Spatial sampling of sound pressure in rooms using manual scanning paths

Abstract

In building acoustics and environmental noise, measurements are often needed to determine the spatial average sound pressure level inside a room. This is usually carried out by using mechanical or manual scanning methods, or fixed microphone positions. In comparison with mechanical scanning devices, the human body allows quite complex paths to be traced out in three-dimensional space. This paper assesses the efficacy of some different averaging paths that can be carried out with manual scanning. It is assumed that the sound field is a three-dimensional diffuse field for which the spatial correlation coefficient can be used to determine the variance and the equivalent number of discrete, uncorrelated samples. Numerical simulations indicate the advantages and disadvantages of various manual scanning paths in terms of their equivalent number of discrete, uncorrelated samples.