Optimal design and synthesis of reverberators with a fuzzy user interface for spatial audio

Abstract

Reverberators are key elements in three-dimensional spatial audio reproduction. The richness and spaciousness of reproduced sound can be enhanced with reverberators. Infinite impulse response (IIR) filters such as all-pass or comb filters are commonly used in reverberator design. An inadequate choice of the filter parameters in these reverberators often results in audible artifacts such as metallic and ringing sound. To minimize the effort of trial and error in parameter tuning when designing reverberators, an automatic search procedure based on genetic algorithms (GA) is presented. The architecture of the present reverberator consists of a finite impulse response (FIR) early reflection module and an IIR late reverberation module. To facilitate the choice of filter parameters according to the room modes specified by the user, an intelligent user interface is developed on the basis of fuzzy logic. Subjective listening tests were carried out to assess the performance of the proposed reverberators. The results indicate that, when compared to conventional reverberators, the presented reverberator is capable of delivering natural sounding reverberation.