title: A theoretical framework for quantitatively characterizing sound field diffusion based on scattering coefficient and absorption coefficient of walls.
abstract: This paper describes the development of a theoretical framework for quantitatively characterizing sound field diffusion based on scattering coefficient and absorption coefficient of walls. The concepts of equivalent scattering area, equivalent scatter reflection area, average scattering coefficient and average scatter reflection coefficient are introduced in order to express all walls' capability of scatter in a room. Using these concepts and the mean free path, scatter-to-absorption ratio, mean scatter time and diffusion time are defined in order to evaluate degree of diffusion of a space. Furthermore the effect of spatial scattering objects to sound field diffusion is formulated. In addition the time variation of specular and scattered components in a room impulse response is formulated. The verification of these characterization methods was performed with computer simulations based on the sound ray tracing method. The results supported that the ideas presented are basically valid.
authors.affiliation: Department of Construction, Junior College, Nihon University, 7-24-1 Narashinodai, Funabashi, Chiba 274-8501, Japan. hanyu@arch.jcn.nihon-u.ac.jp
authors.forename: Toshiki
authors.initials: T
authors.lastname: Hanyu
mesh_terms: D000042:Absorption; D000162:Acoustics; D005160:Facility Design and Construction; D008962:Models, Theoretical; D009038:Motion; D015203:Reproducibility of Results; D013016:Sound; D013997:Time Factors