A cochlear implant is a small, complex electronic device that can help to provide a sense of sound to a person who is profoundly deaf or severely hard-of-hearing. The implant consists of an external portion that sits behind the ear and a second portion that is surgically placed under the skin. It has A microphone, which picks up sound from the environment. A speech processor, which selects and arranges sounds picked up by the microphone. A transmitter and receiver/stimulator, which receive signals from the speech processor and convert them into electric impulses. An electrode array, which is a group of electrodes that collects the impulses from the stimulator and sends them to different regions of the auditory nerve.