Investigations on the Influence of Combined Inter-Aural Cue Distortions on Overall Audio Quality

TL;DR

This study systematically investigates how combined inter-aural cue distortions affect perceived audio quality, providing guidelines for designing better spatial distortion measures in perceptual audio quality prediction.

Contribution

It introduces a systematic approach to analyze the interaction effects of multiple spatial distortions on perceived audio quality, which was previously not well understood.

Findings

Interaction effects significantly influence perceived quality

Guidelines for designing inter-aural distortion measures

Enhanced understanding of spatial distortion interactions

Abstract

There is a considerable interest in developing algorithms that can predict audio quality of perceptually coded signals to avoid the cost of extensive listening tests during development time. While many established algorithms for predicting the perceived quality of signals with monaural (timbral) distortions are available (PEAQ, POLQA), predicting the quality degradation of stereo and multi-channel spatial signals is still considered a challenge. Audio quality degradation arising from spatial distortions is usually measured in terms of well known inter-aural cue distortion measures such as Inter-aural Level Difference Distortions (ILDD), Inter-aural Time Difference Distortions (ITDD) and Inter-aural Cross Correlation Distortions (IACCD). However, the extent to which their interaction influences the overall audio quality degradation in complex signals as expressed - for example - in a multiple stimuli test is not yet thoroughly studied. We propose a systematic approach that introduces controlled combinations of spatial distortions on a representative set of signals and evaluates their influence on overall perceived quality degradation by analyzing listening test scores over said signals. From this study we derive guidelines for designing meaningful distortion measures that consider inter-aural cue distortion interactions.