They all say they are "quiet". I've tried several brands over the years, although I usually do not use airpumps for the past 3 years. I do have, however, a couple going, and the best way I have found to silence them is to hang them "freely" so they do not rest on any table, counter, stand, etc. Another way, which I used long ago when I used airpumps extensively, is to use a piston pump and run a number of tanks off of it. I kept it in a cabinet and it ran all sorts of things, on 6-20G tanks.