A coupled volume system is typically defined as two spaces that are joined by a common acoustically transparent surface, known as a coupling aperture. In coupled volumes, if the times required for sound decay in each space are unequal, there will be excess energy in one of the spaces during the decay process. This will lead to the phenomenon known as double-slope decay, which can produce desired acoustic qualities within a space. The effect of double-slope decay in complex shapes with complex coupling apertures is a research area of great interest to modern acousticians.

The purpose of this research is to determine the effectiveness of coupled volumes for use in concert halls and other multi-use performance spaces. Coupled volumes can be understood more fully by analyzing the factors that create the double-slope decay. The variables that affect the behavior of coupled volumes are coupled volume size, main volume size, aperture size, and the ratio of absorption between the two spaces.