Cochlear Implant Services
East Tennessee State University's cochlear implant clinical services are located at the ETSU Nave Language Center in Elizabethton, Tennessee.
Services provided include candidacy evaluation, follow-up implant mapping, aural rehabilitation and speech and language services for patients of all ages.
What is a Cochlear Implant?
A cochlear implant is a device for people with severe-profound hearing loss in both ears. It is surgically inserted in the inner ear. While a hearing aid amplifies sound to make it more audible to the damaged portion of the ear, a cochlear implant directly stimulates the auditory nerve, bypassing the damaged portion of the ear.
How do Cochlear Implants work?
The cochlear implant consists of two distinct pieces; one is an internal receiver/stimulator (surgically implanted) and the second is the external speech processor, which is worn on the outer ear (pinna) and looks similar in appearance to a behind-the-ear hearing aid. Surgery is required to place the internal device. The external components are typically fit several weeks after surgery.
How a Cochlear Implant Works:
- The microphone on the speech processor captures sound and the processor converts the sound to a digital signal.
- The speech processor sends the digital signal across the skin to the internal implant.
- The internal implant changes the signal to electrical energy, sending it to the electrode array in the cochlea.
- The electrodes stimulate the hearing nerve and the brain interprets this stimulation as sound.
Who is a Candidate?
A multidisciplinary team is essential for the cochlear implant evaluation process. A cochlear implant team typically consists of an implant surgeon who looks at the medical history and explains the procedure to the patient. A CT scan is done to make sure that the cochlea is not ossified and is able to hold the electrode bundle. The audiologist will perform the hearing tests to determine the type of loss, and also monitor hearing aid effectiveness to be sure the patient is a candidate for a cochlear implant. A social worker or psychologist is involved to assess feelings toward hearing loss and reasons for seeking a cochlear implant. Based on the recommendations of all these team members it will be determined whether or not a patient is a candidate for a cochlear implant.
The audiologic testing aspect of cochlear implant candidacy includes a battery of tests. These tests are listed below and are used to determine the type and severity of hearing loss. The hearing aid evaluation is done to determine benefit from a hearing aid versus a cochlear implant.
- Pure Tone Testing
- Speech Testing
- Immittance Testing
- Visual Speech Perception
- Vestibular Assessment
- Tinnitus Assessment
- Hearing Aid Evaluation-- 3-6 Months
This step in the process is conducted by a psychologist to assess feelings about hearing loss, reasons for seeking a cochlear implant, and expectations from the implant.
Medical and Surgical Evaluation
The final step before implantation is conducted by the surgeon of the implant team. The ears are assessed to be sure there are no perforated ear drums or ear infection. A CT and MRI will be done to be sure the inner ear can be implanted.
The surgery typically takes one to three hours. General anesthesia is administered. First, an incision is made behind the ear to expose the temporal bone. The surgeon then positions the implant component against the bone. A hole is made in the temporal bone with a microscopic drill, allowing the surgeon access to the cochlea. A small hole is made in the wall of the cochlea and the electrode array is gently guided into the cochlea. The internal receiver is secured in place on the skull bone with sutures and the incision is closed. A sterile dressing is placed on the incision.
Most people stay overnight for observation. This is a relatively low risk surgery, however there are some risks. The most common complication is problems with the wound healing. Less common risks include damage to the nerve that moves the face on the side of the operation, leakage of the fluid around the brain (cerebrospinal fluid), infection of the fluid around the brain (meningitis), temporary dizziness (vertigo), and failure of the device to work.
Post Implant Rehabilitation
Rehabilitation is a required part of implantation.
The primary goals of rehabilitation are to develop and improve:auditory/aural skills
receptive speech and language skills
expressive speech and language skills
incidental learning from the auditory environment
Therapy includes:Multiple weekly aural and speech-language therapy sessions
Daily therapy sessions at school.
A multidisciplinary, dedicated group is necessary. This group includes a SLP (Speech language pathologist), A/V therapist, educators, parents, family, psychologist, and other providers.
The focus depends on patient’s previous experience with sound and listening goals. If a person is implanted who lost their hearing 6 months ago they are probably not going to need much post implant therapy. However if an adult that has been deaf since birth is implanted they will probably need quite a bit of post implant therapy.
Most people do not conduct formal rehabilitation programs with a SLP unless they are not progressing well.
The cochlear implant manufacturer provides rehabilitation tools to be used either at home or in the clinic.
Cochlear Implant Manufacturers
There are three primary companies that are approved by the FDA to provide cochlear implants in the United States. These three companies are Med-EL, Cochlear America, and Advanced Bionics. All of these companies make high quality cochlear implants, no one company is better than another, they just have slightly different features.
For more information on these companies, please visit their websites:
Many parents of deaf children are hearing therefore they have no idea that there is a deaf culture. There is in fact a very active deaf culture in the United States. It is a culture of its own much like any other minority culture. They have their own language, customs, and beliefs. The language they share is American Sign Language. There are schools that are taught using sign language and these children learn about all the same things children in a regular school would as well as Deaf culture. It is also important to note that the Deaf culture as a whole is opposed to cochlear implants. They feel that there is nothing wrong with being deaf and that it is wrong to perform a surgery on a child when there is nothing wrong with them. Deaf people in general view hearing people negatively because hearing people view deafness as a problem that needs to be fixed and hearing people have been trying to fix them their whole lives.
There are two types of deafness. "Little d deaf" and "big D Deaf." Little d deafness is a medical condition. This is Uncle Carl at the family reunion who can’t hear anyone. Big D Deafness is a culture. A Deaf person is one who associates with the Deaf community and embraces Deafness. A person can be born deaf, get a cochlear implant, learn to use speech and never know about Deaf culture. Other people are born deaf, go to a school for the Deaf and live entirely in the Deaf world. This is a decision that is up to each individual.
However, once a person has a cochlear implant, they are not Deaf and they are not hearing. They don’t really belong to either world and may find this challenging. It is important to take this into consideration when deciding whether or not to get a cochlear implant.