Relation between acoustic measurements and the perceived diffuseness of a synthesised sound field

Abstract

This paper describes an investigation of different objective metrics for predicting the perceived diffuseness of reproduced sound and why common metrics, such as Interaural Cross-Correlation Coefficient (IACC), sound pressure level uniformity, and the diffuseness calculation used in Directional Audio Coding (DirAC), may be less appropriate for analysing the perceived diffuseness of a reproduced field than they are for architectural acoustics applications. A listening test was conducted to elicit the perceived diffuseness of sound fields of uncorrelated pink noise signals replayed over 19 different loudspeaker arrangements. Listeners rated how diffuse they perceived each stimulus. A range of different measurements of the sound field were then compared to the subjective test results. The data show that objective metrics do not always correlate well with the perceived diffuseness, especially for specific loudspeaker arrangements. Possible explanations of these results are discussed