What is the absolute quietest hang-on skimmer?

[nlreefguy]

And how quiet is it? i.e. is it louder than your fans, for instance? or your return/closed loop pump? Or other pieces of equipment in your system? Sorry, if that's a stupid question.... you might all be thinking "of course it's louder than a fan... duh!?!"

Quiet in my living room is really important to me - it's also where I have my turntable set up and listen to all my music.