Since the development of cochlear implants in the 1960s, more than 3000 persons—children and adults—have been implanted with a variety of these devices. Controversy exists on several issues, including determination of appropriate candidates, selection of a single-channel or multichannel device, suitable preimplantation and postimplantation assessments, and rehabilitation procedures.
Some investigators have claimed a spectacular return of hearing in deaf persons with cochlear implants. Unfortunately, to date, no person can be documented to have had normal hearing restored by this device. On the other hand, the cochlear implant does provide significant benefits for some in a variety of ways.
Currently, we do not have the degree of understanding of disease mechanisms and disorders of function for hearing disorders that is common to other human organs and functions. This is partly because the organ of hearing is encased in bone and cannot be visualized during life. In addition, there are only