I just got the Red Sea Prizm Pro Deluxe on Tueday, and I love it. I replaced Amiracle's SL-15 HOB Skimmer/Sump, which broke..too much to repair..and it was extremely loud. Not just the air hose, but the constant gurgling in the pipeline. The TWO pumps that operated it were quite noisy too.
The Prizm is great! The only noise I hear now is a tiny bit of bubbling inside the skimmer. It is completely sealed off, even the air hose has a place to be so that it is silent. My light's fans are louder than entire the skimmer.
It's rated up to 100 gallons too, so it should work great on a 55.
Oh yea, my tank is in my room also. It is at the end of my bed that I sleep with my head at too.