I have a question, again!

car: audi a4 b5, v6 30 valves..

My engine sounds strange.. I would describe the sound.. hmmm, it's like a supercharger.. "wiiiiiiiinnnggg" the sound follows rpm.. and even at idle...

No i do not here this in the speakers.. its not "parasit" (don't know how you name this in english sorry)

It really is the engine that produce thats sound and its kind of loud.. I think it could be the alternator bearing.. but not sure.. Someone understand what i'm talking about? if so, do you have an idea what it could be? Is it a "frequent" problem on the v6 2.8 ?

again, sorry for my bad english [X(]

thanks !

Max