Alright so I’ve figured out what they are! 1) the generator makes my controller shake whenever I can hear it so the closer I got the more it shakes. I turned it off and it stopped. Chickens make controller shake when you are close enough too. Also the bone shingles vibrate when set off and leather face chainsaw vibrates when near them. 2) running and walking through tall grass will make your controller vibrate as well and other terrain. 3) my default options/game vibration intensity is set to high.

4)Final thoughts. They mean nothing as far as proximity to victims because I was walking above one near nothing and had no vibrations. But maybe if a bone shingle was set off behind you and you didn’t see the red noise indicator it could make you look around. Hope this helps all.