It depends on how fast they are turning honestly. Fan noise is a funny thing because there are so many variables involved. First things first........a general rule is: The smaller the fan, the more noise it will make. If we are assuming that the fans are automatically controlled and not under a heavy load, a larger diameter fan will produce less noise than a smaller fan. To cool the card adequately, the single fan on the 580 will have to run faster and it will probably produce a good amount of noise. The dual fan setup(which look to be larger fans) won't have to work as hard as the single, smaller fan and even though there are 2 fans, they shouldn't produce as much perceived noise as the single fan. That is all just me guessing of course, and assuming quite a bit.
Also, those cards have 2 distinct methods of cooling. The dual fan cooler has fans on a heatsink which will expel the air inside the case, while the single 580 fan will blow hot air out the back of the case.