They didn't give me an LD since I really struggle to sleep with headphones on. But they did have an effect; I managed to enter sp within 10 minutes which is amazing compared to the normal 20 minutes. They occasionally make my dreams really vivid too. I don't think they would work with listening a few hours before, I think you have to listen whilst falling asleep or just before at least.
You don't have to use binaural beats either, you could always try some B6. Or if you're not happy with taking tablets, you could always try B6 rich foods like apple juice (not a food, derp), peanut butter or cheese.

Hope this helps