Paving the way for social touch sonification: behavioral studies and applications in virtual reality
Résumé
With the increase of social isolation and distant communication, it appears timely to allow distant socio-affective interactions. To do so, we developed a methodology combining the use of a novel sonification technique that considers skin as a singular sonic texture and prototypical social touch gestures. Three studies explored the feasibility of this technique, its core components, and its potential applications in virtual reality. In the first study, the vibratory signals from prototypical skin-to-skin touches were recorded with a piezoelectric transducer, allowing their conversion into sounds. The resulting sonified signals were presented to participants who were able to accurately categorize both the different gestures (stroking, rubbing, tapping, hitting) and their underlying emotional intentions (love, empathy, joy, impatience, fear, anger). The second study investigated the respective roles of rhythm and textural properties on participants’ abilities to recognize social touch through sounds. The same tactile gestures as in the first study were reproduced in two different surface conditions: skin-on-skin and object-on-object. The results revealed that the dynamics of the surface involved in the touch are crucial, and that skin-on-skin interactions bear information that sets them apart from object-on-object movements. The third study was conducted with the platform of virtual agents Greta, which allows simulating 3D touch gestures between the user and the virtual agent. Participants performed a virtual reality game during which they received socio-affective touch from the agent, or not. We then quantitatively investigated participants’ perception of the virtual agent depending on their tactile behavior and the emotional intentions conveyed this way. These results pave the way for allowing social touch at a distance, through multisensory channels, with both humans and virtual agents.