Why does my Audi A6 constantly make a high-pitched whining noise?

I've noticed that my Audi A6 makes a constant high-pitched whining noise while driving, especially at higher speeds. It's not very loud, but it's definitely noticeable. Any ideas on what could be causing this?

This could be caused by a worn or loose drive belt. It's important to have this checked and replaced if necessary, as a failing drive belt can cause further damage to your car's engine.

The noise could also be coming from a faulty wheel bearing. It's best to have a mechanic inspect and replace the bearing if needed, as it can cause issues with wheel alignment and stability.