Hey all, long time reader, first time poster

When I am at part throttle and accelerating...maybe .1 to .3 bar...I get this long groaning air sound from the driver's side of the engine compartment. The only thing I can compare it to is if you blew air over the opening of a milk jug or 2 liter bottle. I suspected it was the DV's because the car has over 90k on it and they looked original, so I replaced them with 710's and also got a silicon F-hose. After doing that though, the noise is still there. I can't figure it out. After extensive reading I found that there are several check valves in and around that area, but when I boost leak test, I get no leaks.

I am boost leak testing from the turbo inlets. I block off one side and pressurize from the other. Holds solid air

I also replaced the fuel vent valve at the front of the car because I read that the howling sound could have been attributed to that. No luck.

Any ideas or thoughts?