Enriching Graphic Maps to Enable Multimodal Interaction by Blind People

Geographical maps are by their nature inherently inaccessible to blind users since the information is conveyed mainly in a visual way. The attempt to convert all the information to an alternative modality allowing satisfactory exploration by blind people is a very active field of research. Several studies offer interesting solutions currently only available as prototypes. The work described herein investigates multimodality, focusing on the tactile interaction skills of a blind subject. Given the difficulty of rendering all the information available in a generic map in a tactile and/or text (Braille) format, the challenge is to provide additional substantial information content through different means: speech synthesizer, text or sound alerts and vibration events that the user may call as needed. A further challenge of our work is to make a map opportunely modified to "speak" for itself, without using dedicated devices, through web technologies and the possibility of easily developing programs for Android-based mobile devices.