Towards an Objective Quality Metric for Interpolated Directional Room Impulse Responses

Abstract

This paper introduces a novel objective quality metric for predicting the impact on Listening Quality (LQ) and Localisation Accuracy (LA) of interpolated Directional Room Impulse Responses (DRIRs). The DRIRs in this paper are First Order Ambisonic (FOA) representations of the RIR. Interpolation is used to synthesise a DRIR at a new listening position using known DRIRs at neighbouring listening positions. The target application is spatial audio synthesis for Virtual Reality (VR) that adapts to the position of the listener. The LQ and LA scores are based on the Pearson’s Correlation Coefficient (PCC), comparing segments of reference and synthesised DRIRs. These scores compare well with results from other representative objective measures of Ambisonic audio quality using DRIRs convolved with sound sources. A benefit of the proposed approach is predicting the impact on spatial audio quality when using interpolated DRIRs.