The Ribbon Microphone

The ribbon microphone consists of a light metallic ribbon suspended in a magnetic field and freely accessible to air vibrations from both sides. The vibration of the ribbon due to an impressed sound wave leads to the induction of an emf. corresponding to the undulations of the incident sound wave. The ribbon is caused to move from its position of equilibrium by the difference in pressure existing between the two sides. In general, the ribbon is made light so that its motion corresponds to the motion of the air particles at very high frequencies. One of the important advantages of this type of microphone as compared with a pressure-operated microphone is that it possesses marked directional properties. This has decided advantages in sound motion picture work.