Sweeking Interior Fan, Me thinks?

Hello,

Lately I have been running my air conditioner with the hot weather and have been turning up the fan speed to keep pace with the heat.

Just latley I noticed a sweeking noise coming from the air vents and when I turn the fan/blower up it sweeks louder. Then another interesting thing is if I turn the steering wheel to the right the fan gets louder yet.

Although, when I turn the fan off there is no sweeking noise what so ever.

Does anyone have an idea on how I can fix this problem?

Any help would be appreciated.

Thanks.