Coupled audiovisual instruments promise media equality by design, but does causal coupling deliver perceptual parity? A practice-based study of the Cellular Au-Tonnetz, where audio and light are parallel projections of one cellular-automaton state. Nine composers worked under visual-only, audio-only and audiovisual conditions, each followed by a replay revealing the withheld medium.Organised Sound 31(3), Cambridge University Press · forthcoming, December 2026