Dell E2211Hb 0-15 brightness: almost totally silent, just the slightest hum can be heard with my ear right next to the vent. 15-100 brightness: a sort of "whirring" sound that gradually increases with greater brightness. It's loudest at 100 brightness, but still very subtle (only audible at a couple...

Acer AL2216W 0-90 brightness: medium-pitched whine, audible at about 10 feet in front of the display 90-95: pitched whine fades 95-100: only remaining sound is a very soft wide-spectrum hum/fuzz, audible at about 2 inches from the front (maybe 12-18 inches from the back) Overall: Good! Almost silen...