Abstract
Spatial Audio for Augmented and Extended Reality (AR/XR) is still limited in its suitability for everyday use due to the perceptual and computational demands of such applications. A number of recent studies have highlighted the potential of simplified room acoustic modelling and its perceptual optimisation for making AR/XR applications more accessible with affordable, mobile hardware. This paper presents a perceptual evaluation of real-time acoustic modelling based on feedback delay networks (FDN), scattering delay networks (SDN), and a hybrid of the image source method (ISM) combined with FDN. The acoustics were modelled using a shoebox-approximation of the original room's geometry, two different approximations of the original loudspeaker directivity and generic HRTFs. We chose a flipped loudspeaker scenario as a critical test case. In the listening experiment, we assessed the Audiovisual Plausibility, Externalisation and Naturalness of the modelled sound fields. The SDN implementation with the subcardioid directivity was perceived similarly external and audiovisually plausible as the measured reference. The hybrid ISM-FDN method and the SDN, both with the directivity of a different loudspeaker, were perceived as natural as the reference. The tested FDN cases exhibit significantly lower ratings than the measurement for the three attributes. The chosen simplifications were not perceptually sufficient in the tested scenario, matching some attributes only. More research on efficient perceptual matching of modelled room acoustics for AR/XR is needed.