The first cochlear implant was invented by William House, in 1961. In 1964, Blair Simmons and Robert J. White implanted a single-channel electrode in a patient's cochlea at Stanford University. The modern multichannel cochlear implant was independently developed and commercialized by Graeme Clark from Australia and Ingeborg Hochmair and her future husband, Erwin Hochmair, with the Hochmairs' first implanted in a person in December 1977 and Clark's in August 1978.
The cochlear implant is a surgically implanted neuroprosthetic device that replaces the function of the damaged inner ear. The devices have two parts. One part, the receiver-stimulator, is placed under the skin behind the ear using a small cut. The other, the speech processor, is worn behind the ear like a hearing aid. The outside part is slightly larger than a normal behind-the-ear hearing aid.
The receiver is connected to electrodes, which are put into a part of the inner ear called the cochlea. The surgery lasts approximately 2-3 hours, and the patient will probably go home on the same day. The recovery period can be between 1-4 days. It converts sound in electrical impulses sent directly to your auditory nerve, which carries sound signals to your brain.
Unlike hearing aids, which make sounds louder, cochlear implants do the work of damaged parts of the inner ear (cochlea) to provide sound signals to the brain, by bypassing the normal acoustic hearing process, instead replacing it with electric hearing.
Many people suffer hearing loss because their hair cells in the inner ear or (or cochlea) are damaged. The cochlear implant enables the sound to be transferred to your hearing nerves and enables you to hear. The process is described below:
1. A sound processor worn behind the ear or on the body, captures sound and turns it into digital code. The sound processor has a battery that powers the entire system.
2. The sound processor transmits the digitally-coded sound through the coil on the outside of your head to the implant.
3. The implant converts the digitally-coded sound into electrical impulses and sends them along the electrode array placed in the cochlea (the inner ear).
4. The implant's electrodes stimulate the cochlea's hearing nerve, which then sends the impulses to the brain where they are interpreted as sound.
The implant has two main components. The outside component is generally worn behind the ear, but could also be attached to clothing, for example, in young children. This component, the sound processor, contains microphones, electronics that include DSP chips, battery, and a coil which transmits a signal to the implant across the skin. The inside component, the actual implant, has a coil to receive signals, electronics, and an array of electrodes which is placed into the cochlea, which stimulate the cochlear nerve.
The implant doesn't make you hear normally again, but it can help you with sounds. Most people with severe to profound hearing loss can understand speech in person or over the phone better than they did with a hearing aid. It can usually help with various sounds, including telephones, doorbells, and alarms. Many people also can pick up on speech in noisy places better than they did with hearing aids, or even enjoy music again.
Edited by John Sandham.