While vision has been shown to play an important role in calibrating the spatial representations of other senses [1-2], numerous recent reports have suggested that individuals deprived of vision are actually able to develop heightened auditory spatial abilities [3-4]. However, most such cases have compared the blind to blindfolded sighted individuals, a procedure that might introduce a strong performance bias in that blind individuals, who have had their whole lives to adapt to this condition, whereas sighted individuals might be put at a severe disadvantage when suddenly being asked to localize sounds without visual input. To address this unknown, we compared the sound localization ability of eight sighted individuals with and without blindfold using a 3D sound presentation device in a hemianechoic chamber. We used a 2x2x2 factorial design, where we compared two vision conditions (blindfold vs. non-blindfold), two sound planes (horizontal vs. vertical) and two pointing methods (finger vs. head). A 2x2x2 repeated measures ANOVA revealed a significant effect of vision (no-blindfold > blindfold; p<0.001) and a significant effect of plane (horizontal > vertical; p<0.001). Moreover, a vision x plane x pointing triple interaction was also significant (p=0.004), and was primarily driven by a significantly poorer performance of head pointing in the horizontal plane when blindfolded, compared to the non-blindfolded condition. This result argues strongly against the use of head pointing methodologies with blindfolded individuals, particularly in the horizontal plane, as it likely introduces a robust bias when comparing them to blind individuals.

Sound localization; visual feedback;blindness