WANG Jiqing 

(Institute of Acoustics, Tongji University Shanghai 200092) 

Received Mar. 19, 2007 

Revised May 25, 2007

Abstract  The traditional Chinese theatre was often built with a courtyard. In such open-top space, the absence of a roof would mean little reverberation and non-diffused sound field. Acoustically the situation is quiet different from that of any enclosed space. Therefore, the classic room acoustics, such as Sabine reverberation formula, would no longer be applicable, due to the lack of sound reflections from the ceiling. As the parameter of reverberation time T30 shows the decay rate only, it would not properly characterize the prominent change in the fine structure of the echogram, particularly in case of a large reduction of reflections during the decay process. The sense of reverbrance in a courtyard space would differ noticeably from that of the equivalent 3D-T30 in an enclosed space. Based upon the characteristic analysis of the sound field in an open-top space, this paper presents a preliminary study on the acoustics of the courtyard theaters.

PACS number: 43.55