Lehman, B.A. (1990, February 5). Some sound advice: Noise levels and hearing loss. The Boston Globe, p. 25.
OVERVIEW
According to Lehman
We know not to look directly at the sun, even during an eclipse, because the intense light will blind our eyes. But many of us are less aware that hearing is sensitive, too, and can be irreparably damaged by noise.
Loud music and household sounds seem to damage the very young. Judy Montgomery, Fountain Valley (CA) Director of Special Education, tested students in her district with following results:
The Army has had to lower its standards of hearing to reflect the damage done to young people.
The 1990 National Institute of Health Conference warned Americans about the dangers of hearing loss, especially early in life, and of the U.S. government’s leniency in regulating noise in the workplace.
The article continues:
Noise can damage many parts of the ear but does particular damage to the tiny, hairlike structures in the inner ear that respond to sound. The damage is insidious; it seldom hurts, it’s gradual, and by the time it’s noticed, the loss of hearing can be extensive.
Except for the trauma of a single extremely loud sound, such as a gunshot or firecracker exploding near your ear, noise usually doesn’t cause total deafness. Instead, it steals your ability to perceive high-frequency sounds. Those sounds make the difference between knowing someone is talking and understanding what they’re saying.
‘A general rule of thumb is that if the sound is loud enough that you would have to raise your voice uncomfortably to communicate with somebody, then if that sound were to continue for a significant number of hours, it would be potentially damaging,’ says NIH member and consultant, Julia Doswell Royster, expressing a consensus of experts at the conference.
Noise is measured in decibels, which operate on a logarithmic scale—every 6-decibel increase represents a doubling of sound intensity. A 20-decibel increase indicates a 10-fold increase, and the difference between 50 and 130 decibels is a 10,000-time rise in sound pressure.
Decibels
Examples and Effects
50-70
Normal conversation, quiet office.
70
Intrusive, interferes with telephone use.
80
Annoying, interferes with conversation. Constant exposure may cause damage.
85
Eight-hour exposure can cause hearing damage.
70-85
Vacuum cleaner, hair dryer, dishwasher, city traffic.
85-99
Lawnmower, subway, motorcycle, food blender.
90-100
No more than fifteen minutes unprotected exposure recommended.
100+
Regular exposure for more than one minute risks permanent hearing loss.
100-120
Snowmobile, chainsaw, jackhammer,
dance floor, boom box, ordinary rock concerts.
125
Threshold of pain.
120-145
Extra loud rock concerts, jet takeoff, shotgun blast.
Since experts and agencies such as the American Speech-Language-Hearing Association charge the government with indifference, the public needs to act on its own. What can one do about noise pollution and hearing damage?
- Consider noise in the workplace, where noise accumulates.
- Take seriously the hazard of leisure and home noise.
- Purchase sound-blocking ear muffs or special foam ear plugs—neither cotton nor ill-fitting ear plugs will help (ear plugs dampen only 25% of sound decibels).
- Keep home music at moderate levels and do not sit near the speakers at a rock concert. Use ear plugs.
- Radio and electronic supply stores carry inexpensive sound meters.
- For information and referrals for testing, call the American Speech-Language-Hearing Association, 1-800-638-8255.
- For a free pamphlet on noise protection, send a self-addressed, stamped envelope to Hearing Protection, American Academy of Otolaryngology, 1 Prince Street, Alexandria, VA 22314.
QUESTIONS FOR REFLECTION AND DISCUSSION
IMPLICATIONS
Why do people take more chances with their ears and than their eyes?
What do you most like hearing? What loss of sound-discrimination would make you unhappy? What personal losses would growing deafness bring you?
What have you already done and what steps do you intend to take to protect your hearing?
- Young people tend to feel indestructible. Hearing loss can come imperceptibly, and it is not a main fear for most. It is hard to protect one’s 70-year physical condition and happiness in the teen years.
- Hearing education is an important and neglected element in many curricula.
Dean Borgman cCYS