FAVN is an automated performance tracing the blurry boundaries between reality and imagination, sensory perception and hallucination. Evoking notions surrounding late-19th-century psychophysics and the quantification of the senses, in FAVN, we follow Debussy in sonically reincarnating the protagonist of Mallarmé’s 1876 poem “L’après-midi d’un faun.” FAVN uses the question ‘What did I hear?’ as a way to interrogate the constructive cognitive processes that intervene in apparently purely sensory, or indeed sensual, experiences. Using synthetic sound and a computer-generated voice, this work is presented for the first time in the United States on the occasion of the exhibition “Florian Hecker — Resynthesizers.”