It was called Acousmatic

Daniel Teruggi (composer, director of GRM 1997-2017) to Patrick K.-H. (composer, Floating Sound Gallery) on Acousmatic, its meanings, origins and history: hearing phenomena, cinema for the ears, Pierre Schaeffer, Luc Ferrari and Francois Bayle, "music concrete" vs. "music abstract", "sound object" and "musical object", active listening. GRM (Paris), June 2018. Camera - Anastasia Blur. https://www.acousmonium.info/ https://inagrm.com/ TG https://t.me/acousmonium