I just now had to get some data from a Maxtor 120GB IDE drive, that I filled 100% in 2003 and never touched since. Figured I'd check every byte on it while I was at it (testable data), and not a single thing wrong with it.

All 16TB and larger drives, regardless of model/brand, are noisy. They have up to 10 spinning platters and a large arms/heads assembly that create audible vibrations.

However, the noise is very much dependent on how they are mounted. If they are screwed directly to a metal chassis or metal trays without any cushioning, the noise will resonate throughout the case, making it worse.

Most NAS cabinets should have various methods of dampening sound, but if not, cushioning drives/trays with rubber/silicon bearings can reduce noise significantly.