Siilence!

I was reading through Drexel''s skimmer hunt and do plan on a skimmer for future builds. After going skimmerless and fanless lights, I really enjoy the silence and subtle sound of water movement. For you gearheads, what's the quietest skimmer you've not heard? From various literature, nyos has a favorable mention however I'm guessing it's acrylic thickness and pump quality that truly determines sound output.