~ After listening to both videos, I can only guess at what the noise might be. Since the engine was at an idle, I assume that the supercharger is not engaged. I have been told , perhaps mistakenly, that the twin screw impellers turn even without the clutch engaged, albeit slower than if they were "clutch engaged". Those impellers have bearings on both ends. If (guessing here) the bearing on either end is worn for some reason, I imagine, since those impellers inter twine as they turn, that they may be hitting each other causing the noise. That's all I can think of. Good luck with it...
~ Next Guess ?