- A small or miniature speaker which is intended to be placed within the outer ear, or immediately surrounding it. It is utilized for private, portable, or enhanced listening. A pair may be used for stereophonic listening. Also called headphone (1).
- An earphone (1) specifically designed for use with a hearing aid amplifier. Also called headphone (2).
- An earphone (1) located in the handset of a telephone, which enables listening. Also called receiver (4), or telephone receiver (1).
- noun part of the headset for a radio or other audio equipment, which is put on the ear to listen to a transmission or signal