A cochlear implant is a small electronic device that helps people hear. It can be used for people who are deaf or very hard of hearing.
A cochlear implant is not the same thing as a hearing aid. It is implanted using surgery, and works in a different way.
There are many different types of cochlear implants. However, they are most often made up of several similar parts.
- One part of the device is surgically implanted into the bone surrounding the ear (temporal bone). It is made up of a receiver-stimulator, which accepts, decodes, and then sends an electrical signal to the brain.
- The second part of the cochlear implant is an outside device. This is made up of a microphone/receiver, a speech processor, and an antenna. This part of the implant receives the sound, converts the sound into an electrical signal, and sends it to the inside part of the cochlear implant.
How do cochlear implants work?
A cochlear implant operates using two main components: An external part that hooks over the ear and a surgically implanted internal part. The two components are coupled using a powerful magnet.
The external component of a cochlear implant contains a microphone, a speech processor and a transmitter. The microphone and speech processor are housed in a small unit that looks like a behind-the-ear hearing aid. A small wire usually links them to the transmitter, which is positioned over the internal part of the device. The microphone picks up acoustic sounds and sends it to the speech processor. The processor analyzes and digitizes the signal before sending it to the transmitter. The transmitter then codes the signals and sends them to the implanted receiver via the magnetic coupling.
The internal part of a cochlear implant includes a receiver, which is located under the skin on the temporal bone, and one or more electrode arrays. The receiver collects the signals from the transmitter and converts them to electrical pulses. It then dispatches the pulses to the electrodes that have been inserted deeply into the inner ear. These electrodes directly stimulate the auditory nerve throughout a portion of the cochlea and the brain then interprets these signals as sound.