I got some monitors around and have got to test two large screens the last days
24" alu imac... to the extent it can be called a monitor. Silent
Dell 2407 (old 24" monitor) whines at times. Especially if the room is warm
Samsung 181T - Dead silent. Cannot hear anything from it.
And I have been testing:
EIZO SX3031W - Gorgeous 30" screen. Very expensive, but for some reason that I cannot explain, they have put 3(!!!) fans in this thing!. I will give them credit. They have done a reasonably good job making the fans silent. There is no change in rotation speed and a somewhat comfortalble sound from them and the noise is of a character that would be fine in a slightly lively office environment, but I turned it off after less than 2 hours on my desk in my home office (which is quite quiet). That was all I could take.
NEC LCD2690WUXi. 25.5" display. Probably the most expensive 25.5 incher you can get of "mainstream" lcd screens and the display is nothings short of fantastic.
I have seen several complaints about buzzing on this screen on older european models, but that is supposedly fixed in newer models. I got a japanese version on my desk now and it does not whine or buzz (actually there is a buzz, but cannot be heard from the frontside of the screen).
It does however produce a very faint hum. I can hear it if I turn off my Antec P180 and only use my imac. This screen basically makes noise around the same frequency as my P180 (which is very quiet), and I cannot really separate the sound from them if both are on.
I would probably not want it if I only had the imac on my desk, but even so the quality of this display is so good I can almost
forgive the faint hum