I honestly don't hear them at all.... Might be because they are drown out by the Ultra Kaze @ the back, lol. BUT.... This case is IMPRESSIVE with noise reduction. It's honestly very quiet even with the Ultra Kaze and the 2 110CFM Slipstreams in the front @ full blast. I am really really impressed. I couldn't fit the intake fan on the floor like I had wanted and left the top slots covered with the insulation which I am sure is helping greatly with the noise.
LOVE THIS CASE! Thanks for the suggestion on the case CocaCola.