The study of sound in the built environment is finding more awareness in the 21 st century. As this awareness has increased, and as computing power has grown, the method of computer modeling for studying room acoustics in such settings as classrooms, offices, and performances spaces has taken great strides in recent years. Of particular interest has been the study of the coupled volume space due to its unique ability to provide contrasting acoustical phenomenon. A coupled volume room is generally defined as a space consisting of a large main volume containing high levels of sound absorption connected through small sonically transparent apertures to a smaller coupled volume with lower absorption. When a sound source is placed in the main volume, this configuration may lead to sound energy being trapped in the coupled volume, which is then released back into the main space at a later time. The delay in sound energy from the coupled volume results in a double-sloped sound decay in the main volume, resulting in intriguing acoustical phenomenon not typically seen in single volume spaces. The real world application of this type of space is most commonly found in concert hall settings. The use of computer modeling to study this relatively complex type of space is a comparatively new development, and the limits of the method have yet to be fully explored. This research focuses on determining the effects of the architectural parameters, absorption level and aperture size, on the room acoustics in coupled volume spaces. A coupled volume concert hall computer model was constructed and analyzed in order to determine these effects. Comparative analysis of several configurations of the model reveals that increased absorption in the coupled volume decreases double slope effect, while the effect generally peaks for a relatively small aperture opening size. Copyright ASCE 2006.