The controversial Anglo-French supersonic transport plane, the Concorde, had attracted muc
What bothers noise experts is that plenty of commonplace machines are just as loud as, or even louder than, the Concorde. A sanitation truck can be noisier, and so can a heavy diesel truck pulling away from a stop sign. One expert who has gone out of his way to dramatize the prevalent offensiveness of the city sound-scale is Dr. Thomas H. Fay, director of speech and hearing at Columbia-Presbyterian Medical Center in New York. Dr. Fay took a sound-meter into a New York City subway and proved that an approaching train can be twice as loud as the Concorde.
Since World War Ⅱ, the number of the high-powered noise-makers, from trucks and motorcycles to air conditioners and sirens has increased almost geometrically. It' s no wonder that in many areas of the country, especially in the suburbs, the average sound level has doubled in 20 years. Noise experts estimate that city noises are increasing a half-decibel a year. They found that in 1971 the quietest parts of Los Angeles--thought to be a relatively quiet city--were louder than the loudest districts of New York in 1937.
This passage mainly talks about ______ .
A.the problem of the supersonic transport plane, the Concorde
B.a comparison between the Concorde and other machines
C.the problem of noise
D.noise in the suburbs