Hearing specialists used to worry about loud noise as a cause of deafness only in industrial and military situations. They knew that eight hours of daily exposure, year in and year out, to the noise of the proverbial boiler factory would eventually result in permanent, or irreversible, hearing loss.
People who used drills were particularly susceptible. Then they learned that the same thing happened to aviators. And after jets came into existence, the hazard applied to ground crews at airports and flight-deck personnel aboard aircraft carriers – hence came the introduction of insulated, noise-absorbing plastic earmuffs.
In discotheques and rock ‘n’ roll joints, the trouble is not so much in the instruments themselves, or the small area. The blame goes to the electronic amplifiers. An old-fashioned military band, playing a march in Central Park, generated as much sound.
However, the sound was not amplified, but was dissipated in the open air. A trombonist sitting in front of a tuba player might be a bit deaf for an hour or so after a concert; then his hearing returned to normal. A microphone hooked up to a public address system intensified the sound but did not appreciably increase the hearing hazard. What did was multiple mikes and speakers, and the installation of internal mikes in such instruments as guitars and bousoukis.
The man who had the problem closest to home, and studied it there, was George T. Singleton, an ear, nose and throat man at the University of Florida. He noticed that, when he picked up his teenage daughter Marsha after a dance, she couldn’t hear what he said in the car on the way home. Singleton recruited a research team and tested the hearing of ten fourteen-year-old ninth-graders an hour before a dance.
Then, the investigators went to the dance hall, and found the average sound intensity to be very high in the middle of the dance floor. Directly in front of the band, it peaked to extremely high levels. The test crew had to move forty feet outside the building before the level dropped to a safe, but still uncomfortable, level.
After the dance, the kids’ hearing was tested again. Despite the youthful resiliency of their inner ears, all had suffered at least temporary hearing impairment. The greatest damage was in the high-frequency speech range, involving consonantal sounds, similar to the loss felt by oldsters who complain that “everybody mumbles nowadays”.
Why do the youngsters immerse themselves in noise that is so uncomfortable to their elders? A Florida teenager explained: “The sounds embalm you. They numb you like tranquilizers. You don’t want to hear others talk. You don’t want to talk. You don’t know what to say to each other, anyway.” So, why listen? And, eventually, how?
A. Mark the best choice.
1. Line 6, They’ refers to .
a) people who used drills
c) workers in the boiler factory
b) people exposed to loud noise
d) hearing specialists
2. To be ‘dissipated* (line 15) means to .
a) be made inaudible
c) be tolerated
b) become less or disappear
d) become safer
3. Line 20, ‘internal mikes’ means .
a) a group of microphones used to amplify the sound
b) speakers to which musical instruments are connected
c) the strings of instruments like guitars and bousoukis
d) microphones inside musical instruments
4. If something ‘numbs’ (line 41) you, .
a) it makes you unable to speak
b) you can’t decide how to behave
c) you don’t feel any physical sensation
d) it makes you unable to hear
5. led to the introduction of insulated, noise-absorbing plastic earmuffs.
a) The hazards of airports
c) The introduction of jet airplanes
b) The noise of aviators
d) Aircraft carriers
6. Old-fashioned military bands were different from discotheques and rock ‘n’ roll joints in that .
a) they only played marches in big parks
b) the sound the instruments produced was not amplified
c) they had fewer instruments
d) they didn’t generate a lot of sound