Near-Field Localization Response Methods.

摘要

Four response methods that allow subjects to indicate perceived locations within one meter of their heads were evaluated experimentally. In the Direct-Location (DL) method, the subject moved a response pointer directly to the perceived target location. In the Large-Head (LH) method, the subject moved the response pointer to the perceived location, relative to a manikin head, that corresponded to the location of the target relative to their own head. The Small-Head (SH) method was similar to LH, except that a half-scale manikin head was used and the subjects were asked to scale down their response distances by a factor of two. In the Verbal Report (VR) response, subjects verbally indicated the spherical coordinates of the target location. Measurements with a visual target indicated that DL was relatively unbiased and considerably more accurate than the other three methods. The three indirect methods, relatively LH, SH, and VR, were all roughly equivalent in performance. Correcting for bias improved accuracy in the LH, SH, and VR response, but even with bias correction these methods were inferior to the uncorrected DL response. When the visual target was replaced with an acoustic stimulus, the errors in the DL response were approximately doubled. The errors in the acoustic experiment were, however, roughly equivalent in the front and rear hemispheres, despite the expected difficulties of reaching behind the body and outside the visual field. The results suggest that DL is the most appropriate response method for near-field auditory localization experiments.