Headphones are also known as earspeakers, earphones or, colloquially, cans. Headphones let a single user listen to an audio source privately, in contrast to a loudspeaker, which emits sound into the open air for anyone nearby to hear.
They are electroacoustic transducers, which convert an electrical signal to a corresponding sound. Headphones are a pair of small loudspeaker drivers worn on or around the head over a user's ears.
