Wierd noise at speed

Hey peeps, the last couple days my car has started making a fluttering/ squeeling from the pasenger side area. I first figured this was a blown speaker. But today I had my stereo off and it was still making it. It only does it sometimes too, just on and off. Random. Its gets louder and more comman at higher speeds too. Think I have an air leak? I'm stumped, I quick glanced at the door gasket and it looks alright. any ideas??