Noise levels of CPU coolers

[Destination]

I've a new i7 920 build, currently with the stock cooler, which I am considering replacing, (fully aware I'll have to take the whole thing aparent to fit a backboard but such is life) my query relates to noise.

Under load the stock cooler isn't particularly loud, in fatc my whole system is reasonably quiet. What are the noise levels of the noctura and TRUE like compared to the stock intel cooler? I have been made aware the fenrir blows a tornado at full pelt, so how do the others rate, and in which fan configurations?

TIA

 

[Destination]

Yes I was aware the TRUE is passive, but I would expect a fan to be fitted, are TRUE's usually fitted in push-pull or just one-sided?

With fans fitted how does the true compare to the noctura for noise levels?

 

[Destination]

Thank you both for the replies.