> "Listening radius" is actually a good name for it, thanks. We need new terminology for spatial-harmonic composition
Someone correct me if I'm wrong, but I'd think you'd call that (the not at all overloaded term) "attenuation" or more complete: "distance attenuation". Maybe it helps for further browsing :)
It seems like Wikipedia ( https://en.wikipedia.org/wiki/Attenuation_(disambiguation) ) has it under "Acoustic attenuation" but very physics-focused, not so much about the musicology, psychology or how it is used everywhere in audio.