chapter  2
17 Pages

Basic Sound Transmission and Operational Forces on Microphones

All modern microphones are used with electrical amplification and thus are designed primarily

to sample a sound field rather than take power from it. In order to understand howmicrophones

work from the physical and engineering points of view, we must understand the basics of sound

transmission in air. We base our discussion on sinusoidal wave generation, since sine waves can

be considered the building blocks of most audible sound phenomena. Sound transmission in

both plane and spherical waves will be discussed, both in free and enclosed spaces. Power

relationships and the concept of the decibel are developed. Finally, the effects of microphone

dimensions on the behavior of sound pickup are discussed.