A cochlear implant is a surgically implanted electronic device that can restore useful hearing and provide improved communication abilities for individuals who receive little or no benefit from appropriately fit hearing aids. A cochlear implant transforms sound into electrical signals and uses those signals to bypass damaged portions of the inner ear and directly stimulate the hearing nerve.
How cochlear implants work
A portion of the cochlear implant is surgically implanted in the inner ear and the other part is worn externally behind the outer ear, much like a behind-the-ear hearing aid. Cochlear implants are designed to bypass the hair cells of the cochlea that are not functioning and provide direct stimulation to the auditory nerve. This is very different from a conventional hearing aid.
There are a number of cochlear implant devices currently available. All systems consist of an external piece called the speech processor and an internal piece called the implant, which is surgically inserted into the cochlea and stimulates the hearing nerve. The speech processor converts sound into an electrical signal and transmits sound using FM waves to the internal implant. The electrical signal stimulates the auditory nerve fibers, and that information is sent to the brain. The cochlear implant is designed for individuals who receive little benefit from hearing aids. The FDA approves cochlear implants for children as young as 12 months.
The implantation process
In order to be deemed a candidate for a cochlear implant, a patient must receive a cochlear implant candidacy evaluation. A patient will be referred for an evaluation based on his or her hearing test. These appointments can be scheduled at Henry Ford Hospital in Detroit or at Henry Ford West Bloomfield Hospital.
During the two-hour appointment, a patient’s hearing while using hearing aids will be evaluated. Some tests will be run on the patient’s hearing aids and in some cases the patient will be asked to wear a pair of the clinic’s devices. Words and sentences will be played from a speaker in a sound booth and the patient will be asked to repeat what they are able to hear. This portion takes approximately one hour.
The remainder of the appointment consists of an in-depth discussion regarding cochlear implants. This will involve a description and model of the device, discussion of the surgery and how the implant works, and a discussion of the device options and companies.
If it is determined the patient meets the FDA criteria for a cochlear implant, the process of insurance verification will begin. During this process the audiology staff will work with the cochlear implant manufacturers to obtain information on the patient’s coverage from their insurer. The information will include whether it is covered and if it is, how much, if any, coinsurance the patient will be required to pay. This process can take anywhere from a week to several months.
What to bring:
- The patient’s hearing aids (if applicable)
- The patient’s insurance card or cards
- The patient’s driver’s license or other form of identification
- A copy of the patient’s hearing test if performed outside the Henry Ford Health System
Otologic candidacy evaluation
Once deemed an audiologic candidate, an appointment will be scheduled with one of our three surgeons specializing in cochlear implant surgeries. The surgeons will evaluate the patient for surgical candidacy. Tests including X-rays and MRIs may be ordered in addition to a physical examination and counseling to ensure suitability and motivation to participate in the process. Required vaccinations, along with their schedule, will also be discussed. It is important that the candidate understand what the implant will and will not do and also understand the commitment required for care and follow-up services.
Cochlear implant surgery
During the surgery, an incision is made behind the ear, and a portion of the mastoid bone is removed. This leads to the middle ear space where the opening to the cochlea (organ of hearing) is visible. A small area is exposed in the cochlea and the electrodes are inserted. These electrodes will in turn stimulate the hearing nerve. The operation typically takes a few hours. The vast majority of procedures are done on an outpatient basis.
The initial activation of the cochlear implant will occur 4-6 weeks after surgery. Most patients have a follow-up schedule of: two weeks following activation, one month, three months, six months and annually.
Both children and adults receive extensive rehabilitation services from audiologists, speech-language pathologists, teachers and counselors. There is an adjustment period where a cochlear implant user learns to utilize the implant and to incorporate and process the sounds they are hearing.
Benefits of the cochlear implant
Cochlear implants do not provide normal hearing, but for many patients a cochlear implant can aid in communication by improving speech-reading ability. Results vary among individuals, depending on factors such as age at time of hearing loss, status of the remaining auditory nerve fibers, and auditory training.
Who is best suited for a cochlear implant?
Research is constantly providing new information and technology resulting in changes in cochlear implant procedures and instrumentation. It is generally agreed that the best adult candidates are those who:
- Have moderate to profound hearing loss in both ears
- Have had limited benefit from hearing aids
- Have no other medical problems that would make the surgery risky
- Have a strong desire to be part of the hearing world and communicate through listening, speaking, and speechreading.
Children can also be candidates for cochlear implants. Children as young as 12 months of age have received cochlear implants, and the potential exists for successful implantation at younger ages. It is generally agreed that the best child candidates are those who:
- Have profound hearing loss in both ears
- Receive little or no useful benefit from hearing aids
- Have no other medical conditions that would make the surgery risky
- Are involved (when able), along with their parents, in all aspects of the informed consent process
- Understand (when able), along with their parents, their individual roles in successful use of cochlear implants
- Have (when able), along with their parents, realistic expectations for cochlear implant use
- Are willing to be involved in intensive rehabilitation services
- Have support from their educational program to emphasize the development of auditory skills.
Additional information can be obtained at the following websites: