Do all fans make bearing noise?

[Boxfreshchris]

Recently built a new system in a Lian Li case, so its's got their stock 140mm fans installed, and they make an annoying whirling sound which I assume if their bearing. Don't get me wrong, it's not disastrous, but do the more expensive makes, say Noctua, are they silent?

 

[Boxfreshchris]

I'm happy with the "whooshing" noises I get from most fans, it's the metallic grinding type sound that I dislike. The Arctic fans on my AIO make no bearing noise at all.

I've actually got a spare 140mm Noctua fan from a previous server build, I might drop that on and see if I can hear a difference.