Microphone

A microphone is an electromechanical device designed to convert sound into an electrical audio signal.

Description
A microphone converts an acoustic consisting of alternating high and low air pressure travelling through the air into a. To do this it uses some kind of pressure or movement sensor. The simplest kind of microphone is actually very similar in construction to an.

The analog audio signal can be fed into a computer's sound card where it is amplified and sampled to convert it into a digital waveform for storage or transmission. This process is known as audio digitization.

History
The first device to digitize audio into a Macintosh computer was the MacRecorder, developed in 1985 by students of the University of California, Berkeley. Starting in October 1990, the Macintosh LC and IIsi were introduced with the Apple Microphone and a built-in microphone port to digitize audio signals, at first only in 8-bit sound. The Macintosh Quadra 840AV was introduced in July 1993 with the Apple PlainTalk Microphone and built-in capability to record and play back 16-bit stereo sound at up to 48KHz. In February 1997, the PowerBook 3400c was introduced with the first built-in PlainTalk microphone.