Reverberation Time: Definition, Theory, and Measurement

Abstract

Various definitions of reverberation time and their significance are reviewed. The relations of reverberation time to mode theory (decay rates of the normal modes) and ray theory (time intervals between successive reflections and distribution of absorptive materials within the enclosure) are discussed. Different methods of measuring reverberation time are described and expressions for their accuracy and reproducibility are derived. Variations of reverberation time with location within an enclosure is considered. The subjective significance of different definitions of reverberation time and experimental results for nonexponential decays are discussed. The paper concludes with a brief description of new methods of subjective multidimensional scaling and its relevance to the general problem of acoustic quality.