A cochlear implant goes on both the outside and inside of your head.
These parts work together to help you hear.
External or outside parts: You will wear a device that looks like a hearing aid behind your ear. It has a microphone that picks up sounds and sends them to a speech processor. The speech processor turns the sounds into a digital signal.
The speech processor sends the signal to a transmitter. This device goes on your head, behind your ear. The transmitter sends the signal to a receiver under your skin. A magnet holds the two together.
Internal or inside part: The receiver is under the skin behind your ear. It sends the signals to electrodes in your inner ear, or cochlea. The electrodes trigger the auditory nerve. This lets your brain notice the incoming sounds.