What is this sound in my engine bay ?
 

Hi all this sound in my engine bay I can't quite describe, trying to figure out if this is normal or if it requires attention. Thanks!

Nothing stands out, but it would help to know what I'm listening for.

The whirring sound
 

The whirring noise is what I'm concerned about

I hear a low sound that sounds like a gas leaf blower. Is that what you're talking about?
If so, the pitch doesn't seem to change when you rev the engine. Could be lots of things. Disconnected vacuum line or broken hose. Auxiliary cooling fan. A/C compressor. SAI pump (should not be running constantly though).
Kind of hard to distinguish car noise from outdoor background noise.
You may have to do some more careful listening under the hood to try to narrow down a location.

Yeah it was my bad taking the video there...they were doing yard work in the background lol I'll try to put up a better vid today

I have an A4 B5 v2.8 30V and mine makes a bit of a whirring noise too. It also makes a very noticeable whirring sound when I turn the steering wheel (power steering). It doesn't sound unhealthy and if you don't notice anything else wrong with the car, I wouldn't stress too much.