I get these, but for me it’s not real-time noise. It’s noises and voices I heard throughout the day. It feels like they’re being replayed from a tape recorder right as I fall asleep.
It’s sort of like when you play a lot of Tetris and you can’t stop seeing the falling bricks as you fall asleep.
Never noticed this from any single-threaded activity. But once I played two games in parallel for a few hours (two instances of wow) that had a direct impact on trying to fall asleep. The task-switching tried to check my other self, but there was no other instance to switch to.