Impact of Noise in the Workplace
Shift workers exposed to continuous loud noise on the job, such as crashing, machinery, or engines, or who come in contact with certain types of metals and solvents, face a higher risk of hearing loss than the average population. That’s saying a fair amount, since with the explosive popularity of iPods, specifically iPod earbuds, the average music listener faces far more hearing loss danger than they did a decade ago. As this generation of Baby Boomers ages, so many of whom work shifts and extended hours, rates of both natural and work-related hearing loss will likely surge across the country. Managers, employees and health care workers have to be prepared to diagnose potential hearing loss in themselves and others and take steps for prevention.
Over 30 million Americans are exposed to dangerous noise levels at work and an additional 9 million are at risk for hearing loss due to exposure to substances such as solvents and metals.
Shift workers face the same risks of hearing loss that we all face. But, they can also face an increased risk of hearing loss if their work environment provides exposure to high noise levels and if they do not follow appropriate protective measures. According to the National Institutes of Health, of the 28 million Americans who have some degree of hearing loss, about one-third can attribute their hearing loss, at least in part, to noise.
There are three attributes considered in evaluating hearing loss; type of loss, degree of loss and configuration of loss. Hearing losses are categorized based on the location of the auditory system loss; conductive hearing loss, sensorineural hearing loss and mixed hearing loss.
Types of Loss
Conductive hearing loss occurs when fluid builds up in the middle ear from a cold or allergy or when there is an infection in the ear canal, earwax build up or when a foreign body is present in the ear. Conductive hearing loss usually involves a reduction in sound level, or an ability to hear faint sounds. This type of hearing loss can often be medically or surgically corrected.
When there is damage to the inner ear or to the nerve pathways from the inner ear to the brain, sensorineural hearing loss occurs. This type of hearing loss cannot be medically or surgically corrected; it is a permanent loss. Sensorineural hearing loss not only involves a reduction in sound level, or ability to hear faint sounds, but also affects speech understanding, or ability to hear clearly. This type of hearing loss can be caused by diseases, birth injury, drugs that are toxic to the auditory system, and genetic syndromes. Sensorineural hearing loss may also occur as a result of noise exposure, viruses, head trauma, aging, and tumors.
Conductive hearing loss can occur in combination with a sensorineural hearing loss. In this case, there may be damage in the outer or middle ear and in the inner ear or auditory nerve. When this occurs, the hearing loss is referred to as a mixed hearing loss.
Degree of Loss
The degree of hearing loss refers to the severity of the loss. A person who can hear sounds across a range of frequencies at 0 – 25 dB has normal hearing. The thresholds for the different degrees of hearing loss are:
Normal hearing 0-25 dB
Mild hearing loss 26-45 dB
Moderate hearing loss 46-65 dB
Severe hearing loss 66-85 dB
Profound hearing loss over 86 dB
Configuration of Loss
The configuration of hearing loss refers to the extent of hearing loss at each frequency and the overall picture of hearing that is created. If only the low frequencies are affected, the configuration would show poorer hearing for low tones and better hearing for high tones. If only the high frequencies are affected, the configuration would show poorer hearing at high tones and better hearing at low tones.
Some hearing loss configurations are flat, indicating the same amount of hearing loss for low and high tones. Some hearing losses impact both ears, some only one ear. Some losses affect one hearing in one ear more than the other ear. A hearing loss may be sudden or progressive. Some hearing losses fluctuate; they get better or worse at certain times.
Age Related Impacts
- Although those 65 and older make up 12.5% of the U.S. population, they account for 37% of hearing impaired individuals 3.
- Some studies point to an increase in prevalence of hearing impairment among people age 45 to 69, especially in men 4.
- A study of children between the ages of 6 and 19 years found that 14.9% of them have hearing loss in one or both ears 5.
- Another study found that twelve percent of children and teens in the US suffer from noiseinduced hearing loss 6.
- Hearing loss due to noise appears during the first five to ten years of exposure, so young workers are at most risk of noise-induced hearing loss 7.
Symptoms of hearing challenges
The symptoms may include:
• Feeling dizzy and unbalanced
• Having fluid draining from the ear
• Being unresponsiveness to low-pitched sounds
• Becoming inattentive when others are talking
Also, some people are forced to live constantly with buzzes and hums that sound perfectly real and yet only they can hear them. Imagine never being able to escape those sounds. This odd condition, in medical lingo, is known as tinnitus. Tinnitus can also result from ear or sinus infections, an inner ear disorder called Meniere’s disease, certain medications, head and neck trauma, circulatory problems or misalignment of the jaw. In rare instances, a serious condition such as a tumor can cause these phantom sounds, so anyone experiencing tinnitus should see a doctor.
