Index of content:
Volume 105, Issue 3, March 1999
- ARCHITECTURAL ACOUSTICS 
105(1999); http://dx.doi.org/10.1121/1.426710View Description Hide Description
In practice, impulse responses in enclosed spaces are calculated with algorithms that are based on the ray tracingmodel, the mirror image sourcemodel, or a mixture of both. Using those algorithms, however, the wave character of sound propagation is not properly taken into account and complex boundaries cannot be included. This paper presents an alternative approach adopted from the seismic imaging field. The proposed model is based on the concept of wave field extrapolation. Absorption properties of the boundaries can be specified in detail by means of reflection matrices. Propagation between boundaries is formulated by propagation matrices. Impulse responses along an array of receivers are numerically simulated by executing a sequence of matrix multiplications that can be interpreted as generalized spatial convolutions. Diffraction phenomena due to the finiteness and irregularity of the boundaries are correctly taken into account. The proposed algorithm is illustrated on a two-dimensional configuration. Results are compared with those of conventional models and with measured data. A discussion on computing time is included. In addition, the proposed algorithm leads to new directions in the analysis of measurements in enclosed spaces. The proposed algorithm implies a new concept for dereverberation of recordings that are made in complex acoustic surroundings, using microphone arrays.