Estimating reverberation time in classrooms by the power method
Richard D. Godfrey · The Journal of the Acoustical Society of America · 2003
The Sabin equation relates reverberation time to room volume and absorption. If an acoustic source of known power is placed in a room, the absorption is also related to the power per bandwidth, volume, and pressure. Combining the Sabin equation with the power equation and solving for reverberation time yields a relationship for reverberation time as a function of volume, pressure, and the power of the source. This approach has been reported to deviate from the decay method at low frequency. In a laboratory reverberation room, it yielded reasonable results in the frequency range of interest in classrooms. Reasonable results were also achieved in real classrooms in the 500- to 2000-Hz frequency range. Based on these findings, it may be possible to make acceptable reverberation time measurements in less time with less sophisticated instrumentation than the decay method.