Measurement of 3D sound field formed by orthogonal three lines speaker array

This paper describes actual measurement of 3D sound field which is formed by multiple lines speaker array. In order to realize a novel hands-free sound interface for human-machine systems, the authors are studying multiple lines speaker array. A technique to transmit sound towards a specified direction by speaker array of one straight line is known as beam forming. The authors propose an idea that two and three orthogonal lines speaker array can form spot-like small area of higher sound pressure level. We conduct simulation of two and three lines speaker array. Simulation results support feasibility of the proposed idea. Based upon the results, the authors construct 32 by 2 lines array and 32 by 3 lines array. And we actually measure 3D distribution of sound pressure level by the constructed speaker arrays. Results of the measurement also support the feasibility of our idea.