Yep, these hallucinations and sounds are a good sign that you're in between the real world and the dream state. Quite a few people get freaked out -- though there is nothing to fear. You'll get the hang of it. ^_^ Either way, it's great that you've already had success with inducing sleep paralysis.

As with ADA.... that's incredibly taxing. >.< But it's a solid method to enhance self-awareness in the dream state. No pain, no gain though, right?