Headphones (also known as earphones, earbuds, stereophones, headsets, or by the slang term cans) are a pair of tiny loudspeakers, or less commonly a single speaker, with a way of holding them close to a user's ears and a means of connecting them to a stereophonic or monophonic, or binaural audio-frequency signal source such as an audio amplifier, radio, etc. In the context of telecommunication, the term headset is used to describe a combination of headphone and microphone used for two-way communication, for example with a telephone.
Since the introduction of the Walkman and later the iPod and other MP3 players headphones have become a very popular way of listening to stereo, especially among the younger generation. This is despite the fact that headphones are not really suitable for stereo, which is a system designed specifically for loudspeaker reproduction and relying primarily on loudness differences between channels for spacial effect. Headphones are ideally suited to binaural recordings, especially dummy head recordings which use phase difference or time delay for sound location. It is because of this fact that listening to stereo on headphones tends to produce the effect of sound coming from 'within the head', as well as extreme pulling to one side leading to a sense of deafness in the other ear, for example on cymbals which might be reproduced through one channel predominantly, though our brain expects them to be heard by both ears, though muffled and delayed in one by the shadow effect of the head. The effect can be alleviated to some degree by use of a shuffler or crossfeed device.
