Occupational Hearing Loss

Last updated April 12, 2017

What are the other Names for this Condition? (Also known as/Synonyms)

  • Noise-Induced Hearing Loss (NIHL) due to Occupation
  • ONIHL (Occupational Noise-Induced Hearing Loss)
  • Sensorineural Hearing Loss due to Occupational Hazard

What is Occupational Hearing Loss? (Definition/Background Information)

  • Occupational Hearing Loss (OHL) is a reduction in the ability to hear sounds, due to job-related damage from noise or vibration to the inner ear
  • Individuals related to trades that involve high sound levels, such as airline maintenance, military, construction, and farming are mainly affected. The condition is also related to the non-usage of ear protective gears, such as ear plugs or ear mufflers
  • Occupational Noise-Induced Hearing Loss (ONIHL) occurs mostly in males and is not related to age. However, it is related to the number of years of work in occupations that involve high noise levels (continuous exposeure)
  • The condition is initially symptomless. It gradually progresses to s stage where there is an inability to recognize speech in crowded areas. Occupational Hearing Loss can lead to permanent deafness and psychosocial complications, if preventive steps are not taken

Who gets Occupational Hearing Loss? (Age and Sex Distribution)

  • More than 72% of Occupational Hearing Loss cases arise in the manufacturing sector
  • The rate of hearing loss is greatest among new workers during the first 10 years of exposure and gradually worsens in their mid and late careers, leading to reduction in speech understanding
  • It is more prevalent in males, with no correlation to the age of an individual

What are the Risk Factors for Occupational Hearing Loss? (Predisposing Factors)

Following are the risk factors for Occupational Hearing Loss that involves repeated exposure to loud and high frequency sounds:

  • Airline maintenance crew
  • Farming
  • Mining
  • Construction
  • Orchestra
  • Military

Additionally the following factors may increase the risk:

  • Smoking, diabetes mellitus, hyperlipidemia, and exposure to ototoxic drugs
  • Individuals with variations in certain genes have higher susceptibility to OHL

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Occupational Hearing Loss? (Etiology)

Occupational Hearing Loss is caused by:

  • Working in occupations and trades with prolonged exposure to loud and high frequency sounds, such as airline industry, military, construction, agriculture, and music and entertainment industry
  • Prolonged exposure to noises resulting in damage and death of hair cells present in the inner ear, which is involved in sound amplification. Since the hair cells do not regenerate, the damage is permanent

What are the Signs and Symptoms of Occupational Hearing Loss?

During the initial stages, Occupational Hearing Loss (OHL) may be asymptomatic and hence, people fail to recognize it in the early stages.

  • After prolonged occupational noise exposure, the first sign to appear is the reduced ability to hear high-pitched sounds such as the singing of birds or understanding someone speak in a crowd with high-background noise
  • As the condition progresses, the severity of hearing loss increases and the individuals may not be able to hear high-pitched sounds
  • Other symptoms that may be associated include a sensation of ringing or fullness in the ears

How is Occupational Hearing Loss Diagnosed?

Occupational Hearing Loss may be diagnosed through a detailed medical history and physical examination. In addition to the above, following examinations and tests may be performed:

  • Audiometry: It is a diagnostic tool that tests the ability to hear sounds and is used for evaluation of OHL
  • Imaging tests, such as CT and MRI scans of the brain and ear canal, are used to rule-out other causes of hearing loss

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Occupational Hearing Loss?

Occupational Hearing Loss is associated with complications that include:

  • Permanent deafness
  • Emotional stress and depression
  • Increased risk of cardiovascular conditions
  • Higher risk of industrial accidents
  • Decreased productivity

How is Occupational Hearing Loss Treated?

Currently, there is no cure for Occupational Hearing Loss; hence, the goal of the treatment is to stall its progression and help individuals develop skills to cope with OHL. The treatment may involve:

  • Avoiding ‘high sound level’ occupations
  • Wearing ear protective gear while working
  • Developing lip reading skills
  • Using hearing aids

How can it be Prevented?

