A cochlear implant is an electronic device that is implanted into the inner ear and is used to restore hearing in patients who have severe to profound hearing loss. In patients with normal hearing, sound is collected by the external ear and funneled down to the eardrum.
The sound waves then are carried through the middle ear by the middle ear bones (the ossicles). The sound pressure waves are then converted to nerve signals within the inner ear (the cochlea). A cochlear implant bypasses the normal sound conduction mechanism through the external, middle, and inner ear, and directly stimulates the auditory nerve.
An implant does not restore or create normal hearing. Instead, under the appropriate conditions, it can give a deaf person a useful auditory understanding of the environment and help him or her to understand speech. Cochlear implants were approved by the Food and Drug Administration (FDA) in the mid-1980s and are covered by insurance policies, Medicare, Medicaid, and Vocational Rehabilitation. There are now more than 60,000 patients worldwide who have received cochlear implants.
Who is a candidate for a cochlear implant?
Patients have to be so hard of hearing that a hearing aid is of little benefit. For most patients, a cochlear implant will not work as well as a hearing aid. The most common groups of patients who benefit from a cochlear implant are:
Children who are born deaf
Young or middle-aged adults with hearing loss due to genetic causes, autoimmune disease, or unknown reasons; and
Older adults with progressive hearing loss due to aging or noise exposure
However, the only way to determine whether or not a patient would benefit from cochlear implant is to be evaluated by the implant team of physicians and audiologists.