Cochlear implants

There are times when damage to the cochlea (coke-lee-AH) from disease, injury or toxins is so great – and the hearing loss so profound – that a hearing aid offers no assistance. But there is an alternative. The cochlear (coke-lee-AR) implant utilizes electrical impulses to stimulate remaining nerve fibers and significantly improve hearing. During the procedure, one or more electrodes are implanted inside or outside the cochlea. At the same time, a tiny receiver is implanted under the skin, either behind the ear or in the lower region of the chest. Then a wire connecting the electrodes to the receiver is implanted. Directly over the receiver, the patient wears an external transmitter, which is connected to a microphone and a sound processor. Unlike a hearing aid, the cochlear implant receives and passes electrical signals, and allows the patient to hear the rhythms of speech and sometimes the intonation of the voice. In a controlled study, one-fourth of patients with a cochlear implant could repeat two-thirds of simple words in unrehearsed sentences without lip-reading. The cochlear implant cannot restore normal hearing, but, along with lip-reading, allows a greater understanding of speech than is possible by lip-reading alone.