Learning non-visual graphical information using a touch-based vibro-audio interface

This paper evaluates an inexpensive and intuitive approach for providing non-visual access to graphic material, called a vibro-audio interface. The system works by allowing users to freely explore graphical information on the touchscreen of a commercially available tablet and synchronously triggering vibration patterns and auditory information whenever an on-screen visual element is touched. Three studies were conducted that assessed legibility and comprehension of the relative relations and global structure of a bar graph (Exp 1), Pattern recognition via a letter identification task (Exp 2), and orientation discrimination of geometric shapes (Exp 3). Performance with the touch-based device was compared to the same tasks performed using standard hardcopy tactile graphics. Results showed similar error performance between modes for all measures, indicating that the vibro-audio interface is a viable multimodal solution for providing access to dynamic visual information and supporting accurate spatial learning and the development of mental representations of graphical material.