How a Cochlear Implant works
A cochlear implant has two parts. The inside part (the implant) is put in during surgery which usually requires a 1 or 2 night stay in hospital. The outside part (the processor) is fitted 4 weeks after the surgery.
The implant is fully under the skin. The body of the implant is called the receiver/stimulator package. It has a magnet at one end and at the other is an electrode array which looks like a wire. The electrode array is threaded into the cochlea by the surgeon. The implant package sits slightly behind and above the ear and is completely under the skin. It feels like a small bump when touched. After surgery there is a small wound behind the ear which takes around 4 weeks to heal.
The processor looks similar to a hearing aid and sits behind the ear. It picks up sound through its microphones and changes this into an electrical signal. A coil connected to the processor uses radio waves to send the electrical signal across the skin to the implant inside. The electrical signals activate the hearing nerve and this is perceived as sound by the brain. The coil sits on the head just above and behind the processor and is held in place by a magnet. It can be easily lifted off for sleeping and bathing.