Normal hearing aids amplify the sound from the environment and return it to the ear. With severe damage to the hair cells in the inner ear, hearing is not possible no matter how much the sound is amplified. In other words, a normal hearing aid is not enough for severe hearing loss. However, because the cochlear implant converts sound into electricity and transmits it to the auditory nerve, it provides hearing even in cases of deafness that occurs after severe hairy cell loss. The cochlear implant consists of two main parts, the inner and the outer. The outer part consists of a receiver (microphone) and a processor, and is attached to the earlobe and scalp. The outer part can be inserted and removed as well as hearing aids. The inner part consists of two parts (stimulator and electrode) placed in the inner ear and under the skin by surgery. The microphone picks up the sound, filters it and processes it. The processor contains filtered audio digital information and transmits it to the internal part. The inner part of the sound that is digitally transmitted here is converted into electricity, and then transmitted to the electrode placed in the inner ear. The electrodes, which are arranged according to the frequency of the sound, bypass the damaged hair cells and electrically stimulate the auditory nerves and transmit the sound to the brain.