ELECTRONIC SILENCER SYSTEM

PURPOSE:To attain silencing with high accuracy for non-stationary noise generating on a propagation path by suppressing an acoustic feedback from an added sound source to a microphone which detects a propagation sound wave from a noise source. CONSTITUTION:In a propagation path 1, sensor microphones M1 and M1', the characteristic of which are made uniform, at the same distance position from an added sound source S are provided, and the phases of outputs are set reversely with each other, then being inputted to an adder circuit 20. The propagation sound waves from the noise source detected with the microphones M1 and M1' are converted to electrical signals, and are inputted through the adder circuit 20 and an AD conversion part 24, and input signals are converted to digital signals based on a transfer function given from a control part 30 by a digital filter 29. A driving signal is impressed through a DA conversion part 26, and the sound wave in order to negate the propagation sound wave emitted from the noise source is radiated from a speaker S. The propagation sound wave from the added sound source S detected by the microphone M1 is erased electrically with the adder circuit 20, thereby an oscillation state being suppressed.