Investigations on control and perception of virtual distance using loudspeakers

The proposed system enables the control of sound sources in a large auditorium both in direction and distance. Reproduction of 3D sound fields over loudspeakers whereas distance coding is taken into account is a rather difficult goal. Because different simple and complex properties of a sound event contribute to the perception of distance. Similar to the perception of pitch, the perception of distance is bounded in both directions. Small deviations concerning far and very short distances can hardly be distinguished. Furthermore, caused be the associated memory, the impression of distance is always biased and relative. Therefore, similair to the visual sence the auditory sence can be easily confused. To overcome these problemes the reproduced sound field should be identical to the natural one as much as possible. As will be shown below the presented approach is based on the reconstruction of the wavefront curvature in a defined listening area in order to perceive the desired distance. The subject of this paper is to find out and validate objective description which correlates with subjective perception. Based on this correlation, optimization criterias can be evaluated to maximize the reconstruction performance in order to control the desired spatial auditory stimuli of perception.