If you're talking about the drive in my previous HP computer, then it's barely audible, you could just hear when it's reading/writing but it wasn't noticeable.
The new PC is a new build, the drive is loud and very noticeable.
I'll be returning the drive back to eBuyer and getting a Samsung F3 instead.
EDIT: Also to add, the hard drive does also vibrate quite a bit when it's making the noise.