Three-dimensional microphone array intensity vector sensors for measurement of various acoustical properties in different spatial environment

Abstract

Precise measurement of different acoustical quantities in different spatial environment has been the key in improving sound-quality and reducing acoustical noise from various sources. In this report, a seven-element 3-D microphone array configuration has been used to measure different acoustical quantities (pressure, particle velocity vectors, intensity vectors, energy density, kinetic and potential energy) in various enclosed environments. Microphones in the array were arranged in an inner and an outer triangular fashion with a reference microphone at the center to address high frequency (1–6 kHz) and low frequency (100–1000 Hz) components of sound signals. Statistical distribution of acoustic field has been used for measurements in large and irregular-shaped room. Statistical distribution of acoustical field using a four-microphone configuration implemented in a previous study (M. W. Budhiantho, Acoustic Velocity Related Distributions dissertation, The University of Texas at Austin, August 1997) has been extended to a seven-microphone configuration in this report. An effort has been made to model acoustical field near the boundaries of an enclosed space (reverberation room). Also 3-D imaging technique of acoustic intensity is also presented in this report.