으면서 자다

fall asleep doing something

"-(으)면서" (while) plus 자다 "sleep", so: sleeping with something going on. Six of these lines are 들으면서 자다, falling asleep to something playing — I put these in and listen as I fall asleep, falling asleep to the lovely British accents, listening to history ASMR to fall asleep, I sleep to very calm music. Two others use it for other things done while asleep: people can actually sleep while walking, and a joke that you surely wouldn't eat in your sleep.