An indirect boundary integral equation method for architectural acoustics

A numerical method and the resulting computer program for prediction of interior acoustic fields are described. The method is based upon an indirect boundary integral equation formulation of the Helmholtz equation using hybrid layer potentials. The computer program incorporates general boundary conditions directly, and utilizes piecewise constant variable approximations. It is capable of predicting the steady-state response of enclosures with finite impedance boundaries, vibrating boundaries, and multiple interior sources. Numerical results are presented for the acoustic field inside a rectangular prism under various boundary conditions and with various excitations. Apparent limitations of the current program are discussed, and various potential applications in architectural acoustics and noise control are suggested. [Work performed at the Institutt for Teleteknikk, Norges Tekniske Hogskole, Trondheim, Norway and supported by NTNF.]