2010 Yukon 1500. Strange sounds in motor compartment

[ky wonder]

Was riding with my daughter last night and heard strange sounds coming from under the hood.
She drives a 2010 Yukonxl 1500 with the 5.3, with 204000 miles

It sounded like a twin rotor helicopter was hovering overhead
Not a metal sound but more of a air sound.

I have been driving gm vehicles with the 5.3 for over 20 years
I've never heard this sound before. Have a 2000 silverado model with 212000, a 2008 sierra 1500 with 237000, on it and a 2018 Sierra with 22000, so I am stumped