even the quietest chainlines make a little noise-- unless you ride 3/32.
when you watch the pros at the velodrome, you can hear the same chainline noise on their rides as you hear on yours. keep in mind that these guys ride stuff that's designed to work together. if their stuff has noise, yours will too.

3/32, however, especially with a nicer road chain, sounds remarkably silent when your chainline is right.
That said, i hapily ride 1/8 njs stuff. my chainline is is on, so it's quiet enough (and looks hot).

As a rule of thumb, when riding outside by yourself at night or early AM when it's really quiet, your chain's sounds should get lost in the sounds of the rest of your bike (tires on ground, carbon fork resonating).
On the other hand, if you hear your chain more than everything else, it's probably too noisy. give it a little slack or inspect your chainline.