My understanding is that the heavy feeling is a sign that you're entering a level of trance which may be deep enough to OBE. From there you may want to try an exiting technique.
It sounds to me like you're in a light trance state, although I usually dont get whistling in my ears in the light trance state. Just try to go with the sound and relax after a bit vibrations should kick in. Try not to even think about the sounds, take it as a natural environment type sound.. once I dropped into a very heavy trance and had pre exit vibrations and it sounded like someone was pounding on my door furiously, I knew this was all in my head but it startled me all the same. Oh well, practice makes perfect :)
Carry on and dont give up, sounds like you're getting to where you need to be.
-Impunity
-I once knew a man from nantucket.....
Was I supposed to have OBE after I heard the loud whistle sounds? rather than having a OBE I get this heavy feeling like something is pushing against my body, any one have any idea's?