Digital waveguide modelling of room acoustics: comparing mesh topologies

Digital waveguide models have been used successfully as a partial alternative to time domain models based on the wave equation in the fields of musical acoustics and sound synthesis. 2D and 3D rectilinear topologies of unit delay waveguides have been used to model plates, membranes and acoustic spaces. This paper introduces a more accurate model of wave propagation using a mesh based on a triangular decomposition of the 2D plane. Excitation of the mesh with an appropriate input signal results in an impulse response for the modelled room. Wave phenomena such as diffraction, reflections and interference are natural consequences of the model and can be clearly demonstrated and observed. The low frequency resonances of the modelled room can also be shown. The triangular mesh offers a significant improvement in its frequency response over that of the rectilinear mesh.