3D "Sound Spot" Forming by Multi Axis Speaker Array for Environmental Robot

Abstract

This paper describes 3D sound field generation 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 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 arrays. Results of the measurement also support the feasibility of our idea.

Directional Sound for Long-Distance Auditory Warnings From a Highway Construction Work Zone

“…They are designed for applications like exhibits in museums or retail stores which require only a short range of less than 5 meters. This technology uses arrays of ordinary multiple loudspeakers [8,10,16,17], with the signal to loudspeakers delayed by varying amounts to achieve what is popularly known as "beam steering." A steered array, strictly controlling the launch time from each element, causes all elements to act together in concert at the target location whereas at any other location sounds arrive out of step with each other.…”

“…Consider the arrangement of speakers as shown in Figure 21. The equation for calculating the delays in the near field is [10]:…”

Implementation of luggable linear speaker array system and formation of Sound Spot

“…The linear loud (a) Three lines loudspeaker arrays (b) Plane loudspeaker array Fig. 6 Luggable linear loudspeaker arrays system speaker arrays system has given the appropriate amplitude to output sound [5]. Therefore, Z-axis is a beam of high sound pressure compared with X-axis and Y-axis.…”

Simultaneous generation of various shaped Sound Spots with multiple linear speaker arrays

“…The loudspeaker arrays system forms a spot-like small area of high sound pressure level (hereafter called Sound Spot) only at a specific position such as person's heads. The shape of the Sound Spot with two orthogonal axis loudspeaker arrays (64 channel) [2] and the shape of the Sound Spot with three orthogonal axis (96 channel) [3][4] [5] loudspeaker arrays are different respectively. Then, the purpose of this paper is the simultaneous generation of the two or more shape Sound Spot.…”