A STUDY OF THE REDUCTION OF TRANSMITTED SOUND THROUGH A PARTITION WALL BY APPLYING THE METHOD OF A.N.C. : A reduction of secondary radiate sound by use with a loudspeaker

Abstract

In this paper, we applied the method of active noise control (A.N.C.) to the reduction of transmitted sound through a partition wall. The control frequency was decided in around resonant frequency, because generally the frequency was reduced sound insulation. Then, we tried to control of 63Hz (1/1 Oct.), by two methods, output of opposite phase signal, and A.N.C. of the vibration of a wall by a loudspeaker. As a results, we show that sound pressure level differences of method by A.N.C. are increased up to 20dB which are controlled in 63〜80Hz (1/3 Oct.).