|n.||1.||(Physics) An instrument for converting sounds into electrical signals, for the purpose of recording or amplifying the sounds. It produces its effects in various ways, as for example by the changes of intensity in an electric current, occasioned by the variations in the contact resistance of conducting bodies, especially of imperfect conductors, under the action of acoustic vibrations. Other forms of microphone may use changes in capacitance or other phenomena to transduce the sounds into electrical signals.|
|Noun||1.||microphone - device for converting sound waves into electrical energy|
|(hardware, audio)||microphone - Any electromechanical device designed to
convert sound into an electrical signal.|
A microphone converts an acoustic waveform consisting of alternating high and low air pressure travelling through the air into a voltage. To do this it uses some kind of pressure or movement sensor. The simplest kind of microphone is actually very similar in construction to a loudspeaker.
The analogue electrical 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.