This morning on my way to work I had this weird sound coming from 'inside' my vent. I assume it's the motor. Here's the recording of the sound, because I find it very hard to explain... https://www.vocaroo.com/i/s0H7VkA7lwRD
I tried turning it off / on, AC on/off, faster/slower, other directions but the noise remained the same. It sounds like the noise is coming from the top center, right under the wind shield..
It was very cold this morning, no snow, but could it be possible that ice has gotten inside of the vents and melted which could've caused this noise?
Vehicle: Audi A6 C6 4F (2005)