Is it a high pitched noise? I had them test everything, even a dollar bill. Nothing worked until they found foam missing around the pin on the door handle. It always sounded like my window was slightly cracked open, and noticed additional noise as well when the fan blew on high. Once they put the foam in, wind stopped getting into the door frame and the sound has since disappeared. I know a lot of people are saying it is the frame or insulation, but in my case it was the foam on the pin of door handle.