ProForm Smart 2000 Treadmill

This is a sound my treadmill makes with or without me on it, when the speed goes up past 6.5 mph.

When I'm running on it it's more subdued as a noise. I thought it was part of the videos with microphone feedback for a few runs until I did a run without sound. It only occurs at 6.5 mph or higher.

Combined with the creaking noise from the other two videos you can imagine my experience with this Proform Smart 2000 treadmill hasn't been the best. It's made some sort of noise since the day I assembled it five months ago.

Customer service just keeps telling me a technician will be in contact with me.

If anyone knows what else I can do to fix this I'd greatly appreciate it!

UPDATE: I have lubed the belt and it did not help.

UPDATE 2: I loosened the belt 1/4 turn on each side and it dramatically reduced the noise. Given that I've never tightened the belt before, I'm not sure how it magically got tighter after 200 miles.