What is a cochlear implant?
Wednesday, February 12, 2014
A cochlear implant is a device that may be more appropriate than a hearing aid for a patient who has a severe or profound hearing loss and who does not gain significant benefit from hearing aids. It is called a cochlear implant because part of the device is permanently placed into the inner ear or “cochlea” along the hearing nerve during a surgical procedure.
How does a cochlear implant work?
A cochlear implant is very different than a hearing aid for several reasons. First, it is made up of two main components: one is internal, placed by a surgeon. This piece remains in place permanently and it cannot be taken out like a hearing aid. The external component is removable and able to be turned off. When it is on, its microphone and computer processor pick up the environmental sounds and transmit them to the internal component through the skin. The internal piece then stimulates the nerve with electrical impulses, unlike a hearing aid that amplifies sound waves. When the external processor is removed or turned off, the internal electrode is inactive and the ear will not hear any sound at all. This is because the surgery and placement of the internal electrode eliminates all remaining hearing from the implanted ear.
Fitting a cochlear implant is also more involved than fitting a hearing aid. The consultation includes more in-depth hearing testing by an Audiologist, an evaluation by an ear surgeon, along with a CT scan to look at the inner ear structure prior to surgical recommendations. The surgery is done on an out-patient basis but it is completed while the patient is asleep. The surgical site also requires about a one month healing time before the external components can be added and programmed by the Audiologist and the device activated. Follow-up appointments after the initial activation of the cochlear implant are typically more numerous than with a hearing aid and may also involve a Speech Language Pathologist who specializes in cochlear implant patients. Both the Audiologist and the Speech Language Pathologist will work with the patient to teach them how to hear with the cochlear implant because the new sound is quite different. Compared to normal hearing or hearing with a hearing aid, the brain will take some time and practice to learn to hear in a new way.
Not every Audiology office or Ear, Nose and Throat office specializes in cochlear implants, but they can be a good place to start. An initial Audiologic evaluation can often provide enough information to determine whether a patient may be a candidate for further cochlear implant consideration and your Audiologist should be able to make a referral if appropriate.