Multiple Sound Images Reproduction with Parametric Array Loudspeakers and Indirect Electrodynamic Loudspeakers

We have been previously proposed the method to reproduce the 3-D sound image in the air by utilizing parametric array loudspeakers (PALs) which has a sharper directivity. In the previously proposed method, multiple PALs are linearly arranged and it can present the 3-D sound image to listeners at any points in the air. However, the performance is insufficient in using a small number of PALs because the previously proposed method represents the distance perception by utilizing room reflections and reverberations generated with multiple PALs. It is known that human perceive the distance perception to the sound source with the clue of the direct-to-reverberant ratio (DRR). In this paper, we propose multiple sound images reproduction with a small number of PALs and indirect electrodynamic loudspeakers (IELs) which generate reverberations to control the DRR. In the proposed method, we can represent multiple sound images by constructing multiple systems with a small number of PALs. Finally, we confirmed the effectiveness of the proposed method through evaluation experiments.