How does a microphone pick up sounds?

A microphone converts sound into a small electrical current. Sound waves hit a diaphragm that vibrates, moving a magnet near a coil. In some designs, the coil moves within a magnet.

15th October 2013

Asked by: Luigi Filletti, Malta

A microphone converts sound into a small electrical current. Sound waves hit a diaphragm that vibrates, moving a magnet near a coil. In some designs, the coil moves within a magnet.

Other microphones, such as condenser microphones, work on the principle of capacitance. Capacitors consist of parallel conducting plates that store charge and are used to smooth out signals like voltage variations in a power supply. In a condenser microphone, the incoming sound vibrates one plate of a capacitor. The varying capacitance is converted into a corresponding electrical signal.