Six-Degrees-of-Freedom Parametric Spatial Audio Based on One Monaural Room Impulse Response

Parametric spatial audio rendering is a popular approach for low computing capacity applications, such as augmented reality systems. However most methods rely on spatial room impulse responses (SRIR) for sound field rendering with 3 degrees of freedom (DoF), i.e., for arbitrary head orientations of the listener, and often require multiple SRIRs for 6-DoF rendering, i.e., when additionally considering listener translations. This paper presents a method for parametric spatial audio rendering with 6 DoF based on one monaural room impulse response (RIR). The scalable and perceptually motivated encoding results in a parametric description of the spatial sound field for any listener's head orientation or position in space. These parameters form the basis for the binaural room impulse responses (BRIR) synthesis algorithm presented in this paper. The physical evaluation revealed good performance, with differences to reference measurements at most tested positions in a room below the just-noticeable differences of various acoustic parameters. The paper further describes the implementation of a 6-DoF realtime virtual acoustic environment (VAE) using the synthesized BRIRs. A pilot study assessing the plausibility of the 6-DoF VAE showed that the system can provide a plausible binaural reproduction, but it also revealed challenges of 6-DoF rendering requiring further research.