Acoustic feedback canceller for the three-dimensional sound field simulator using a "Sound Cask"

We have developed a three-dimensional sound reproduction system based on the boundary-surface control principle. "Sound Cask" comprises a 96-channel loudspeaker system to reproduce the sound field. It has a space large enough to allow a small musical instrument such as a violin to be played. Using Sound Cask, we aim to construct a three-dimensional sound-field simulator. Furthermore, we also propose a sound-field-sharing system that enables telecommunication as if we were in the same place. However, acoustic feedback occurring in the system owing to the presence of microphones causes an echo and a degradation of simulated reverberation characteristics. In this study, we aim to suppress the acoustic feedback by applying additional control points called "null spaces" at the positions of the microphones.