I've used books on tape (audible) with a 30 minute sleep timer. I've been falling asleep within minutes. After a week or two of listening to the same 30 seconds

I've used books on tape (audible) with a 30 minute sleep timer. I've been falling asleep within minutes. After a week or two of listening to the same 30 seconds to a minute, I switch books, because I start to literally dread starting these things up. Perhaps the books are just too boring.