随着城市的发展、汽车的普及,噪声污染已对城市环境构成严重威胁。美国环境保护局(EPA)调查后发现交通(包括客运汽车、火车、公交车、摩托车、中型和重型卡车、飞机)是最主要的室外噪声源之一。在《噪声危害手册》一书中,EPA估计美国有超过1亿人受到家庭附近交通噪声的侵扰。 With the development of cities and the popularization of automobiles, noise pollution has posed a serious threat to the urban environment. A survey conducted by the U.S. Environmental Protection Agency (EPA) found that transportation (including passenger cars, trains, buses, motorcycles, medium and heavy trucks, and aircraft) is one of the major outdoor noise sources. In its Handbook on Noise Hazards, the EPA estimates that more than 100 million people in the United States are being harassed by traffic noise near homes.