Multimodal exploration of virtual objects with a spatialized anchor sound

A multimodal interactive system for audio-haptic integration is presented in this paper. Preliminary subjective tests with a virtual reality setup were conducted with the goal of interpreting cognitive mechanisms and improving performances in orientation & mobility protocols for visually impaired subjects, where spatial representations need to be developed using residual sensory channels. An object recognition experiment was performed in order to investigate the contribution of dynamic spatial audio cues, in the form of an anchor sound delivered through headphones using customized Head-Related Transfer Functions (HRTFs), integrated with haptic feedback. This setup was employed in the active exploration of simplied virtual environments in which the spatialized anchor sound was placed at the center of a virtual object. Overall results on recognition time reveal a relationship between anchor position and object shape. Moreover, a qualitative analysis of the exploration paths highlights behavioral changes between unimodal and multimodal conditions.