[jpohlman]

Do you hear it when just one window front window is opened or the sunroof (if you have one)?
If so try opening the rear window of the opposite side about 3", if it goes away what you're describing is referred to as "helicoptering". Its caused by the interior shape/design of the rear window and isn't Escape specific, the first time I ran into it was on a Kia Optima about 7 years ago.

 

[jpohlman]

Maybe a bad belt in one of the tires?

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[jpohlman]

bottom skirts?
Maybe one has a missing or loose missing push rivet?

 

[jpohlman]

Techs have a nasty habit of tightening those down with a cordless drill and stripping out the plastic nut that snaps into the frame.
Anytime mine hits the shop for anything I always check it afterwards and look for any that are stripped or missing screws.

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