Sound field reproduction and sharing system based on the boundary surface control principle

In this paper, we introduce a newly developed sound-field-reproducing and -sharing system. The system consists of an 80-channel fullerene-shaped microphone array and a 96-channel loudspeaker array mounted in an enclosure called a sound cask, so named because of its shape. The cask has two functions. First, it functions as a precise sound field reproduction system. The sound signals acquired from a microphone array in any sound field can be reproduced in the sound cask after passing through filters that modify the amplitude and phase on the basis of the boundary surface control principle. The large number of loudspeakers result in the precise orientation and depth of sound images. Second, it functions as a platform for a sound-field-sharing system. Several casks located remotely can appear to exist in the same sound field for subjects inside a cask. In addition, the cask is large enough for one to be able to play a musical instrument inside it. The musical sound or voices produced by subjects can be shared by subjects in a distant cask after convoluting the impulse responses of the original sound field. The concept of the system is explained in detail.