Music performance acoustics and room shape: An investigation employing an images model of room acoustics

Critical listeners often observe that rectangular (shoe box) rooms have “better acoustics” for music than fan shaped rooms of similar size. In this paper we examine the relationship between room shape and some physical aspects of souns fields in the room. The tool for our analysis has been a geometric acoustics (images) model implemented on a microcomputer. Three-dimensional impulse responses have been computed for some simple fan-shaped, reverse-fan-shaped, and rectangular rooms. Various means of graphical display are used to point out those trends in the time and space distributions of the impulse response that are tied to the fundamental shape of the room. Lateralization of the souns field and development of the reverberant field are two acoustical processes in particular that have their roots in the architecture of the space. Drawing on the past two decades of research into the influence that the direction of arriving sound has on listener perceptions and preferences for music, we identify links between the “sound” of a room and its shape.