A 3D sound-space recording system using spherical microphone array with 252ch microphones

We are developing a system to acquire 3D sound-space information that can transmit accurate sound-space information to a distant place using a microphone array on a human-head-sized solid sphere with numerous microphones on its surface. The system comprises an object with numerous microphones called Symmetrical object with ENchased ZIllion microphones (SENZI). Each recorded signal from spatially distributed multiple microphone is simply weighted and summed to synthesize listner’s binaural signals. These are presented via headphones. Moreover, the weight is changed according to a human’s 3D head movement. Therefore, 3D sound-space information is acquired accurately irrespective of the head movement. The results of the simulation of previous study indicate that 1) the microphones should be arranged densely to avoid the effect of spatial aliasing, 2) the number of controlled directions should be set densely at less than 5◦ intervals to synthesize sound sources from all directions, and 3) the radius of the microphone array should be equal to the size of listener’s head to express the detail of frequency spectrum characteristics of the listener. In this study, we actually designed the system with 252 ch microphones accordingto these results and investigated the accuracy of synthesized 3D sound-space information. The results demonstrated that the developed system can synthesize 3D sound-space with high precision.