Headphones are a pair of small loudspeakers which are designed to be held in place close to a user's ears. Headphones have wires which allow them to be connected to a signal source such as an audio amplifier, radio, CD player, or portable media player. They are also known as stereophones or, colloquially, cans. The in-ear versions are known as earphones or earbuds. 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.