There is a recent human study [Perrott et al.,1993, JASA 93:2134-2138] that shows that the auditory modality is as good, if not better than the visual in determining the relative spatial directions of stimuli presented sequentially. Other work by this group shows that the auditory modality is superior to the visual in redirecting the center of gaze. John Olsen NIMH Lab. Neurophysiology