Abstract
The purpose of this study was to map, for a 5-loudspeaker surround system, perceptual dimensions of preference and of audible differences between stimuli, using stimuli that have been created to vary physical aspects of signals that are theorized to influence localization-quality and spaciousness. 'Localization Quality' was defined as the value of re; the vector length in an equation describing summing localization. Spaciousness is varied by manipulating the playback material to change the arrival direction of the late (post-80 ms.) portion of the reverberation. In a scaled pair-comparison experiment subjects were asked to scale the magnitude of the audible difference between each pair of stimuli, and to judge which was preferred. 7 stimuli were presented in every possible pair, each stimulus was created to have one of three values of the localization parameter and one of three categories of arrival direction for the reverberation. The author has contributed to the understanding of the perceptual structure of sound quality for reproduced sound. Descriptors of auditory attributes for natural hearing were elicited, and these were useful for the evaluation of multi-channel surround sound audio. Seven rating scales were created which can be used to distinguish between stimuli, thus providing an indication of the ways stimuli are perceived to be different. Multi-dimensional Scaling (MDS) was applied to listener ratings of difference between stimuli and showed that the stimuli were discriminable on two perceptual dimensions. Multi-dimensional Scaling was used to perform a weighted unfolding analysis of listener ratings of preference, and this created a map that reveals the relative preference for each of the stimuli for each of the subjects, the preference for each of the stimuli for the group as a whole, and how subjects differ in the weighting each applies to the revealed preference-map dimensions.