Would noise really be an issue with zombies though? They attack anything that moves that's not one of them, and can smell even the faintest hint of non-coagulated blood even if you barely nick yourself on an exposed nail, and in some respects are hypersensitive to changes in light like from a flashlight.
Personally I also think it'd be useless if you get surrounded should you step on loose gravel or some broken glass or whatever, because even the fastest Archers can't put out one hundred arrows in the span of 20 seconds that it would take for the zombies to close in and suck your brain out of your cranial cavity like a frapuccino...
=P
Silence is important. You can sneak your way past zombies.
Unfortunately, a crossbow is a poor choice. One with any degree of power is large and cumbersome and noisy to carry even if it's quiet to fire. Also, past a certain point, power and accuracy are inversely related with bow-weapons.
But most importantly, just where are you going to find ammunition?
[Edited by Dhampy, 8/28/2010 8:23:07 PM]