The effectiveness of manual scanning measurements to determine the spatial average sound pressure level in rooms

摘要

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 scanning devices, fixed microphone positions or manual scanning. In comparison with mechanical scanning devices, the human body allows manual scanning to trace out quite complex paths in three-dimensional space. This paper assesses the efficacy of some different averaging paths that can be carried out with manual scanning. The spatial correlation coefficient is used to determine the variance and the equivalent number of discrete, uncorrelated samples for a three-dimensional diffuse field with an extension to modal sound fields in the low-frequency range. Numerical simulations indicate the advantages and disadvantages of various manual scanning paths in terms of their equivalent number of discrete, uncorrelated samples.