Cities are loud, cars are one (major) reason, but not the only one. I lived in a downtown area in a high-rise. 2am in the morning, no cars running but the hum

Cities are loud, cars are one (major) reason, but not the only one. I lived in a downtown area in a high-rise. 2am in the morning, no cars running but the hummming of all the equipment necessary to operate a city is noise pollution. Next, light pollution.