There is a road in Northern Minnesota called Gunflint Road. One can actually get to a place where the sounds of cars and trucks and airplanes disappear. It is an experience that I also had right after 911 when all air flight was grounded. It does not last for long. Standing still, just listening, after a few minutes there will be another car or truck on Gunflint, but the temporary lack of human traffic, no dogs barking, and only trees, birds, wind and insects is a shock.