Place it at the very end of a short argument edit, after the back-and-forth has peaked, and let it close the scene. Put a Vine Boom hit just before it for a final beat, then follow with a Dun Dun Dun sting to underline that the debate is finished.
À propos de ce son
This is a short spoken line, just over a second and a half long, delivered in a flat, resigned voice that sounds like someone giving up on an argument mid-sentence. It lands with a dry, dismissive humour, the kind of weary shrug that ends a pointless debate without raising your voice, and it works because the delivery feels tired rather than angry.