Are any of you doing Daniel's Oneirophone mp3s? If so, how high do you set the volume? I'm not sure if I should set it to a volume where it sounds like RL, aka like I'm actually next to the ocean or birds are actually chirping in front of my window, or just loud enough that I can barely hear it, which might be enough to let it filter into my subconsciousness. So far, the cue sound has not made it into my dreams, or at least I don't remember it.
Try tinkering with the volume until you find a sweet spot. Generally your mind is far more sensitive to sound during the night, so assume what sounds quiet during the day will sound like a fog-horn during the night!
By now, I suspect that I don't notice the cue sound in my sleep for much the same reason that I never do reality checks even if I notice something is off... I might notice the triggers on some level, but my reaction is lacking.