Abstract:
This paper deals with a method for controlling the sound field using multiple sound sources and sensors. Methods based on Kirchhoff's integral equation are the effective and promising ones. However, even if the sound pressure on the boundary of the controlled region is given, the sound field inside it cannot be controlled if the frequency of reproduced sound coincides with one of the eigenfrequencies defined by internal Dirichlet problem of the controlled region. For avoiding this problem, a new method using additional control points within the controlled region is proposed in this study. The results of computer simulation showed that sound field can successfully be reproduced by the proposed method. Moreover, a method for distributing the additional control points is discussed. As a result, it is shown that sound field control is properly achieved when the additional control points are so located that a partial area of the region under consideration is controlled based on the sound intensity on the boundary of the area.