A microphone is a type of transducer that converts sound waves into electronic signals. These signals are then transmitted to a preamplifier which enables the signal to be recorded or reproduced over a loudspeaker. Microphones can be standalone or be embedded within another device such as personal computers where they are used in voice recording, online chat applications and speech recognition. Telephones and headsets also have microphones built into them. Microphones are used in a wide range of applications including public address systems, concert halls, radio and television broadcasting and video production.