Cochlear implant

A cochlear implant (CI) is a surgically implanted neuroprosthesis that provides a person who has moderate-to-profound sensorineural hearing loss with sound perception. With the help of therapy, cochlear implants may allow for improved speech understanding in both quiet and noisy environments. A CI bypasses acoustic hearing by direct electrical stimulation of the auditory nerve. Through everyday listening and auditory training, cochlear implants allow both children and adults to learn to interpret those signals as speech and sound.

The implant has two main components. The outside component is the sound processor, which contains microphones, electronics that include digital signal processor (DSP) chips, battery, and a coil that transmits a signal to the implant across the skin. It is generally worn behind the ear, though some self-contained sound processors take the form of a pebble-shaped unit worn directly on the side of the head over the implant site, held in place by magnetic attraction to the internal implant. The sound processor could also be attached to clothing, for example, in the case of young children. The inside component is the actual implant, which contains a coil to receive signals, electronics, and an array of electrodes that stimulate the cochlear nerve, which is placed into the cochlea.