Distance perception in the sound field reproduced by a linear loudspeaker array

Abstract

When a sound field from a virtual sound source is reproduced by a linear loudspeaker array, a listener in the sound field can perceive the distance of the virtual source, as well as its direction. It has been known that the perception of distance is affected by many acoustic parameters, such as the loudness change, direct-to-early reflection energy ratio, and interaural level difference (ILD). Among them, ILD is the dominant cue to perceive distance when the source is located near the lateral side of the listener [Brungart and Rabinowitz, J. Acoust. Soc. Am. 106(3), Sept. 1999]. Nevertheless, ILD of the reproduced sound field are not identical to that of the target sound field, because the loudspeaker array reproducing the sound field has many practical limitations such as spatial aliasing and truncation of array aperture. To identify these artifacts, especially for the virtual source in a close proximity to the listener, a head-scattering model is constructed using a simple rigid sphere. The ILDs at various head locations are then calculated and compared to those of the target sound field. From the observations on ILD change, a driving function is modified to reconstruct ILDs of the target sound field.