Sound Field Evaluation by using Closely Located Four-point Microphone Method and Mixed Reality Technology
* Presenting author
The closely located four-point microphone method was proposed by Yamasaki in 1989. The method can grasp the spatial and temporal structures of sound reflections by estimating an image source distribution from four measured impulse responses. In recent years, mixed reality (MR) technology has rapidly developed and is now more familiar. Many sensors, display devices, and ICT technologies have been implemented in MR equipment, which enable interaction between real and virtual worlds. And we proposed an MR display system for image sources distributions and directivity patterns of sound reflections, which are obtained by the closely located four-point microphone method. In this paper, we measured impulse responses at few points using closely located four-point microphone and display image source distributions at these points by using the MR display system. The user can view a real room and the data representation at user’s point simultaneously. In addition, the data at user’s position is displayed while the user is moving in the room. Thus, the user can observe the spatial and temporal structures of sound reflections at user’s position while maintaining a relationship between the positional information of the real room and the data and can evaluate whole sound field of the room.