Prevention is the best form of treatment, since Occupational Hearing Loss can be a permanent condition. The preventative measures include:

  • Changing or switching to occupations that involve lower sound levels
  • Wearing noise protective ear plugs or ear muffs when working in a loud environment
  • Undertaking routine screening of individuals working in high sound environment
  • Ensuring that the industries strictly comply with implementation of prevalent statutory codes on occupational safety measures, especially with respect to workplace noise levels

What is the Prognosis of Occupational Hearing Loss? (Outcomes/Resolutions)

Even though Occupational Hearing Loss leads to permanent hearing disability, with appropriate early treatment, many individuals are able to lead a normal or near normal life.

Additional and Relevant Useful Information for Occupational Hearing Loss:

  • As of 2015, stem cell therapy tested in animal models for treating Occupational Hearing Loss is showing promising results
  • Noise-Induced Hearing Loss (NIHL) is the most common health place risk in USA with approximately 22 million workers being affected
  • Noise-Induced Hearing Loss due to Occupation is considered as an occupational disorder  and the employees may be eligible to receive compensation, if the employer fails to warn the employees about dangers from noise in the workplace or fails to offer adequate protective gear
  • There are many online groups available for individuals diagnosed with Occupational Hearing Loss that provide supportive care, encouragement, and bring a measure of relief to the affected individuals and their families

What are some Useful Resources for Additional Information?

National Institute on Deafness and Other Communication Disorders (NIDCD)
31 Center Drive, MSC 2320 Bethesda, MD 20892-2320
Phone: (301) 496-7243
Toll-Free: (800) 241-1044
TTY: (800) 241-1055
Fax: (301) 402-0018
Website: http://www.nidcd.nih.gov

Hearing Loss Association of America (HLAA)
7910 Woodmont Ave, Suite 1200, Bethesda, MD 20814
Phone: (301) 657-2248
Fax: (301) 913-9413
Website: http://www.hearingloss.org

Dangerous Decibels
University of Northern Colorado, Campus Box 140, Greeley, CO  80639
Phone: (970) 351-1600
Fax: (970) 351-2974
Website: http://www.dangerousdecibels.org

References and Information Sources used for the Article:

http://www.nlm.nih.gov/medlineplus/ency/article/001048.htm (accessed on 08/06/2015)

https://www.osha.gov/SLTC/noisehearingconservation/ (accessed on 08/06/2015)

http://www.cdc.gov/niosh/topics/noise/ (Accessed on 08/06/2015)

http://www.betterhearing.org/hearingpedia/hearing-loss-prevention/noise-induced-hearing-loss/ (accessed on 08/06/2015)

Helpful Peer-Reviewed Medical Articles:

Basner M, Brink M, Bristow A, de Kluizenaar Y, Finegold L, Hong J, Janssen SA, Klaeboe R, Leroux T, Liebl A, Matsui T, Schwela D, Sliwinska-Kowalska M, Sörqvist P. (2014)  ICBEN review of research on the biological effects of noise 2011-2014. Noise Health. 2015 Mar-Apr;17(75):57-82. doi: 10.4103/1463-1741.153373

Parker W, Parker V, Parker G, Parker A. (2014) 'Acoustic shock': a new occupational disease? observations from clinical and medico-legal practice. Int J Audiol. 2014 Oct;53(10):764-9. doi: 10.3109/14992027.2014.943847

Stucken EZ, Hong RS.  (2014) Noise-induced hearing loss: an occupational medicine perspective. Curr Opin Otolaryngol Head Neck Surg. 2014 Oct;22(5):388-93. doi: 10.1097/MOO.0000000000000079

Verbeek JH, Kateman E, Morata TC, Dreschler WA, Mischke C. (2014) Interventions to prevent occupational noise-induced hearing loss: a Cochrane systematic review. Int J Audiol. 2014 Mar;53 Suppl 2:S84-96. doi: 10.3109/14992027.2013.857436

Reviewed and Approved by a member of the DoveMed Editorial Board
First uploaded: Aug. 10, 2015
Last updated: April 12, 2017

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