Recording sound from a video-only device that has been covered, with no hardware modifications would be a really really neat trick! Using Van Eck phreaking against all sorts of hardware is fascinating to me. FM radio broadcast from how RAM gets accessed and things like that. Maybe noise in the camera sensor can be used to pick up noise from the microphone on the motherboard (which is where the microphone is on Apple Silicon devices). I'm not going to say it's impossible, but it seems highly unlikely given everything else in play.