Linear noise-cancelling microphone
Austin J. Brouns · Defense Technical Information Center (DTIC) · 1976
The document covers the technical details of work performed to improve the performance of noise-cancelling microphones for military use. A major objective was to develop a wider-bandwidth, wider-dynamic-range microphone. Accomplished improvements over predecessor models include 4 dB greater noise-immunity, 12 dB less vibration sensitivity, better electrical shielding, and demonstration that the microphone will operate in extreme military environments and that the 1st order gradient microphone which consists of a ring 'BIMORPH' piezoceramic element and integral pre-amplifier can be hermetically sealed.