A haptic/acoustic application to allow blind the access to spatial information

This paper describes a multi-modal application, based on haptic/acoustic interaction, to allow visually impaired people to access media with high spatial information content, extending the visual and auditory-verbal data with the tactile sensory channel. Haptic interfaces are exploited to enable the use of touch on 3D virtual objects which have a larger and greater flexibility with respect to physical artefacts. The system allows to interact with haptic/acoustic active objects and to select the information that must be shown on the basis of the user requirements. Two different tests, involving the exploration of indoor environment and of complex geographical areas, are presented. Several experiments, with users with different stories and different level of visual disability, have been done. They showed that the haptic/acoustic interaction and the modularity in the information representation help blind people to cope with the serious and challenging task of managing spatial data