High spatial resolution scanning for experimental room-acoustic measurements in scale models

Abstract

This paper presents an experimental study of low frequency behavior of sound propagation in acoustically coupled volumes. The experiments are carried out in an eighth-scale model of two coupled volumes with an automated high spatial-resolution scanning system. Both sound pressure and three-dimensional sound intensities are automatically measured in terms of room impulse responses at each scanning positions over densely defined two-dimensional grids covering the entire areas of the two coupled rooms that enable the analysis and visualization of sound energy and sound energy flows. Through these measurements, and with the aid of a predictive computational model, this paper will discuss low frequency modal behaviors of sound energy flows within one of two coupled volumes. As such, the distribution of potential and kinetic energies, as well as that of active and reactive sound intensities within the coupled space will be separately analyzed. The distributions of intensity vector fields are compared through computational simulation. Consequently, a discussion on possible discrepancies in modal distributions between the computational and experimental results rounds off this paper.