A Spatial Audio Quality Inventory (SAQI)

The perceptual evaluation of spatial audio systems may be based on singular auditory qualities such as the localization accuracy or the perception of coloration, on overall criteria of perceptual accuracy such as plausibility and authenticity or on detailed catalogues of auditory qualities. However, only the latter will be suited for the perceptual characterization of a simulation's technical shortcomings and allow for its focused improvement. Therefore, a common vocabulary containing all perceptual attributes which are relevant in this context appears desirable. Existing vocabularies for the evaluation of sound field synthesis, spatialization technologies and virtual acoustic environments were often generated ad hoc by authors or were focused on specific perceptual aspects or on specific spatialization techniques only. To overcome limitations with respect to the relevance and completeness of these vocabularies we have developed a Spatial Audio Quality Inventory (SAQI) for the perceptual evaluation of all spatial audio technologies used for the (re)synthesis of acoustic environments. It is a consensus vocabulary comprising 48 verbal descriptors of auditive qualities assumed to be of practical relevance when comparing (re)synthesized sound fields to real or imagined references or amongst each other. The vocabulary was generated by a Focus Group of 21 German speaking experts for virtual acoustics. Five additional experts helped verifying the unambiguity of all descriptors and the related explanations. Moreover, an English translation was generated and verified by eight bilingual experts. This article describes the applied methodology and presents the English version of the final vocabulary.