Terra(socio)sonica is a mixed-reality interface which realises a sonic soundscape constructed via the movements of communities that inhabit two current landscape realities that constitute the University of Western Australia (UWA) cultural precinct. Through the translation of movement into sound in both the physical and virtual realms, the work explores the notion of unspoken ‘silent dialogues’ under a paradigm of social engagement. Individuals and large clusters of people produce amplified sounds and shadows based on their oscillating movements within a defined social landscape. The work uses real-time motion-tracking technologies with a unique pipeline application to create a mixed-reality soundscape. This audio environment is mediated through interactions between the viewer, the physical environment, and other participants within a hypersurfaced mixed-reality feedback loop. As visitors negotiate a traditional public environment -the entrance and surround to the Somerville Auditorium at UWA- data regarding their movements and interaction with others present is gathered and translated into sonic outputs, both in the physical and virtual environments. In the physical, the output is via stereo speakers installed in the space and in the virtual, a three dimensional representation shadows and echoes sonic and visual traces of the real-time dialogues into UWA’s Second Life Environment.