Real-time 3D Ambisonics using Faust, Processing, Pure Data, and OSC
This paper presents several digital signal processing (DSP) tools for the real-time synthesis of a 3D sound pressure field using Ambisonics technologies. The spatialization of monophonic signal or the reconstruction of natural 3D recorded sound pressure fields is considered. The DSP required to generate the loudspeaker signals is implemented using the FAUST programming language. FAUST enables and simplifies the compilation of the developed tools on several architectures and on different DSP tool format. In this paper, a focus is made on the near-field filters implementation which allows for the encoding of spherical waves with distance information. The gain variation with distance is also taken into account. The control of the synthesis can be made by software controllers or hardware controllers, such as joystick, by the mean of P URE DATA and O PEN S OUND C ONTROL (OSC) messages. A visual feedback tool using the P ROCESSING programming language is also presented in the most recent implementation. The aim of this research derives from a larger research project on physically-accurate sound field reproduction for simulators in engineering and industrial applications.