MICROPHONE: The transducer which transforms sound energy into electrical energy

Microphone is a generic term that is used to refer to any element which transforms acoustic energy (sound) into electrical energy (the audio signal). A microphone is therefore one type from a langer class of elements called transducers (device that changes energy from one form into another, in this case, acoustic energy into electrical energy). The microphone is the first link in the audio chain and is therefore critical to the overall performance of a sound system. The fidelity with which a microphone generates an electrical representation of a sound depend, in part, on the method by which it performs the energy conversion. Historycally, a number of different methods have been developed for varying purposes, and today a wide variety of microphone types may be found in everyday use.Improper selection of microphones may prevent the rest of the system from functioning to its full potential. Proper selection of microphones depends on an understanding of basic microphone characteristics and on a knowledge of the intended application. To be most effective, a microphone must be matched both to the desired sound source (voice, musical instrument, etc.) and to the sound system (PA system, tape recorder, etc.) with which it is used. There are five areas of microphone characteristics that must be considered when selecting a microphone for a particular application. They are:
1) the operating principle of the microphone
2) Frequency response
3) Directional characteristics
4) the electrical output of the microphone
5) the physical design of the microphone