Preliminary study on the perception of orientation-changing directional sound sources in rooms

Recently, how to reproduce the direction-dependent sound of musical instruments was investigated using spherical loudspeaker arrays, with the idea to increase naturalness in playback. As an interesting abstraction, such devices are e ectively employed in spatial computer music using adjustable, arti cial directivities (sound beams). When used in a room, this produces interesting sound objects outside the spherical loudspeaker array whenever the sound from wall re ections exceeds the echo threshold of the direct sound in its level. Nevertheless, our understanding of the nature and thresholds of the perceived spatial sound objects is only vague. Therefore, our contribution shows results of an initial investigation of arti cial-directivity sound sources with variable orientation. To simplify repeatability, experiments were done in a semi-anechoic chamber. In the test setup, direct sound and rst-order re ections of a shoebox room arriving at the listener were all simulated using a surrounding fullrange loudspeaker setup by directional mapping to the closest loudspeaker. Hereby algorithmand size-related properties of a particular spherical array prototype as well as the properties of a particular physical room are avoided. The results con rm that the orientation of directional sound sources can be heard, and that it causes localization de ected from the direct path.