The listener does not hear the sound start to decay until a time \(t_{direct}\) after the sound is turned off (sound is still traveling to the listener for a brief time after the source is turned off)...The listener does not hear the sound start to decay until a time \(t_{direct}\) after the sound is turned off (sound is still traveling to the listener for a brief time after the source is turned off). An approximate equation (due to Wallace Sabine) for calculating reverberation time in seconds is \(T_{r} = (0.16\text{ s/m})V/S_{e}\) where \(T_{r}\) is the reverberation time, \(V\) is the volume of the room in \(\text{m}^{3}\) and \(S_{e}\) is the effective absorption area in \(\text{m}^{2}\).
