High Frequency Vibration coming from winsheild area??

[jramsey0008]

I have an '09 F250 King Ranch CC LB that while driving on the highway (~75MPH) into a head wind a terribly loud vibration comes and goes. I haven't been able to pin-point the source but is is something vibrating from the air flow coming over the hood of the truck. If I turn the wipers on, it will stop when the wipers are at top (reached max stroke) but picks back up when they go down. I don't know if it is coming from around the wiper / vent area or more above the wind-shield around the running lights / sirius satellite antennae. It is so loud it'll drown out the radio and you can't carry on a conversation in the truck. THis only happens while on the interstate and into a headwind / quartering cross wind on the open high way. I can hit 75MPH where there is no wind and never have the problem.

Anyone else know of this or experienced same thing?
Thanks