Not sure if anybody out there can help....?

My Audi has just started wining from the front engine area where the PS, Air Con etc pulley belt drives.

Its not the PS pump as this has been checked, nor the Air Con as the noise never changes regardless whether this is on or off.

The Cam Belt was changed 2 years ago.

Reading hundreds of forums I am thinking tensioners, maybe...... not sure what else the belt drives?

The noise is continuous from start and the pitch does not change during driving and sounds like a high pitch turbo whine.

The car still drives very well except for the noise .