Acoustics of buildings is a branch of physics which deals with the design of buildings like cinema halls, concerts halls, auditorium etc, in order to provide a pleasant sound system in the building. Sabine was the first to analyse this aspect of the buildings. He introduced the concept of reverberation time. The phenomenon of persistence of sound after the source has actually stopped producing sound is called reverberation of sound. The time for which sound continues to be heard after the source has stopped producing sound is called reverberation time.
Sabine formula for reverberation time of a hall is T=Σas0.16V
where V is volume of the hall in m3 and Σas is total absorption of the hall.
In particular, reverberation time of a hall is adjusted by providing a few open windows, covering the walls with absorbing materials, using heavy curtains with folds and using upholstered seats in the hall.
Note It has been established that for speech, optimum value of reverberation time is 0.5s and for music, the optimum value of reverberation time lies between 1 to 2s. A room with zero reverberation time is called a dead room.