| a lot the noise reduction that you write of is a result of foam insulation in the buildings and better windows. the standard windows in new buildings, even residential, is two panes of glass filled with either xenon gas or vacumn, which is used for both noise reduction and energy conservation. if a building faces a highway or some other high noise area, they are required to have even better windows. a lot of the buildings here also have dampering systems that emit frequencies to counteract traffic noises in addition to the air conditioning, computer sounds, and other background noises that make the environment seem quieter than it actually is. |