The National Institutes of Health, National Institute on Deafness and Communicative Disorders has ten questions that can help determine if an individual should be evaluated by a hearing specialist. See the NIH Ten Ways to Recognize Hearing Loss by logging onto http://www.nidcd.nih.gov/health/hearing/10ways.asp.
Preventing Hearing Loss at Work
• Be alert to hazardous noise in the environment
• Know which noises can cause damage
• Wear earplugs or other hearing protective devices when involved in a loud activity
• Make colleagues aware of the hazards of noise
• Have routine examinations by an otolaryngologist, a physician who specializes in diseases of the ears, nose, throat, head, and neck
• Periodically have a hearing test by an audiologist, a health professional trained to identify and measure hearing loss and to rehabilitate persons with hearing impairments
Other Interesting Information
Scientists with the federal National Institute for Occupational Safety and Health 8 reported on a new study at a scientific conference held during the week of June 24, 2006. Their study of more than 5,000 people (the largest study of its type) who had hearing tests from 1999 through 2004 as part of an annual federal health survey confirmed the following results of smaller studies:
• Black adults hear better than white adults; the scientists suspect that melanin, a skin pigment, plays a role in how the body removes harmful chemical compounds caused by damage to the sensitive hair cells in the inner ear. On average, the 1,077 non-Hispanic blacks in the study could hear higher tones at 15 to 22 decibels, while the 2,518 non-Hispanic whites could hear high-end tones at 21 to 32 decibels, on average, the study found.
• Women of all races hear better than men; this may be due to reduced exposure to noise or to genetics.
Hearing Health Quick Test
Choose YES, NO or SOMETIMES for each question, then use the instructions at the end of the test to calculate your score.
1. Do you find it difficult to follow a conversation in a noisy restaurant or crowded room?
Yes No Sometimes
2. Do you sometimes feel that people are mumbling or not speaking clearly?
Yes No Sometimes
3. Do you experience difficulty following dialog in the theater?
Yes No Sometimes
4. Do you sometimes find it difficult to understand a speaker at a public meeting or a religious service?
Yes No Sometimes
5. Do you find yourself asking people to speak up or repeat themselves?
Yes No Sometimes
6. Do you find men’s voices easier to understand than women’s?
Yes No Sometimes
7. Do you experience difficulty understanding soft or whispered speech?
Yes No Sometimes
8. Do you sometimes have difficulty understanding speech on the telephone?
Yes No Sometimes
9. Does a hearing problem cause you to feel embarrassed when meeting new people?
Yes No Sometimes
10. Do you feel handicapped by a hearing problem?
Yes No Sometimes
11. Does a hearing problem cause you to visit friends, relatives or neighbors less often than you would like?
Yes No Sometimes
12. Do you experience ringing or noises in your ears?
Yes No Sometimes
13. Do you hear better with one ear than the other?
Yes No
14. Have you had any significant noise exposure during work, recreation or military service?
Yes No
15. Have any of your relatives (by birth) had a hearing loss?
Yes No
To calculate your Hearing Health Quick Test score, give yourself:
• 2 points for each Yes answer
• 1 point for each Sometimes answer
• 0 points for each No answer
Scores of 3 or more may mean that you have a hearing problem.
Scores of 6 or more strongly suggest that a hearing check is warranted.
In either case, ask your doctor to screen your hearing. Further testing by an audiologist may be recommended.
1 Center for Disease Control; http://www.cdc.gov/niosh/hearloss.html
2 American Speech-Language-Hearing Association; http://www.asha.org/public/hearing/disorders/types.htm
3Center for Disease Control; http://www.cdc.gov/nchs/data/agingtrends/02vision.pdf
4 Wallhagen MI, Strawbridge WJ, Cohen RD, Kaplan GA. Am J Public Health; 87;440-442, 1997
5 Amanda Sue Niskar,, Stephanie M. Kieszak, Alice E. Holmes, Emilio Esteban, Carol Rubin, and Debra J. Brody, PEDIATRICS Vol. 108 No. 1 July 2001, pp. 40-43
6 http://www.newstimeslive.com/features.php?section=Everything+Kids&id=638
7 http://www.safe-at-work.com/SafeAtWork/96-110/96-110f.htm#eb2
8 U.S. National Institute for Occupational Safety and Health; Cincinnati study 2006; presented at a recent meeting of the Acoustical Society of America
©2006workingnights
This material is provided for personal, non-commercial, educational and informational purposes only and does not constitute a recommendation or endorsement
Tags: chronic problems, health care prevention, hearing loss
