A new theory for active suppression of reflected sound waves from the walls based on Kirchhoff-Helmholtz boundary integral equation

Abstract

In this paper, a new theory for achieving the active suppression of reflected sound waves from the walls in a room is proposed with its basis on Kirchhoff-Helmholtz boundary integral equation and inverse system theory. By actively suppressing and absorbing the unwanted reflections in the target sound field, the proposed method controls the control sources distributed outside the control region so as to equalize the region to the free field. For this purpose, Kirchhoff-Helmholtz boundary integral equation gives an effective means. Moreover, a method for suppressing the reflected sound waves from a certain part of the boundary is also mentioned. The validity of those methods is demonstrated via computer simulations.