.
Who is a prospective user?
Children who are 18 months to 17 years old with the following characteristics.
- Profound sensorineural hearing loss (nerve deafness) in both ears.
- Receive little or no useful benefit from hearing aids.
- No medical contraindications
- High motivation and appropriate expectations (both child and family)
- Placement in an educational program that emphasizes auditory skills after the implant has been fitted.
Adults who are 18 years or older
- Severe to profound sensorineural hearing loss (nerve deafness) in both ears
- Receive little or no useful benefit form hearing aids, i.e. a score of 40 percent or less on sentence recognition tests in the best–aided listening situation.
- High motivation and appropriate expectations
- No medical contraindications
- A desire to be a part of the hearing world
As with any medical procedure, evaluation by a qualified professional is essential. If you think you or your child might be a candidate for a cochlear implant ask your audiologist or physician for a referral.
How does it work?
The cochlear implant’s external microphone picks up sound, then converts it to electrical impulses for transmission to an electrical array implanted in the inner ear. The unit is designed to send the electrical impulses along leftover, undamaged residual nerve endings to the brain to interpret as sound. The idea is to mimic what the ear would do naturally, were it not for the damaged hair cells and nerve endings that are unable to convert sound to electrical signals for transmission to the brain.
- Awareness of environmental sounds
- Reduction in speech reading effort
- Reduction in communication stress/fatigue level
- Some understanding of speech without visual cues
- Potential ability to use telephone
- Some appreciation of music
A cochlear implant can make a profound impact in a recipient’s life. Consider these examples:
A child who receives an implant during the critical period of learning language
Infants and toddler are like language sponges. A child with normal hearing can learn multiple languages with ease. The brain, at this stage of development, is uniquely receptive to developing language comprehension. Later in life, most adults struggle to learn a second language. So, it is extremely important for young children to receive as much language exposure as possible. When language exposure is limited during this critical period (as may happen with children born deaf), speech and language development can be severely delayed or permanently impaired.
When infants and toddlers receive a cochlear implant, they begin to receive and decipher spoken language during this critical learning period. According to an article on the Cochlear Corporation website, one in five children who receive the device are able to learn spoken language and function in the “mainstream oral world.” Others are able to learn critical sounds for safety and well–being, such as dogs barking, horns, and loud machinery. Typically, the earlier a child receives an implant, the better the language comprehension outcomes. Children with severe to profound hearing loss, who use a cochlear implant for more than two years, are more than twice as likely as their peers to move into mainstream settings from special ed classrooms (Project HOPE, Policy Analysis Brief, April,2000).
Adult recipients who lost hearing after learning language
For people who grow up with relatively normal hearing, speech is usually the primary mode of communication. When a severe or profound hearing loss occurs, communication with friends and family becomes an arduous task. It takes great effort to understand a spoken language when it cannot be heard. In fact, only 30% of spoken language is visible, the rest must be guessed by a speech reader. When an adult loses their hearing, there is often a profound sense of isolation and loss. For these people the benefits of a cochlear implant cannot be overstated.
When an adult receives a cochlear implant, there may be a sense of rejoining the world. Where once there was isolation, now there is conversation. Where once there was silence, now there is music and children laughing. Communication barriers melt away and the person is again an active member of family and community. A draft report by the American Speech–Language and Hearing Association states that some recipients are able to understand 80% of words by hearing only, with no visual cues.
For personal stories about adults who received a cochlear implant see:
To read this Personal Story you will need Adobe Acrobat Reader version 5 or above. This is free software that can be downloaded at Adobe Web site:
Bridge To Sound With A ‘Bionic’ Ear
(A book about Cochlear Implants and personal stories of users.)
