Here's a free idea for someone to run with: just as Zillow has a neighborhood "walkability" score prospective buyers might look at, there could be various pollution scores, including sound and light, sourced from some kind of Flock-like (ew) network of capture devices. Some folks are into mounting things like personal weather stations on their property, so maybe a new generation of devices capturing this type of data (with local signature-based identification of sources, and triangulation when the same thing is heard in multiple places, etc.) wouldn't be too far-fetched.
A modern US city has the combined problems of cheap construction of residential buildings, with insufficient unit-to-unit and exterior noise isolation (builders "don't care"), and near-zero enforcement of vehicle noise laws (police and muffler shops "don't care", drivers "want to" be loud).
Contrast this with, say, Germany or Switzerland, where concrete construction is the norm, noise laws are often strictly enforced, and a modified car would get pulled over quickly.