The dimensions of perceptual quality of sound source separation

Quality of sound source separation algorithms has traditionally been evaluated based on a set of established quality metrics: target distortion, interference from other sources, artifacts distortion, and a measure of overall separation quality. In our previous work, listening test results were presented where no significant correlation between these quality metrics and perceptual ratings from the listening test could be observed. Following these results, we now attempt to better understand perceptual quality in a sound source separation context. We focus on determining how separation quality is actually defined by listeners and propose the use of a descriptive methodology to reveal its most relevant dimensions. A combination of Free-Choice Profiling and Repertory Grid Technique is used with 10 human listeners in an attempt to verify if the main dimensions of separation quality truly correspond to those established by the quality metrics. The outcomes of this exploration bring light to the development of new methodologies for sound separation quality evaluation, and suggest a two-dimensional perceptual space for quality of sound source separation.