I have just started to investigate this phenomenon and was wondering if a particular sensation was normal and to be expected. What I have been doing before bed is listen to a 30minute Mp3 for astral projection and also do deep breathing at the same time. I have felt a small vibration which is normal, I have heard a pop in my head, I have had the sense of floating and sinking but the strangest feeling and strongest has been a strange entire body either twisting or rolling feeling. I am always lying on my back when preforming this exercise and the twisting seems to always be clockwise and the rolling is to my right side. Has anyone else experienced this and does anybody know how close to AP or OBE am I??