Synthesis of room responses using virtual source representation with application in reverberator design

Abstract

Reverberators play a vital role in immersive audio reproduction. Conventional methods for synthesizing reverberation generally are either computationally intensive or ineffective in producing a natural sensation of environmental settings. A synthesis technique is developed using discrete virtual source representation in an effort to overcome these difficulties. In comparison with the finite-element method (FEM) and the boundary-element method (BEM), which rely on complex numerical operations, the present method is based on a simple representation of the sound field with a distribution of discrete simple sources close to the boundary. The complex strengths of the virtual sources are then calculated by solving a frequency-domain least-squares problem. Parameters such as the geometry, size, and wall absorption of the room are naturally incorporated into the synthesis process. The filtering property of human hearing is also considered in a nonuniform sampling procedure to further simplify the computation. Numerical simulations are carried out for a rectangular room model and a concert hall to investigate the effects of room parameters on the synthesis performance. Subjective listening experiments demonstrate that the present technique is capable of rendering remarkable realism of reverberation.