Where I grew up was in no way urban. At night you could hear bull frogs down on the pond, and crickets chirping, nothing too exotic.
Now living where we do I've heard some crazy noises at night. Thankfully my outdoors-men husband has been able to educate me on the noises. The past few nights we have been able to sleep with all the windows open allowing for all those sounds to trickle in along with the fresh air.
The newest one being an Easter Screech-Owl. Check out the link and give a listen. And by the way... it isn't as eerie a sound on this web site as it is at 4:00 am in the dark while you are attempting to fall back to sleep. SPOOKY would be the best way to describe it.