Auralization of Measured Room Transitions in Virtual Reality

To auralize a room's acoustics in six degrees-of-freedom 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 auralization 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, although direct sound, early reflections, 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 equalized. The proposed method is first evaluated numerically, which demonstrates its improvements over a basic linear interpolation. A listening test is then conducted in six degrees-of-freedom VR, to assess the density of SRIR measurements needed in order to plausibly auralize 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.