I am honestly completely opposite in this regard. Any sort of 'content' will keep me up for hours if it's playing near me. On vacations with friends and family, if others put on a movie to fall asleep to, I'll watch the entire thing. I've tried falling asleep to podcasts - but I have a compulsion to not allow my attention to be diverted from it. If I start dozing off and miss some - I'll go back a few clicks and make sure I'm aware.

That having been said, the white noise of a fan is always lovely to fall asleep to.