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datahoarder
Who are we?
We are digital librarians. Among us are represented the various reasons to keep data -- legal requirements, competitive requirements, uncertainty of permanence of cloud services, distaste for transmitting your data externally (e.g. government or corporate espionage), cultural and familial archivists, internet collapse preppers, and people who do it themselves so they're sure it's done right. Everyone has their reasons for curating the data they have decided to keep (either forever or For A Damn Long Time). Along the way we have sought out like-minded individuals to exchange strategies, war stories, and cautionary tales of failures.
We are one. We are legion. And we're trying really hard not to forget.
-- 5-4-3-2-1-bang from this thread
I can't speak to what you're looking for specifically, however I can give you an idea of the level and type of noise you could expect.
With a local server I built with 3 standard 8TB HDDs, the "noisiest" part of the whole computer is the fans itself - it's very quiet compared to say, a fanned air purifier on full or maybe even half power. I've never actually heard my hard drives from any of the computers I've built in the last 6-8 years, and I'm usually right by them. If I listen very closely I may hear some ticking/spinning if they happen to be ramped up.
So under load, there may be a chance of hearing some of the spinning disks in a quiet room, however I haven't actively heard an HDD since 2012 - though the size you're going for could be different as you mentioned. I can't speak for the 18tb sizes. As for the smaller external HDD's, I have 3 6TB ones running in tandem and it's pretty much the same, I've heard them ramp up slightly but it's nearly silent even under load it's more of a gentle hum. If there were any noise sources like music it would be unnoticeable. But again, the size may play a factor.
You mentioned it's right by your bed but would your active hours align with the backups? I.e. if you run them overnight from 2a to 8a, you'd already be asleep for the backup. If it's noise that prevents you from sleeping that may help.