Application of simple visualization system for analysing direction of sound sources by 3D microphones

We have developed a simple visualization system of sound source direction using a 3D microphone and the applicability of the system was verified in an anechoic room and in a real environment. The 3D microphone consists of four microphones and provides information on the direction of arrival of sound that cannot be obtained with a single microphone. By superimposing the 360-degree image taken by the spherical camera and the analysis results, it is possible to clearly visualize the direction of arrival of sound at each measurement location. In the anechoic room, the direction of the sound source can be accurately estimated in the case of single sound source. In the case of two or three sound sources, the direction of the sound source can be estimated accurately if there is a remarkable difference in the frequency characteristics of the sound sources. In a corridor of the 4th floor building, the traffic noises from the front road and the reflection from the surrounding wall can be estimated.