I live in a relativley noiseless city, because not much lives out here, and in China there aren't always cars going every which way at night. Traffic thins considerably after 10PM and doesn't pick up until 7 or 8 AM. I now consider myself suburban.
Now, as for living in the country, i've lived there before for a matter of a week (where people literally still rode horses around) and i'd say you haven't really experienced silence until you've gone to a similar area. Try turning off your computer, hiding under 3 or 4 blankets and then putting a pillow over your head. That's what it's like. The only thing you can hear is the crickets, and maybe the ocasional clop clop of someone comming home after some late night fire-water rounds (drinking).
I've managed to build a totally fanless system based on the following specs
Via C3 with PAL6035
Fanless ~140 watt powersupply. Well, almost fanless. Like, a fan running on a 1.5 volt DC source.

Just to be on the safe side.
Baracuda 4
Geforce 4 MX 420 (Yes, fanless)
And the Baracuda 4 is by far the loudest thing in the system.

The idle noise would drive you mad in any night time suburban/country situation. Even in the city you could still hear it whir. But it's still miles ahead of a Baracuda 2 (I have one) and I plan to upgrade that machine to a baracuda 5 in the near future. My advice is if you really wanna experience peace and quiet, put together a C3 system with a fanless powersupply and experience the joy of silence. Not until then will you realize how annoying that Delta truly is.