Perception and Evaluation of Audio
The sweet area in which listeners perceive a plausible image of virtual sound sources is known to increase with the Ambisonic rendering order, and typically also with the radius of the loudspeaker layout. Partly, this knowledge stems from experiments using a rectangular loudspeaker layout, partly from experiments with a circular layout. This bears the question: Does the geometry (circle, square, wide or long rectangle layout) affect the sweet area shape and size? Our paper presents comparative listening experiments using different geometries to render a frontal sound through an Ambisonic widening/diffuseness effect. Although theory would assume the circular geometry as its ideal, a wide rectangular geometry tends to yield slightly more favorable properties.