According to studies, the noisiest cities are the largest ones (those with a population in excess of one million). The quietest among them is Phoenix, AZ at only 47.2 dBA. Chicago, IL is on the other side of the scale – the average noise level here is 54.8 dBA.
The Anchorage municipality is technically the quietest city with a population greater than 250,000; the average noise level here is 34.5 dB, which is more in line with the numbers encountered in small villages. Bakersfield, CA is as quiet as it gets in the continental U.S. in this category (40 dBA). Milwaukee, WI tops this group at 56.1 dBA.