I was surprised at how noisy my backyard is in my sleepy residential neighborhood. My house is well-insulated and really quiet. I occasionally here my dog bark (he lives outside), but I did realize there are 6-8 distinctive dog voices in my neighborhood (maybe more) and they carry on a conversation off and on all night. Also have the occasional motorcycle or loud truck (we live 300 yards from a fairly major road). Lots of teenagers in the neighborhood, so some comings and goings (voices, laughing, car doors slamming) until 2am or so on the weekends.
"We do not go to the green woods and crystal waters to rough it; we go to smooth it." -- Nessmuk