A4 Spider

After about 5 minutes of having the heat on in the car, I get a strange "tweeting", high pitched squealing sound coming from somewhere in the passenger side vicinity. My friend suspected perhaps a leaf was caught a vent or filter. I am wondering if it is something larger. Has any one else had this problem? Also, it doesn't really start until I make a left hand turn and from that point on it is pretty consistent.

Pizzicato

My blower fan does that on occasion,I simply turn it off/on and it disappears

A4 Spider

Unfortunately that does not work in my case. Once the sound starts, it doesn't stop. No matter if I turn the heater off and on. I guess I am destined to have the squeaking A4.