Transient Room Acoustics using a 2.5 Dimensional Approach

摘要

Cavity modes of a finite acoustic domain with rigid boundaries can be used to compute the transient response for a point source excitation. Previous work, considering steady state analysis, showed that for a room of constant height the 3D modes can be computed very rapidly by computing the 2D cross section modes. An alternative to a transient modal approach is suggested, using a trigonometric expansion of the pressure through the height. Both methods are much faster than 3D FEM but the trigonometric series approach is more easily able to include realistic damping. The accuracy of approximating an "almost constant height" room to be constant height is investigated by example.