approx 00:02 of the video it makes this kind of weird looking noise in background...
The noise in my understanding is caused by the background scanning GroundPlane object as the camera pans around. To get rid of this I reduced "Specular" property of the GroundPlane material to 0.00 - that eliminates the glossy sheen that can be seen when viewing it at certain angles. You will have to tweak the GroundPlane material color because it will now appear much darker.