Participatory workshops have been organized within the framework of the ANR project Legos that concerns gesture-sound interactive systems. These workshops addressed both theoretical issues and experimentation with prototypes. The first goal was to stimulate new ideas related to the control of everyday objects using sound feedback, and then, to create and experiment with new sonic augmented objects. The second aim was educational. We investigated how sonic interaction design can be introduced to people without backgrounds in sound and music. We present in this article an overview of three workshops. The first workshop focused on the analysis and the possible sonification of everyday objects. New usage scenarios were obtained and tested. The second workshop focused on sound metaphor, questioning the relationship between sound and gesture. The last one was a workshop organized during a summer school for students. During these workshops, we experimented a cycle of design process: analysis, creation and testing.