Beyond reverberation time: Toward a new geometric approach to room acoustics

Abstract

The limitations of the most prevalent parameter in room acoustics—reverberation time—are numerous, and some arise from absorption coefficients measured in reverberation chambers and, more broadly, assumptions of a diffuse field. The result is that material performance metrics and reverberation time prediction—whether calculated or simulated—are reliable over a more limited range of room types than is often recognized in practice. In this work, a new approach that could widen this range is presented via a potential new geometric view of room design. Room geometry has the potential to seamlessly connect dry, diffuse, reverberant, and focusing spaces (e.g., domes, cylinders) into one range of continuous design possibility. Evidence for the efficacy of this approach will be provided via a scrutinization of the behavior of reverberation time equations, including Sabine's, and empirically via room measurements of a space with and without diffusive boundaries: Studio 2 at the Experimental Media and Performing Arts Center in Troy, NY. Insight will also be lent into strange laboratory results, such as variations in measured absorption coefficients based on splitting and spreading of test samples.