Hear Again: Back to life with a Cochlear Implant
by Arlene Romoff
The Parents’ Guide to Cochlear Implants
by Patricia M. Chute, Mary Ellen Nevin
Sounds from Silence: Graeme Clark and the Bionic Ear Story
by Graeme Clark
Wired for Sound: A Journey Into Hearing
by Beverly Biderman
The number of college age students with Cochlear Implants has risen dramatically in the last few years. In 1999, the National Technical Institute for the Deaf (NTID) had 29 students with an implant. In 2003, more than 120 students with Cochlear Implants were identified.
Source: Clark, Snell, Wallber from NTID
How is it done?
Surgeons make a small incision behind the ear to be implanted, and then insert a receiver–stimulator, followed by an electrical array that is used to stimulate residual nerve endings in the inner ear. Typically, the operation takes less than two hours and does not require an overnight stay in the hospital. Patients usually wait about 4 weeks before the system is activated. However, most patients return to work and other routine activities before activation occurs.
One of the criteria for successful cochlear implant recipients is listed as “appropriate expectations.” What does that mean? It means that the recipient fully understands what can and cannot be achieved through the implant. The following are some considerations.
Adults who lost hearing before they were three–years–old
If an adult has limited English speaking ability and comprehension due to pre–lingual (before learning language) deafness, then a cochlear implant will not result in immediate comprehension of spoken language. Think of it this way: If you have spoken English all your life and take a plane to Russia, does that make you able to understand Russian even though you can hear it? No. A person who has never heard spoken language will need to go through the long process of learning a new language. It is important for parents to understand this, and for the whole family to commit to the process of language training.
Adults who are born deaf or lose their hearing before learning language may have a limited language base (and the required neural pathways) on which to develop a new language. Remember that children learn languages very quickly. But if there is language deprivation during the early years, the adult may always have language limitations. This is frequently the case with deaf children born to hearing families who do not sign or who do not detect the hearing loss early on. The result is that a pre–lingually deaf adult who receives a cochlear implant may always have limited language comprehension, including difficulty with reading.
The exception is prelingually deafened adults who have used amplification, listening, and speech consistently. These individuals have prepared their brains to receive spoken language. Many of these individuals, drawing on their comfort and skills with spoken language, have made great gains with a cochlear implant (Cochlear Implant Candidacy and Outcomes: 2002 Update by Donna Sorkin, Hearing Loss July/August 2002)
Deaf Children in Deaf Families
Deaf children who are born into a culturally Deaf family may have very little exposure to spoken language, although they are fluent in American Sign Language. These children have been raised in a family that values ASL and Deaf culture. Deaf parents may be very proud of their Deaf child and may consider a cochlear implant as an attempt to impose hearing culture and values on their child. Further, there may be little or no spoken English in the household. To learn to speak, the child with a cochlear implant will need extensive language training outside of the home. The entire family must commit to this process for the best cochlear implant results.
A Period of Adjustment
Some adult cochlear implant recipients have stressed a need for counseling and a period of adjustment after the surgery. For some, the cochlear implant increases the feeling of not belonging. The person may feel like an outsider in both the hearing and Deaf communities. Others have talked about the increased ‘noise’ and of the time required to adjust. As with any major life change, it takes time to feel comfortable. Expecting an adjustment period prior to surgery will make the adjustment easier.
Outcomes difficult to predict, but improving…
Currently, language comprehension after implant cannot be guaranteed. While some people (adults and children) are able to function almost entirely by hearing spoken language (even using the telephone), others only experience an improvement in speech reading (Draft Report, American Speech–Language and Hearing Association). Studies are underway to predict, prior to surgery, the degree of benefit an individual is likely to receive.
For More Information
Cochlear Implants have revolutionized the treatment of hearing loss. For many people, the results have been overwhelmingly positive. However, there are some controversies brewing. See the links below for more information:
Regarding the link between Cochlear Implants and Meningitis from the Food and Drug Administration (FDA):
A response to health risks by the Cochlear Corporation:
The National Association for the Deaf (NAD) position statement and related articles:
The Canadian Response to the NAD position statement:
A Michigan court case involving Cochlear Implants:
A recent CNN article describes the increased risk of meningitis in children with a cochlear implant: