Positional dependence on localization dominance in the median-sagittal plane

Abstract

Previous experiments by the authors investigated aspects of the precedence effect in both the azimuthal and median-sagittal planes in a virtual acoustic environment. Among the aspects studied was localization dominance; where the location of a lead-lag combination is dominated by the leading source. It was apparent that the virtual presentation was not providing an adequate elevation percept in the median plane, possibly due to the use of nonindividualized head-related transfer functions. Nonetheless, subjects, who were given feedback, were able to use timbral differences in the fused lead-lag pairs to perform the task. The results of similar median plane studies in a free-field anechoic condition are reported on, where location percepts are more robust. Preliminary results show position-dependent biases, where some lead positions (front) show greater amounts of localization dominance over certain lag positions (overhead). Frontal dominance has been shown in previous work in the median plane (Rakerd and Hartmann, personal communication). It is postulated that some positions in the median plane are dominant, and that in a competition paradigm such as localization dominance, the amount of dominance given to the lead would be dependent on the locations of the leading and lagging stimuli. [Work supported by NIH Grant Nos. DC02692 and DC00100.]