The distribution of early reflections in hall

The early sound levels in the audience area of an auditorium are significantly effected by the room geometry,the arrangement of absorption treatment and the location of the receiver.The early sound field is non-statistic,different from diffused sound field,therefore it can not be predicted by the diffused field theory.This paper presents the result of measurements in four halls showing the attenuation rate of early sound level with the distance between source and receiver is much larger than the theoretical prediction.