Application of sound field reproduction system to acoustic welfare engineering - Real time sound field transmission system for parent and child room in a concert hall -

Abstract

This study attempted to implement a real-time sound field reproduction system for a parent-child (PC) room in a concert hall as an example of acoustic welfare engineering. The PC room is typically located at the rear of a hall where visitors with their children can enjoy performances without hesitation, but the sound quality is rarely discussed. This study attempts to improve this situation using a multi-channel reproduction system. Specifically, we implemented a system in which the directional impulse response of the hall measured by a microphone array is convolved in real-time with the sound played and captured separately on stage and reproduced by a loudspeaker array installed in a PC room. The 24-channel system, in which the polar and azimuth angles are both 45 degrees apart, our standard procedure, was found to have a high degree of physical reproducibility. Still, it needed to be more practical considering poor room conditions such as large windows. Therefore, we introduced panning using loudspeakers above and below the window frame instead of using the front loudspeakers. The impulse responses of the original and reproduced sound fields were compared, and it was found that the reproducibility was maintained even with the introduction of the panning.