A cochlear implant is an electronic device surgically implanted and worked by directly stimulating functioning auditory nerve fibers in the inner ear. Cochlear implants convert sound waves to electrical impulses and transmit them to the inner ear, providing people with severe to profound hearing loss the ability to hear sounds and potentially better understand speech without reading lips. The implant is small and complex device. The implant consists of two parts: the external portion and the second portion. The external portion is situated behind the ear. The second portion is inserted surgically underneath the skin. A cochlear implant is consisted of several part, and these are: a microphone, a speech processor, a transmitter and receiver and an electrode array. The microphone picks up sounds from the environment. The speech processor processes sounds picked up by the microphone. Transmitter and receiver receives sounds and transfer them into electric impulses. The electrode array is a group of electrodes which sends the impulses to the auditory nerve. The cochlear implant does not enable a person to hear, but it gives them a better perception of of the sound surrounding them and helps them understand speech. This is a very good way to help persons who are completely def.