Whistling noise in cabin when fresh air is on

Long time user of this site, first time logging in and posting.
My 06 prerunner makes a whistling noise when the vents are pulling in fresh air, and it goes away when recirc is on. Like the fresh air creates a pressure imbalance and it is pushing air out of the cabin through any little crack it can find, creating the loud whistling. I searched but couldn't find this in a thread. Anyone else with this problem or can point me to a fix?

 

Sounds like you have an air leak somewhere, have you checked if you can hear it on the outside?

 

Check your cabin filter to be sure it's seated properly