Non-visual exploration of geographic maps: does sonification help?

Purpose. This study aims at evaluating the effectiveness of sonification as a mean to provide access to geo-referenced information to users with visual impairments. Method.  Thiry-five participants (10 congenitally blind, 10 with acquired blindness and 15 blindfolded sighted) completed four tasks of progressive difficulty. During each task, participants first explored a sonified map by using either a tablet or a keyboard to move across regions and listened to sounds giving information about the current location. Then the participants were asked to identify, among four tactile maps, the one that crossmodally corresponds to the sonifed map they just explored. Finally, participants answered a self-report questionnaire of understanding and satisfaction. Results.  Participants achieved high accuracy in all of the four tactile map discrimination tasks. No significant performance difference was found neither between subjects that used keyboard or tablet, nor between the three groups of blind and sighted participants. Differences between groups and interfaces were found in the usage strategies. High levels of satisfaction and understanding of the tools and tasks emerged from users' reports.