Whirring noise from the rear? C30 d4.

[Justin83]

Hello everyone, new here with a problem/question as is usually the case. Veteran forum user tho and fairly good with the spanners.
We picked up a stunning d4 r design in black today, absolutely love it but there's a "but"....
As per title really. I'll do my best at explaining a noise but its tough to diagnose I know. The noise starts around 60 and gets louder with speed... Not related to engine speed. It's not a grinding or high pitched whistle, more of an owl who's had too many e numbers lol... Like blowing across the top of a half full beer bottle 5 times a second. Could this be failing wheel bearing or is it likely a Culprit of the Volvo wind noise I've read about?
Wheel bearings normally grind or drone, I know they can make different noises tho rarely.
Thanks in advance.