Basic purpose of this lecture is to present on Computer Input Device: Microphone. A microphone, sometimes referred to as a mike or mic, is an acoustic to electric transducer or sensor that converts sound into an electrical signal. Microphones are used in many applications such as telephones, tape recorders, hearing aids, motion picture production, live and recorded audio engineering, in radio and television broadcasting and in computers for recording voice, VoIP, and for non-acoustic purposes such as ultrasonic checking.