ANSI/ASA S1.16-2000

This American National standard describes procedures for measuring the performance of noise discriminating and noise canceling microphones. The signal-to-noise ratiois measured at 1/3 octave band intervals with the desired test source in a diffuse noise field. The noise canceling performance of the microphone is defined as the noisecanceling index (NCI), a weighted summation of the signal-to-noise ratios. The NCI of the microphone under test can be compared to the required baseline NCI of alaboratory standard pressure microphone.