My buff orps are quiet, so are my golden comets and barred rocks. Stay away from Black Australorps if you want a quiet chicken. Ironically, my Black Australorp roo is basically silent. A darn good rooster, but the girls are LOUD. They scream over everything (and they have a sound like a screaming infant). The waters too warm WAAAAAA The food is getting low WAAAAAAAA a butterfly is flying too close to the coop WAAAAAAAAAAAAAA Yeah it's that bad.
However, I agree. If you want a quiet animal during an apocalyptic type situation, may want to stick with rabbits (or you can take turns guarding the coop... booby trap it, move it to the furthest corner of your property away from the road, dunno... gotta be creative. During that type of a situation, it wouldn't matter what type of livestock you have because people will likely attempt to loot your house anyway and find them.