Sound is a particular type of wave in which a variation of pressure that is induced by a vibrating body (that is, a sound source) propagates in the surrounding medium (usually air). Some examples of sound sources include the following:
- Musical instruments in which the vibrating part can be a struck string (such as a guitar), or rubbed with a bow (such as the violin).
- Our vocal cords that are made to vibrate from the air that comes out of the lungs and give rise to the voice.
- Any phenomenon that causes a movement of air (such as the beating wings of a bird, an airplane that breaks down the supersonic barrier, a bomb that explodes, or a hammer beating on an anvil) having appropriate physical characteristics.
To reproduce sound through electronic equipment, it is necessary to transform it into an analogue sound that is an electric...