SOUND GATHERING DEVICE FOR VIDEO CAMERA

摘要

PURPOSE:To provide a sound gathering device for a video camera capable of performing sound pickup with a high SN ratio corresponding to the fluctuation of a noise environment. CONSTITUTION:A reference microphone 13 is arranged at a position symmetrical to a main microphone 12 for collecting sound relating to the case body wall 11a of the video camera. The output of the reference microphone 13 is inputted to an FIR filter 17 and the output is subtracted from the output of the main microphone 12. An estimation circuit 19 inputs the signals of the reference microphone 13 and a subtracter 18, successively estimates the impulse response of an acoustic transmission system reaching from the reference microphone 13 to the main microphone 12 corresponding to the algorithm of a learning and identifying method and corrects the tap coefficient of the FIR filter at the time of outputting the control signal of a judging circuit 16. Thus, the reference microphone 13 can be installed without influencing the arrangement of a mechanism system inside a case body and the video camera with improved noise resistance can be realized.