In-the-ear (ITE), aid is custom designed to fit the wearer's ear. Inconspicuous once in place, they fit comfortably and securely inside the ear or ear canal, in order to most closely imitate the natural hearing process. These one-piece models have no cords or wires. Instruments are self-contained; a miniature microphone, amplifier and speaker inside the instrument carry amplified sound directly to the ear canal and auditory system.