I've seen where a short piece of hose can be used as a sort of stethoscope where one end is placed on the suspected part while the other end is held close to your ear. Maybe that would help narrow it down.
Yep, could be bearing chatter. Most every component has a bearing on each end. A long screwdriver to the ear to act like a stethoscope or possibly the hose would help narrow it down. Or as mentioned remove 1 belt at a time. It's hard to tell from a video it's location. Maybe a belt is too tight and causing failure.