random-incidence microphone

7.19  random-incidence microphone. Omnidirectional microphone having essentially a constant sensitivity, as a function of frequency over a specified frequency range, for free-field sound waves that are successively incident on the microphone from essentially all directions with equal probability.

Annotation 1          The frequency response of a random-incidence microphone is similar to that of a true pressure microphone; see 7.20.

Annotation 2          Random-incidence response is essentially equal to diffuse-field response where sound waves impinge on a microphone more or less simultaneously with equal probability from all directions.