ISBN 9783843902007

978-3-8439-0200-7, Reihe Elektrotechnik

Christian Borß
An Improved Parametric Model for the Design of Virtual Acoustics and its Applications

183 Seiten, Dissertation Ruhr-Universität Bochum (2011), Softcover, A5

Zusammenfassung / Abstract

In this thesis, a parametric model for the design of virtual acoustics was developed. Conventional perceptual approaches typically employ two rendering blocks for modeling the early reflections and the late reverberation. In our approach, a third rendering block was introduced for the higher-order reflections. The unobtrusive and pleasant acoustics, which are produced by the proposed model, are due to the consistency between the three rendering blocks. Consistency is accomplished, because all three blocks use the same input parameters, namely the size of the simulated shoebox room, the frequency-dependent reverberation time, and the echo density profile. Detailed physical parameters, which are required for the subsequent rendering of the sound field, are derived directly from the three given input parameters. As such, our new approach is significantly different from the conventional methods, since it does not purely simulate an acoustic scenario but because it aims to perceptually synthesize the acoustic scenario.

With the same increasing density of reflections and processed with the same filters, the synthesized early reflections and the higher-order reflections produce a very consistent auditory impression. While both rendering blocks are realized by means of an image source model, they differ in one aspect: the positions of the higher-order image sources are randomized and do not depend on the current position of the sound source. This does not only avoid unpleasant coloration, but also yields a smooth transition between early reflections and late reverberation due to its statistical properties. An optimal temporal alignment of the late reverberation tail and the simulated specular reflections is achieved by a novel combination strategy.