It's actually a very quiet filter.. It makes a small hum that you can't even hear unless you put your ear next to it. I hardly get a peep out of mine besides the occasional water rushing sound it'll do, which is still quiet.
yeah forgot about that, every 24hrs it shuts off for about 2 mins. of to get all the air out and it makes a lil noise when it starts back up, but still extremely quiet.