Cochlear implants can often improve the hearing of people with severe to profound hearing loss who are not helped by hearing aids. Cochlear implants are similar to powerful hearing aids, but part of the cochlear implant is surgically implanted. How do cochlear implants work?

Each cochlear implant has an external component and an internal component that is surgically implanted. The external part of the cochlear implant holds the battery and has the audio receivers that transmit sound to the internal part of the implant. The transmitter part of the external portion is held in place over the internal part of the implant with a magnet.

The external portion of the cochlear implant includes a microphone that picks up sound in the person’s environment and a processor that converts the sounds to electrical signals. The part of the implant that receives sound resembles a behind-the-ear (BTE) hearing aid. It is connected to the processor with a wire. The processor filters and analyzes the sounds. The electrical signals are sent through a wire from the processor to the transmitting coil which is a radio transmitter.

The internal part of the cochlear implant is sometimes referred to as the receiver/stimulator. The internal component includes a radio antenna that allows the internal component to receive signals from the external part of the implant. The internal portion of the cochlear implant includes a microcomputer and an array of electrodes. The receiver sends the electrical signals through a wire that leads to the electrodes which are positioned in the fluid inside the cochlea.

When the external part of the cochlear implant processes sound, it converts the sound into electrical signals that are sent in the form of FM radio signals to the internal component’s antenna. In response to the radio signals, electrical signals are delivered to the cochlea through the array of electrodes. These signals stimulate the cochlear which sends the auditory signals to the auditory nerve. The nerve signals from the auditory nerve are what the brain perceives as sound.

Therefore, the cochlear implants are actually quite different from hearing aids. Hearing aids can only amplify sound. Cochlear implants convert sound to electrical signals that it uses to directly stimulate the cochlea and auditory nerve. People who have severe or profound hearing loss often do not receive much benefit from hearing aids. However, cochlear implants often effectively treat severe and profound hearing loss though it is important to remember that cochlear implants do not restore normal hearing.