Virtually zooming-in with sensory substitution for blind users

When perceiving a scene visually we constantly move our eyes and focus on particular details, which we integrate into a coherent percept. Can blind individuals integrate visual information this way? Can they even conceptualize zooming-in on sub-parts of visual images? We explore this question virtually using the EyeMusic Sensory Substitution Device (SSD). SSDs transfer information usually received by one sense via another, here `seeing´ with sound. This question is especially important for SSD users since SSDs typically down-sample the visual stimuli into low-resolution images in which zooming-in to sub-parts could significantly improve users´ perception. Five blind participants used the EyeMusic with a zoom-mechanism in a virtual environment to identify cartoon figures. Using a touchscreen they could zoom into different parts of the image, identify individual facial features and integrate them into a full facial representation. These findings show that indeed such integration of visual information is possible even for users who are blind from birth and demonstrates the approach´s potential for practical visual rehabilitation.