What is a cochlear implant?
A cochlear implant is a device that provides direct electrical stimulation to the auditory nerve. In sensorineural hearing loss where there is damage to the tiny hair cells in the cochlea, sound is not effectively sent to the auditory nerve. With a cochlear implant, the damaged hair cells are bypassed and the auditory nerve is stimulated directly. The cochlear implant does not result in "restored" or "cured" hearing. It does, however, allow for the perception of sound and when combinbed with proper rehabilitation, can enable both children and adults to achieve a very significant improvement in understanding of speech. The ultimate level of functioning with the implant is highly variable across individuals, but today, with the breakthroughs in technology, combined with the proper rehabilitation, most adults and children benefit tremendously. Implants, coupled with intensive auditory, speech, and language training can help congenitally deaf young children acquire highly intelligible speech and oral language skills. Early implantation provides exposure to sound during the critical period when language is learned by typically developing children. Today implants are routinely placed in children beginning at 12 months and in certain instances, even younger. The procedure is often described as “miraculous” by people who have received them, and by their families and loved ones.
How does an implant work?
There are several different implants available in the United States today; the three most commonly used are, in alphabetical order, Advanced Bionics, Cochlear Corporation, and Med-El. Each manufacturer has slightly different components and different ways of working, as well as differing “speech processing strategies.” The following is common to most cochlear implants: the implant consists of both internal and external components. The external components include a microphone that picks up sound in the environment, a speech processor that is a mini-computer that determines what part of the signal is sent to the electrode array, and a transmitter that sends the selected information to the internal components. The receiver/stimulator, also an internal component, is located just beneath the skin behind the ear and “receives” the information sent by the transmitter and converts the signal into electric impulses. These impulses are sent to the electrode array which is the part that is implanted within the cochlea, which then electrically stimulates the auditory nerve directly.
What steps are involved in getting a cochlear implant?
The first step is to have a conversation with your audiologist about whether or not you are a candidate for an implant. Make sure that your audiologist is familiar with the current candidacy criteria. If your audiologist feels you may be a candidate, or does not have enough information, your next step is to make an appointment at a cochlear implant center. At the center, you will have discussions with a variety of specialists including an experienced cochlear implant surgeon and the center’s audiologists. While the process is different at each center, you will typically be scheduled for a number of medical tests and audiological evaluations to determine your candidacy. At the center you should expect to be able to discuss the different types of cochlear implants, to discuss the center’s particular approach and schedule of post-surgical procedures, and have an opportunity, if you wish, to meet with other patients who have used that center.
Once the decision is made that you or your child are a good candidate for a cochlear implant, other decisions will also need to be made in consultation with the implant team. Two decisions are what type of implant to receive and whether you should have one or two implants. Different centers may have different opinions/experiences in these issues and you should expect to be able to be told the rationale for all of their thoughts and opinions.
Who is a candidate for a cochlear implant?
A cochlear implant is typically considered for children and adults with severe and profound sensorineural hearing loss, when after a trial of use of appropriately fit amplification it is felt that more benefit will be obtained with the implant than with the amplification.