参考答案：A

解析：[听力原文] 16-20
Modern life is full of nasty noises, especially in the cities. Sirens can shatter serenity at any moment and jack-hammers, loud music, and useless mufflers can all send us over the edge. For many people in New York City, there’s one form of sonic pollution at the top of the list. They’re calling for its banning, even though some nervous New Yorkers savor the sound for security reasons. It’s late. You’re tired. Finally, after an exhausting day, you’re ready to surrender to the world of dreams. Your head sinks into your pillow. Then, a big alarm! After being awakened at night many times so that you’ve just gotten to sleep and then the alarm goes off. Each night hundreds of people, who live in Brooklyn, are jolted out of their sleep by the nagging wail of a car alarm.
You just wait it out but you don’t know if that’s going to happen again. You don’t know when you’re going to be reawakened for a second or a third time even. And sometimes a defective alarm will go one for hours.
A music producer and composer, this resident of Manhattan’s Upper West Side got fed up with car alarms disturbing his sleep and his work. He got together with some similarly frazzled neighbors and formed a posse of sorts. They start off with a note saying, "Fix your car alarm, it’s disturbed hundreds of people last night." If that doesn’t help, they quite often use some minor retaliatory step like breaking an egg on their windshield or on the front hood, which doesn’t hurt anything but it’s a little bit of a mess to clean up.
The "egg man," who prefers to remain anonymous, says some vigilantes take even more drastic action. Like smearing axle grease on door handles. Another classic is to smear Vaseline all over the windshield, which is incredibly hard to get off. In other neighborhoods there might be even broken windshields and things like that. A young lady was a target of vigilante retribution. It happened one night when, unbeknownst to her, the car alarm malfunctioned. In a worse case, a car owner noticed that on the passenger front door, there were a lot of dent marks. It looked like the heel of someone’s shoe, as if someone had kicked the innocent car, because the alarm hadn’t even been going off all night. The repairs cost her a couple of hundred dollars.
Most people I talked to believe that the car alarm produces no effect it has been intended to. To test the theory, a woman set off her alarm in a restaurant parking lot. Not a single person bothered to see if a car was being broken into. Are car alarms really effective She says absolutely not, not even when she called the police. One night, there was a real incredible racket, and a little MG was being mutilated to death. The alarm was going off. So she called 911. Well about 40 minutes later, the police drove up. Little remained of the car by them.
The streets are much noisier than before. Many people complain that the noise affects not only their ability to sleep at night, but for the most part their ability to work during the day. And even parents have started to complain, "What is the impact on children " And there are more and more studies that show that young people in particular, that are exposed to a sustained amount of loud noise, have hearing loss. So it’s a health issue, it’s a quality of life issue.
Enforcement of existing laws, along with new regulations, may be cutting down noise in some neighborhoods. It’s now illegal for alarms to run for more than three minutes. After that police can break into a car to disable the alarm or even tow away a wailing vehicle. It’s hoped these actions will motivate car owners to adjust their alarms, making them less sensitive so vibrations from passing trucks and the like don’t set them off. Even the egg man admits the car alarm situation has improved, at least in his neighborhood.

16. What form of sonic pollution is this report concerned with