Bernhard Leitner’s art communicates directly with those who have ears to hear with. Radical sound experiments, dense fields of sound. Leitner, a trained architect, uses sounds to generate mutable spaces; creates innovative, intimate spaces in which one can physically experience the movements of sound; integrates media-based works of art into his architecture; uses exhibition visitors as resonating bodies and plays with their acoustic brains. Initial drafts for a Soundcube (1969) were followed by decades of TonRaumskulpturen (Sound Space Sculptures) in striking variety. Bernhard Leitner develops his artistic ideas in detailed, fragile drawings that can in part not be implemented until the technical conditions for them have been invented or produced. The present publication is the first to provide direct insight into Leitner’s visionary sketchbooks and notes.