differential noise

I'm trying to diagnose this issue we're having with my wife's 2016 JK Sport 4D (99k miles). It starts as a rumble / gear on gear noise at parking lot speeds. (can be heard in the video) Then approaching highway speeds it's a constant low pitch whine, which is unaffected by accel/decel. It's...

I cant figure out what this sound is coming from the rear differential of my 2010 Rubicon. Any and all advise would be helpful.