The master bedroom on the first floor is situated over the basement that houses the oil burner (System 2000) which has a stack with an exhaust fan which is mounted right up against the concrete wall. When the burner goes on, a sensor turns on the exhaust fan and the exhaust is expelled through the wall to the outside of the house. The sound from both the burner or the fan or both at the same time resonates into the bedroom and it sounds like you are inside an airplane. I have put sound damping R15 insulation on the ceiling in the basement, but this did little to dampen the noise. What other remedies are there?