I also recall that it sometimes feels like i go through a tunnel on the top of my head as i leave the body, often accompanied by a roaring sound that often scares me awake. This roaring sound can be heard and felt daytime as a humming or background sound in da head. Some people would surely call it tinnitus but i feel it is the doorway to the astral or whatever dimensions are subtler than the physical. There is a Yoga called Nada Yoga. Yoga means union and nada sound. So by listening/puttting attention to this sound it grows in intensity and the world it originates from is unveiled to the conscioussness.
someone called David Gordon has written a meditation practice for this on http://www.spiritsound.com/nadayoga.html
and somone called Frank Perry wrote an article on this
http://www.frankperry.co.uk/nada_yoga.htm
someone called David Gordon has written a meditation practice for this on http://www.spiritsound.com/nadayoga.html
and somone called Frank Perry wrote an article on this
http://www.frankperry.co.uk/nada_yoga.htm