Noise hazards

Noise hazards Workers compensation claims for noise induced hearing loss have been on the rise since 2010, and employers struggle to provide employees with adequate protection. Estimates from the United States Army and the Center for Disease Control show more than four million workers are exposed to damaging noises every day, and over 22 million are exposed to serious potential damage in a year.

Employers can address potential noise hazards for their employees through an understanding of the causes of noise induced hearing loss and a commitment to upholding safety standards at all times.


Hearing loss attributed to loud noises in the workplace comes from one of two sources. A single, catastrophic incident, such as an explosion or crash, may cause an immediate loss of hearing. The second cause is long-term exposure to loud sounds, like tools or motors, which gradually decay the employee’s sense of hearing. Singular incidents are the least common complaint among workers.

The National Institutes of Health recognizes 85 decibels as the standard for hearing loss. An employee who experiences 85 dB or higher for more than eight hours a day will expect to suffer from permanent damage, especially if the employee is overly close to the source of the sound. OSHA guidelines prohibit prolonged exposure to loud sounds, and set clear limits on the amount of time each day an employee may work in a loud situation. Employers are required to provide hearing protectors for employees exposed to 8-hour noise levels of 85 dB or above. Employees may work 8 hours per day at 90 dB, with every 5 dB increase halving the time of allowed exposure. No employee can work at 140 dB unprotected for any length of time.

How Hearing Loss Occurs

Loud noises lead to hearing loss through damage to the auditory nerve and the hair cells in the ear. When sound first enters the ear, the wave is converted to fluid vibrations by the bones of the middle ear in the cochlea. The vibrations eventually cause the cochlea to ripple, forming a wave to move across the hair cells on top of the basilar membrane. Atop the hair cells sit stereocilia, which react to the moving wave and create the electrical impulses that travel to the auditory nerve.

Overexposure to loud sounds prevents the normal function of the hair cells and the auditory nerve. Loud sounds cause the hair cells to vibrate too violently, leading to damage and eventual death of these cells. Unfortunately, they are some of the rare cells in the body that do not regenerate. In addition, loud sounds can wear thin the layer of myelin that coats the auditory nerve. Thinning the myelin increases the distance electrical impulses must travel as they pass between synapses, which leads to a degradation of a person’s hearing.

Signs And Issues

The signs of noise induced hearing loss take time to develop, and may not be noticeable right away. Those affected by hearing damage will begin to notice a difference in the quality of their hearing when they compare the level and quality of hearing over a period of time. Often patients are the best source of diagnosis for their hearing loss, because they are intimately aware of any changes.

As hearing loss progresses, patients begin to exhibit signs such as:

  • Constantly asking for repetition
  • Requesting others to “speak up”
  • Notice others sound muffled or far away
  • Difficulty filtering out background noises in public areas
  • Increasing television volume
  • Ringing ears (also known as tinnitus)
  • Trouble hearing the high pitched sounds of women or children

Hearing loss then leads to other issues in the patient’s life that affects the patient’s quality of life. People with hearing loss often suffer from emotional problems brought on by the stress of difficulty communicating. Eventually, many patients withdraw from contact with others to avoid embarrassing situations.

Treatment And Prevention

Damage to the hair cells in the ear is permanent, and there is little that can be done to reverse the hearing loss. Some advancements have been made to reduce the impact damaged myelin has on hearing, but there is still a long way to go before treatments are routinely successful. Further research into the development of hair cells in the body could possibly lead to breakthroughs that help those cells regenerate after damage.

The only way to combat noise induced hearing loss is for employers and employees to practice safe noise policies at all times in the workplace. Doing so requires both groups to identify all potential noise hazards and institute a training program to point out the hazards. Then, employers must design the workspace so employees are as far from loud noises as possible. Finally, both employees and employers must ensure the proper use of ear safety equipment, properly rated for the noise level of the machine or situation.

Employees who believe they’ve suffered from noise induced hearing loss must see a doctor right away, in order to prevent an escalation of the problem.

Hearing loss in the workplace is an issue for both employers and employees. Employers limit the risk to their staff by creating safe working environments, but it is also the responsibility of employees to utilize safety equipment and follow safe noise protocols. When both sides work together, they minimize the risk of hearing loss.

Learn More

Learn to identify and analyze potential workplace hazards, infractions and risks through a bachelor of science in occupational safety online. At Eastern Kentucky University, you will gain a graduate-level education by industry-experienced educators and fire and safety professionals who are committed to teaching and preparing you for continued success.


Hearing Center of Excellence

Noise And Hearing Loss Prevention

Noise Induced Hearing Loss