Auralization of Measured Room Transitions in Virtual Reality

To auralise a room’s acoustics in six degrees-of-freedom (6DoF) virtual reality (VR), a dense set of spatial room impulse response (SRIR) measurements is required, so interpolating between a sparse set is desirable. This paper studies the auralisation of room transitions by proposing a baseline interpolation method for higher-order Ambisonic SRIRs and evaluating it in VR. The presented method is simple yet applicable to coupled rooms and room transitions. It is based on linear interpolation with RMS compensation, though direct sound, early reflec-tions and late reverberation are processed separately, whereby the input direct sounds are first steered to the relative direction-of-arrival before summation and interpolated early reflections are directionally equalised. The proposed method is first evaluated numerically, which demonstrates its improvements over a basic linear interpolation. A listening test is then conducted in 6DoF VR, to assess the density of SRIR measurements needed in order to plausibly auralise a room transition using the presented interpolation method. The results suggest that, given the tested scenario, a 50 cm to 1 m inter-measurement distance can be perceptually sufficient.