Protecting Employees from Noise-Induced Hearing Loss: Effective Workplace Noise Control for Health and Safety 

A noisy workplace is more than just an annoyance. It has many significant health and safety risks far beyond what you might imagine, both for physical and mental well being. 

It is vital for businesses to conduct a workplace noise control risk assessment and identify potential hazards related to excessive noise exposure. In South Africa, employers must comply with the Occupational Health and Safety Act and the Noise Induced Hearing Loss Regulations, 2003, by implementing engineering, administrative, and PPE controls to reduce noise exposure. 

Click here training course details: Noise: Measurement & Effects Core BOHS M503  

Let’s start with some of the health risks that arise with prolonged noise exposure in the workplace. 

• Noise-Induced Hearing Loss (NIHL) 

This is the most well-known and common health risk. Continuous or repeated exposure to loud noise can damage the delicate hair cells in the inner ear, leading to permanent hearing loss. This condition is typically gradual and irreversible. 

• Increased Risk of Cardiovascular Problems 

Noise exposure, particularly over long periods, has been linked to an increased risk of cardiovascular diseases. The mechanisms behind this include stress, elevated blood pressure, and changes in heart rate. 

• Increased Stress Levels 

Noise acts as a constant stressor to the body, causing both psychological and physiological responses. 

• Sleep Disturbances 

Noise is a known disruptor of sleep quality and quantity. Prolonged exposure to high noise levels, particularly at night, can interfere with sleep patterns. 

• Impaired Cognitive Function 

Chronic noise exposure can negatively impact cognitive abilities, especially in environments like schools or workplaces. 

• Increased Risk of Mental Health Issues 

Exposure to chronic noise has been shown to contribute to mental health problems, particularly anxiety and depression. 

• Hearing Fatigue 

Even if not leading to permanent hearing loss, prolonged exposure to loud noise can cause temporary hearing fatigue or discomfort. 

• Physical Fatigue 

Noise can contribute to physical fatigue due to the constant strain on the body from trying to hear or focus in a noisy environment. 

• Reduced Social Interaction 

Prolonged exposure to noise can also impact social interactions and relationships. 

Conducting a Workplace Noise Risk Assessment  

What you don’t know, you can’t fix, so assessing is key. With so many possible health repercussions, a workplace noise risk assessment must be put in place. This is a systematic process used to evaluate the noise levels in a workplace and determine the potential risks to employees’ hearing and overall health. 

This assessment is an essential part of occupational health and safety programs, especially in environments with high noise levels (e.g., manufacturing, construction, or entertainment industries).  

Steps to conduct a workplace noise risk assessment: 

1. Identify Noise Sources

The first step in the assessment is to identify all sources of noise in the workplace. These sources may vary depending on the industry but could include machinery, tools, ventilation systems, vehicles, and even employee activities. 

2. Measure Noise Levels

Measuring the intensity and duration of noise exposure is critical to assessing risk. Noise levels are typically measured in decibels (dB), and the risk of hearing damage increases as both the intensity and duration of exposure increase. 

3. Evaluate Employee Exposure

The goal of the risk assessment is to evaluate how much noise each employee is exposed to during a typical workday. This includes both the noise levels and the duration of exposure. Find out about individual noise measurement using a noise dosimeter here. 

4. Assess Potential Health Risks

Based on the identified noise levels and exposure durations, assess the potential risks to employees’ hearing and health. 

Hearing Damage Risk: Use the noise exposure data to assess whether employees are at risk for noise-induced hearing loss (NIHL). Compare the measured noise levels to safety standards such as those from OSHA (Occupational Safety and Health Administration), the WHO (World Health Organization) and South Africa’s Noise Induced Hearing Loss Regulations, 2003. 

5. Review Current Control Measures

Review any existing measures in place to mitigate noise exposure, such as engineering controls, administrative controls, and personal protective equipment (PPE). 

6. Recommend Additional Control Measures

Based on the findings of the risk assessment, develop recommendations for additional noise control measures to protect employees. 

7. Implement a Hearing Conservation Program

If the noise assessment reveals that noise levels exceed regulatory limits (usually 85 dB A-weighted for an 8-hour workday), employers should implement a hearing conservation program, which includes: 

• Regular Hearing Tests: Conduct baseline and periodic hearing tests to monitor any changes in employees’ hearing over time. 

• Noise Monitoring: Continue monitoring noise levels and adjust control measures as needed. 

• Hearing Protection Training: Train employees on the proper use and care of hearing protection devices, including the importance of consistent use in noisy areas. 

8. Monitor and Review

The noise risk assessment should be a continuous process as workplace environment, equipment, and tasks may change over time. 

Regulatory Compliance in South Africa 

Compliance with noise regulations is governed primarily by the Occupational Health and Safety Act (OHSA), 1993, and the Noise Induced Hearing Loss Regulations, 2003. 

Key aspects of these regulations include: 

Permissible Noise Exposure Limits 

Under the Environmental Regulations for Workplaces (2004) and the Noise Induced Hearing Loss Regulations,2003, the following noise exposure limits are defined: 

• 85 dB(A): The threshold level for hearing protection. Employees exposed to noise levels at or above 85 decibels (dB) over an 8-hour workday must wear hearing protection. 

• 90 dB(A): The maximum permissible noise exposure for workers over an 8-hour period. This limit is considered the upper threshold for continuous exposure without causing hearing damage. 

• 115 dB(A): For any noise levels above this threshold, the time of exposure should be limited to 15 minutes or less. 

These limits are based on an exchange rate of 3 dB, which means that for every increase of 3 dB, the allowable exposure time is halved. For example, at 88 dB, the recommended exposure time is 4 hours, and at 91 dB, it is 2 hours. 

Monitoring and Record Keeping 

Employers are required to maintain records of: 

• Noise Exposure Levels: Accurate records of noise measurements and assessments. 

• Health Surveillance: Regular audiometric testing to monitor employees’ hearing health. 

• Training: Documentation of training provided to employees on the risks of noise. 

We can appreciate that we CAN hear everyday noise, but noise induced hearing loss and other health ramifications are almost always preventable.