It’s possible that these lessons may have a subconscious effect, if you listen while sleeping, but they are meant to be engaged with while you are awake and curious. If you find you fall asleep whenever you do one of these exercises, there are two possible explanations. One, there wasn’t anything held in that space. No old trauma stored in the area you are paying attention to, and so this exercise was just deeply relaxing. Two, there is a LOT held in that space and your body chose to check out, rather than engage with it. If this area of your body is not generally tense, and you are able to feel it with sensitivity, then it is probably the former. If this area of your body is tight, painful, or numb, then it’s probably the latter.