remembering that there's something a bit dodgy about DiRT 2, I'm not that inclined to trust it. On top of that the game runs very well so there isn't typically a noticeable difference anyway.
Far Cry 2 is also so old that you can run it maxed out at 2560 off a single 5850 with no lag, so that's not especially valid either.
I tend only to see Left 4 Dead tested at stupid AA levels (12x or higher) where the GTX cards do take a lead.
Unigine I'm ignoring because it's effectively synthetic.
There are plenty of games not listed here that give nvidia an advantage, but there are also plenty where there isn't bias, and off the bacm of the results there, the 470 is still very much inferior to the 5870.
I use closed headphones, I know what they can achieve. While they are not the best at noise reduction because they aren't expensive, they do a good job of blocking out background noise, but the sort of noise a fan of the type used in graphics cards like the GTX470 and HD5870 makes at high speed, is going to go through them, and still annoy you.
There isn't dispute that the 470 and HD5850 are on evens, that doesn't say they have to perform identically overall, it just means they have to be so close that they're effectively identical, i.e. a gap of 5% on average or less, which is certainly the relationship I see all over the web.