Industrial Music

It can be permanently damaging to workers' hearing, but a five-step process of assessment and response will prevent this.

• By Barry R. Weissman
• Oct 01, 2006

WHAT do singers Mick Fleetwood, Barbra Streisand, Engelbert Humperdinck, Phil Collins, and Bob Dylan have in common with ex-president Bill Clinton and actors William Shatner and Leonard Nimoy? And what do they all have in common with television personalities David Letterman and Peter Jennings? All of them lost some of their hearing.¹

"Huh?" she said.

"How many times do I have to repeat it for you? I said that they suffer from hearing loss."

Many of our employees could be suffering the same fate and not realize it. Noise and its effects on the human ear are generally slow and unrealized until something happens to make us aware. What's worse is that our children may be losing their hearing as they grow up. Many, many children are using various music devices that have "ear buds" or headsets. In their quest to be tuned-in, they have the music turned up while they listen.Next time you're in your car, make this test. As you exit the car for the night, leave the radio volume control set to where you were listening to it at the end of the day. The next morning, as you get into the car, notice the sound level of the radio. Does the sound seem too loud, or is it OK? If you are like many working people, the sound is probably too loud in the morning, and you have to adjust the volume downward.

Why?
As we go through the day, our ears pick up all of the noise that surrounds us. Sound waves are funneled by the outer ear along the exterior canal toward the eardrum (tympanic membrane). The vibrations of the eardrum are passed along to the three smallest bones in the body, called the hammer, anvil, and stirrup. The stirrup connects to the cochlea, which is a spiral-shaped tube filled with delicate hair cells. When we are exposed to loud noises, these hair cells try to absorb some of the sound energy but are beaten down. If the exposure is of a short duration, then the cells have a chance to rest, and they rejuvenate and can do their job. However, if the sound levels continue to be excessive, the hair cells do not get a chance to rest, and they begin to die. As they die, we lose parts of our hearing.²

So after a day at work, you enter your car and need to turn the radio volume up so you can hear it. In the morning, after a quiet night, the cochlea's hair cells have rested, and now the radio volume is too loud.

In the case of William Shatner and Leonard Nimoy, they lost their hearing due to being too close to an explosion on the "Star Trek" set. That is a severe acute exposure. In the case of the music stars, they had chronic exposures--long-term, excessively loud exposures.

In the case of our children, "the original [portable] . . . cassette players . . . [had] a maximum duration of two hours, while portable CD players give up to 80 minutes a disc. A typical MP3 player, however, can store up to 300 hours of music and has batteries that last for 12 hours before needing to be recharged."³ Our children are being exposed just as the music stars are: chronically.

What?
What is the difference between noise and sound?

The "American Heritage Dictionary of the English Language"⁴ says noise is "A sound of any kind, especially when loud, confused, indistinct, or disagreeable," while sound is defined as "A vibratory disturbance in the pressure and density of a fluid." In another definition, a friend said sound is something that I like and noise is just noise--sounds that I don't like.

What happens in the workplace, and why do we have to worry about this? Many of our work sites use equipment that makes noise. Some equipment makes a lot of noise, and some doesn't. So what do we need to do?

OSHA regulations in 29 CFR 1910.132(d)(1) require that the employer "assess the workplace to determine if hazards are present, or are likely to be present, which necessitates the use of personal protective equipment." If required to do a hazard assessment of a metal stamping operation, most of us know a stamping press makes a lot of noise and wouldn't hesitate to require the use of hearing protectors. But what about some other equipment? What about a papermaking machine or a plastics extruder? Or any other equipment that we have in our facilities?

What should we do if our assessment tells us that we have loud noise? How loud does it have to be? To answer that question, we need to review the Occupational Noise Exposure standard at 29 CFR 1910.95.

First, we look at how loud the noise is and what is the duration of the noise. Table G-16 in the OSHA regulations⁵ tells us the limit and the duration of the noise levels.

Second, during our hazard assessment, we will be taking measurements of the noise levels. If those levels show that employees are exposed to a time-weighted average (TWA) of more than 85 dBA for eight hours, the company is required to develop a hearing protection program for its employees. In developing the program, the company needs to first look at engineering controls and/or administrative programs before it allows the use of PPE in the form of hearing protection.

The hearing protection program needs to include the following topics:⁵

• How and when monitoring of the work areas will be performed
• Notifying the employees of their results
• Informing the employees of the need to have their hearing tested (at no cost to the employees and on company time)
• What the employees need to do to work safely (i.e., what are the engineering controls that help protect the employees, what are the administrative programs they need to follow, and lastly what PPE they will be using)
• What will be included in the training program
• Informing the employees they can have access to this information and their test results
• How will the records of the monitoring, testing, and training be kept

If a company needs help in developing a hearing protection program, it can hire a consultant, subscribe to a Web site,⁶ or just follow along in the regulations developing its own requirements for each item.

Third is engineering controls. Engineered solutions take the vagaries out of protection so the employee doesn't have to think about what he needs to use to protect himself when working in and around equipment. Some examples would be how we separate the employees from the noise source: Can we put them inside a control room, or can we put the noise-producing part of the equipment into an enclosure?

Fourth is administrative programs or work practices. If engineering controls are not practical, can we split the work so no one person is exposed to more noise than it is allowed for a specific period of time. Rather than keep one person working at the same noisy machine for the full eight-hour shift, split the job and have the employees rotate out of the noisy environment. This does two things: The employees will not be overexposed to noise, and they may have a better appreciation of the job because they have a chance to rotate their work assignments. They may not get bored.

Fifth is follow-up. Hearing tests are required on an annual basis. The training is required on an annual basis. The program may need to be modified and should be reviewed as necessary, but at least on an annual basis.

Noise-induced hearing loss is 100 percent preventable. Once acquired, however, hearing loss is permanent and irreversible.⁷ There was a poster that reminded me of this when I saw it in England a number of years ago. It showed a scantily clad young lady with a caption that read, "If she said 'yes,' would you be able to hear her?"

This article appeared in the October 2006 issue of Occupational Health & Safety.

References

1. "Famous baby boomers with significant hearing loss and/or tinnitus," www.hear-it.org/page.dsp?page=2649.
2. Suter, Alice H. Hearing Conservation Manual, 3rd Edition, 1993. CAOHC, Milwaukee, pp. 16-17.
3. Gray, Richard, "Digital music craze stores up ear trouble for iPod fanatics," May 8, 2005, www.4hearingloss.com.
4. Morris, William, Editor, American Heritage Dictionary of the English Language, 1969. New York, pages 891 and 1234.
5. 29 CFR 1910.95, Occupational Noise Exposure, www.osha.gov.
6. Two subscription Web sites that may be of help are www.kelleronline.com and www.safetysmartonline.com.
7. Noise page, NIOSH Web site, www.cdc.gov/niosh/topics/noise.

This article originally appeared in the October 2006 issue of Occupational Health & Safety.