silver,

do you have any blood pressure issues? I know with some of my medications that I can get dizzy and pass out if I stand too quickly after taking certain meds. When that happens if I don't pass out I DO hear a loud whooshing noise in my ears and feel as if my brain has been shaken.

I don't think this is what you are describing but it never hurts to brainstorm this and pare down the list of "what-could-it-be?" so you can ask pertinent questions next time you're at the health centre.