Subjective assessment for the number of channel signals to realize sound field based on wavefield synthesis

Abstract

It is very important to study the affect of the number of channel signals in the sound field reproduction technique based on wavefield synthesis. Though there are many studies of objective affect such as wavefront accuracy, there are not as many studies of the subjective affect such as sound field perception. Therefore, the subjective assessment was designed to evaluate the effect of the number of channel signals, which were synthesized by convolving a sound source to room transfer functions of free field, on the directional perception. In the low-reverberation room, a circle loudspeaker array with a radius of 2 m was set on the horizontal plane. The subjects evaluated the directional perception of the sound image reproduced at distances of 3 and 4 m by playing simultaneous channel signals from the loudspeakers set at intervals of 10, 15, 20, 30, and 45 degrees, respectively. As a result, it was subjectively confirmed that 24 channel signals were enough to reproduce the directional perception of 5 degrees accuracy if the control area was the circle of radius 2 m.