Repetition/Memorization and learning?

Yeah, because it's constantly sinking in. I'm not completely sure about the sleep one, but I have heard of people playing audio to brainwash people while they sleep, so I guess it would. Just don't rely on that as your main source of studying. Also, I read in a magazine that when you take a nap (or sleep), it clears out your short term memory and moves all that info to your long term memory. So maybe take quick naps after you study, and that'll help you too! Good luck on your AP test (: