abstract:The method of point matching proposed by Kang and Lee [J. Acoust. Soc. Am. 107, 1153–1160 (2000)] is revisited. This method can be seen as a single-layer potential approach from the viewpoint of imaginary-part dual BEM developed by Chen et al. [J. Chin. Inst. Eng. 12, 729–739 (1999)]. Based on the concept of double-layer potential, an innovative method is proposed to deal with the problem of spurious eigensolution for the Neumann problem. Also, the acoustic mode is analytically derived for the circular cavity. Both the analytical study for a circular case and numerical result for a square cavity show the validity of the proposed formulation.