frontal-incidence microphone

7.18  frontal-incidence microphone. Microphone having essentially a constant sensitivity, as a function of frequency, over a specified frequency range, when in a free field and pointed at the source of the sound; i.e., at frontal incidence.

Annotation              Sensitivity that is essentially independent of frequency is in contrast to that for a true pressure microphone which has increased sensitivity at higher frequencies, varying with the angle of incidence of a sound wave, due to reflection at the microphone diaphragm. A frontal incidence microphone is designed to correct for this disturbance.