I sleep about 100 yards away from the setup.   Usually have a fan running in the bedroom.  During the season I have to crack open the window, turn the bedroom fan off so I can make sure to hear the dryer running when Im supposedly sleeping.   We had Kan-sun dryers before with the fan inside, but those things would screem!

I think new design on the fan blades is what keeps it quiet.   Just a steady hum.