Acoustic source localization using phase difference spectrum images

Abstract

The localization of a single acoustic source on the horizontal plane using phase difference spectrum images is discussed. The azimuth for source is identified from the general linear relationship, which is extracted from the measured phase difference spectrum after filtering. The phase difference spectrum is introduced as the quasi-stationary cross-spectral phase between the sound signals detected simultaneously by two sensors. Acoustic source localization in an anechoic chamber having a metal base plate using two types of sound signals, white noise and voice, indicated that the phase difference spectrum was not affected with respect to the sound pressure level but was affected with respect to the azimuth for source. Although the phase difference spectrum measured in a reverberant room had less continuity as a function of frequency, a linear distribution of the images obtained from the data (dots) was observed on the frequency - phase difference plane. Using the phase difference spectrum images, the azimuths for various sources, which radiated any kind of broadband sound on separated time schedule, were precisely identified even in the reverberant room.