Essential Guide to Measuring Workplace Noise Levels for Employee Health and Safety
- tass peters
- Dec 16, 2025
- 3 min read
Workplace noise can pose serious risks to employee health and safety. Excessive noise exposure leads to hearing loss, increased stress, and reduced productivity. Measuring noise levels accurately is the first step to managing these risks and creating a safer work environment. This guide explains how to measure workplace noise effectively, what tools to use, and how to interpret the results to protect employees and comply with safety regulations.
Why Measuring Noise Levels Matters
Noise is more than just an annoyance. Prolonged exposure to high noise levels can cause permanent hearing damage and increase the risk of accidents by masking warning signals. Employers have a legal responsibility to monitor noise and take action when levels exceed safe limits. Measuring noise helps to:
Identify areas with harmful noise exposure
Ensure compliance with occupational safety standards
Implement effective noise control measures
Protect employee hearing and overall health
Reduce liability and workers’ compensation claims
Improve workplace communication and productivity
Without accurate noise measurements, it is impossible to know where risks exist or how well noise reduction efforts are working.
Choosing the Right Equipment
Two main tools are used to measure workplace noise:
Sound Level Meter (SLM): Measures noise at a specific moment or over a short period. Ideal for spot checks and identifying noisy equipment or areas.
Noise Dosimeter: Worn by employees to record noise exposure over an entire shift. Provides a time-weighted average (TWA) and peak noise levels.
Both devices must be calibrated regularly to ensure accurate readings. Calibration involves adjusting the device using a known sound source before and after measurements.
How to Take Accurate Noise Measurements
Positioning the Device
Place the sound level meter or dosimeter at ear height, about 1.5 meters (5 feet) above the floor, to simulate the employee’s hearing zone. Avoid placing the device too close to walls or reflective surfaces that can distort readings.
Selecting Measurement Locations
Focus on areas where employees spend the most time, such as workstations, assembly lines, or control rooms. Measure near noisy machinery, ventilation systems, or other noise sources.
Timing and Conditions
Noise levels can vary throughout the day depending on operations. Take measurements during different shifts and operational conditions to capture fluctuations. For example:
During peak production hours
When specific machines are running
During maintenance or cleaning activities
Recording Key Metrics
Capture these important noise metrics:
Decibel (dB) levels: Instantaneous sound pressure level
Time-weighted average (TWA): Average noise exposure over a work shift, usually 8 hours
Peak noise exposure: Highest noise level during the measurement period
These metrics help assess the risk and determine if noise control measures are needed.
Comparing Results to Safety Standards
Occupational safety agencies set limits for noise exposure to protect workers. For example, the U.S. Occupational Safety and Health Administration (OSHA) sets the permissible exposure limit (PEL) at 90 dB over 8 hours, while the National Institute for Occupational Safety and Health (NIOSH) recommends a lower limit of 85 dB.
Compare your measurements to these standards:
If TWA exceeds the limit, noise controls or hearing protection are required.
Peak noise levels above 140 dB may require immediate action to prevent hearing damage.
Repeated exposure to noise above 85 dB can cause hearing loss over time.
Implementing Noise Control Measures
Once you identify high noise areas, take steps to reduce exposure:
Engineering controls: Install barriers, enclosures, or sound-absorbing materials around noisy equipment.
Administrative controls: Rotate workers to limit time spent in noisy areas or schedule noisy tasks when fewer employees are present.
Personal protective equipment: Provide hearing protection devices such as earplugs or earmuffs.
Regular noise monitoring ensures these measures remain effective and helps detect new noise hazards.
Best Practices for Ongoing Noise Monitoring
Conduct noise assessments at least annually or whenever workplace conditions change.
Train employees on the importance of noise monitoring and proper use of hearing protection.
Keep detailed records of noise measurements and control actions.
Use data to improve workplace design and equipment selection.
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