Discovering a physical parameter associated with a near-field sound control: comparing HRTFs of nine loudspeakers in a non-anechoic room

摘要

Previously, the authors proposed a novel method of near-field sound control using an electrostatic loudspeaker radiates planar wave from above the listening position. The method was based on a pseudo inside-head-localization (IHL) phenomenon similar to headphone listening experience, which generates a near-field sound image. To search for a physical parameter associated with this near-field image rendered through the electrostatic loudspeaker, the authors measured the head-related transfer function (HRTF) with eight conventional loudspeakers and compared them with the HRTF of the electrostatic loudspeaker. The HRTFs were measured at three distances (0.75, 1, and 2 m) in a non-anechoic listening room. The results were similar to the previous HRTF measurements at an anechoic room and numerical simulations, showing that the variances of group delays were associated with the distances. Moreover, the variance of electrostatic loudspeaker measured at 2 m was similar to the variance in conventional loudspeaker at 0.75 m, suggesting a reason for near-field sound images from the electrostatic loudspeaker in a reverberant room.