ELECTRONIC NOISE SILENCING SYSTEM

摘要

PURPOSE:To obtain the electronic noise silencing system of high sound silencing effect by generating the sound wave of the same sound pressure in opposite phase by performing adaptive control for the propagated sound wave from a noise source by computer system with a built-in digital filter. CONSTITUTION:In the propagation path 1 of the sound wave, sensor microphones M1, M2 to detect the propagated sound wave from the noise source are arranged respectively at the upstream side and the downstream side of the standard of a speaker S as an additional sound source. At an adding point 20, the output signals of the microphone M1 and a sound feedback controlling digital filter 22 are added together in the opposite phase. The output signal of the adding point 20 is inputted to an adaptive digital filter 2 and a controller part 10. The output signal of the microphone M2 is inputted as an error signal E to the controller part 10. Thus, the propagated sound wave from the noise source can be effectively eliminated at the position of the microphone M2.