Device for converting sound waves into electric power that has wave characteristics essentially similar to those of the sound.
By proper design, a microphone may be given directional characteristics so that it will pick up sound primarily from a single direction, from two directions, or more or less uniformly from all directions. In addition to their use in telephone transmitters, microphones are most widely applied in hearing aids, sound-recording systems (principally magnetic and digital tape recorders), dictating machines, and public-address systems.