Virtual sound source construction based on wave field synthesis using multiple parametric array loudspeakers

Due to the development in three-dimensional (3D) vision technology, the study of 3D sound field reproduction has recently gained attention. We have previously proposed a virtual sound source (VSS) construction method using multiple parametric array loudspeakers (PALs) which have a shaper directivity. In previous method, we construct a linear PAL array by arranging multiple PALs at equally spaced positions in straight line, and the emitting angle of each PAL can be mechanically controlled by the pan-tilt unit. By using this linear PAL array, we can form a focal point of the emitted sound from each PAL at any position and construct a VSS at the focal point in the air. However, the previous method requires many pan-tilt units which are much expensive. Thus, in this paper, we propose the VSS construction method based on wave field synthesis (WFS) using a linear PAL array. In the proposed method, we derive driving functions when directional sound sources are used as secondary sources and reproduce the VSS. By using a WFS, the proposed method can construct a VSS at any point with fixing placement angles of PALs in the front direction. Finally, we confirmed the effectiveness of the proposed method through evaluation experiments.