There's an app opportunity here. Write something which captures audio, timestamps it with millsecond accuracy, annotates it with GPS info, and sends it to a web site for correlation. When you want to find some noise source, get a few people to walk around running this app. Then the site can locate it from the time differences, with a much longer baseline than human inter-ear distance.
Love this idea. My first thought is that calibrating mics could be difficult. I wonder how good existing decibel meter apps are
Multipath always makes a delay longer, not shorter, which helps in resolving ambiguity in areas with reflective building walls.