DEVICE FOR RECOGNIZING MOVING DIRECTION OF MOVING SOUND SOURCE

摘要

PURPOSE:To ensure the recognition of the moving direction, by providing a pair of microphones in parallel with the moving direction of the moving sound source, moving the maximal position of the mutual correlation function curve of the detected outputs to the direction corresponding to the moving direction of the moving sound source. CONSTITUTION:The noise detected signals LA and LB from the microphones 3A and 3B are imparted to filters 11A and 11B so as to pass only the frequency band which largely includes the noise part of an aircraft 1 to be measured and to remove the high frequency component which gives adverse effects when A/D converter circuits 12A and 12B are variably operated. The A/D converter circuits 12A and 12B send out digital waveforms signals S1A and S1B so that the positive part of the noise waveform of the aircraft 1 is a logic ''1'' and the negative part thereof is a logic ''0''. The output S1A is stored in a mutual correlation function computing circuit 13 for the time period required for the computation. The output S2A is imparted to the computing circuit 13 through a delay circuit 14, and the mutual correlation function is computed.