Interpretation of Early Decay Times in Concert Auditoria

摘要

The early decay time is currently the preferred measure relating to perception of running reverberation or rever-berance. Measured values in 17 concert spaces show a trend for early decay times to be shorter than the reverberation time. Behaviour of the early decay time to reverberation time ratio (EDT-RT ratio) and the spread of EDT within halls was investigated. In some halls there is a linear relationship between early decay time and distance from the source but this characteristic appears neither necessary nor desirable. A series of design features are identified which are responsible for high or low values of the EDT-RT ratio. Among the causes of low values are balcony overhangs and directed reflection design halls. In the last case it is possible to design for a longer than usual reverberation time and thereby create the exciting combination of high intimacy and good reverberance.