Illustration of a cochlear implant in the ear, showing how sound travels to the brain. The sound processor is worn behind the ear (shown here next to the ear in green), linked to a transmitting antenna (gray), which transmits sound to a receiver placed under the skin, to the electrode array rolled up in the inner ear duct (in the cochlea). Sound is transmitted to the auditory nerve and to the brain. In some newer implants, both the processor and transmitter are a single unit and sit where the transmitter normally lies on the scalp (not shown).