Gradient Microphones

The response‐frequency and directional characteristics of gradient microphones from zero to nth order have been obtained. Higher order unidirectional microphones have also been developed. The directivity increases with the order which means corresponding discrimination against random sound. The accentuation of the low frequency response, when the distance from a small source is less than a wave‐length, increases with the order and the wave‐length. This feature may be used to obtain high discrimination against distant sounds in a close talking microphone. The amount of discrimination increases with the order of the microphone.