Design of 3D Moving Sound Image with Spherical Parametric Loudspeaker

We have previously proposed the system with parametric loudspeakers for three-dimensional sound field reproduction. It can design sound images on walls, floors and ceilings by reflecting the emitted sound on them. However, it requires multiple parametric loudspeakers for designing multiple sound images. In addition, it hardly designs moving sound images because directivity of the parametric loudspeaker stays constant. We therefore propose the method for the moving sound image with the spherical parametric loudspeaker consisting of ultrasonic transducers arranged on spherical surface. It can design multiple sound images, and steer the location of sound images by switching ultrasonic transducer-board for emitting the sound wave. As a results of the subjective experiment, we confirmed the proposed method can design multiple sound images and the continuous-moving sound image.