Noise-induced hearing loss remains one of the most common occupational health issues in the UK, yet it is entirely preventable. Excessive noise does not just cause permanent hearing damage; it creates safety risks by masking warning signals and contributes to workplace stress. For business owners and health and safety managers, understanding the acoustic environment is not just good practice. It is a fundamental requirement to protect the workforce.
The first step in managing these risks is conducting a noise survey. This assessment provides the data needed to make informed decisions about protecting employees. Without accurate measurements, any control measures you implement are merely guesswork. This guide outlines how to approach a noise survey to verify compliance with regulations and create a safer working environment.
Understanding Noise Surveys
A noise survey systematically measures workplace sound levels to assess employee noise exposure and pinpoint machinery or processes causing hazardous noise. Its primary goal is to ensure compliance with the Control of Noise at Work Regulations 2005, which set action levels at 80 dB and 85 dB, requiring employers to protect hearing.
The survey identifies at-risk employees, areas needing hearing protection, and where engineering controls are necessary. Accurate, legally defensible results require calibrated equipment and a structured methodology—a smartphone app won’t suffice.
Preparing for an Accurate Survey
A competent, trained individual must conduct the survey. If in-house expertise is lacking, hiring an external consultant is advisable. Ensure the equipment, typically a Class 1 or Class 2 integrating sound level meter, is properly calibrated and suited to your industrial environment.
Plan the survey timing carefully to capture representative working conditions. Avoid measuring during lunch breaks or downtime, as this skews results. Conduct measurements during normal or peak operations, potentially over multiple days or shifts, to ensure accurate exposure data.
Measuring Sound Levels Effectively
The measurement phase involves collecting data that reflects workers’ actual experiences. For static workers at a single machine, measure noise at ear level (preferably without the person present or alongside them). For mobile workers like maintenance staff or forklift drivers, personal noise dosimeters worn on the shoulder throughout the shift provide a more accurate calculation of daily noise exposure (LEP,d) than sound level meters.
Capture both the average noise level over time (LAeq) and peak sound pressures (LCpeak) from impact noises like hammering or pneumatic exhausts. Always document the context of each measurement. Instead of noting that a machine is “loud,” specify what the machine was doing, how long it was used, and the production rate. This context is essential for identifying ways to reduce noise exposure.
Analyzing the Data
Once the physical survey is complete, the data requires careful analysis. You must compare the measured levels against the lower and upper exposure action values defined in the regulations. This analysis will highlight where immediate action is required. For instance, if daily exposure exceeds 85 dB, you must implement a programme of technical and organizational measures to reduce exposure, rather than relying solely on hearing protection.
The analysis should also look for patterns. Is a specific compressor causing high noise levels across an entire zone? Is a particular process significantly louder than others? This insight allows you to target your resources effectively. It moves you from knowing you have a noise problem to understanding exactly what causes it and how to fix it.
Implementing Noise Control Measures
The survey’s goal is to reduce risk, not just document it. When you identify high noise levels, you should follow the hierarchy of controls. The most effective method is elimination or substitution, such as replacing a loud machine with a quieter one. If that isn’t feasible, the next step is engineering controls, like fitting silencers, using acoustic enclosures, or adding damping material.
Administrative controls, such as changing shift patterns to limit an individual’s time in a high-noise area, also reduce exposure. Personal Protective Equipment (PPE) like ear defenders or plugs should only be used as a last resort after exhausting all other measures, as it can fail or be worn incorrectly. If PPE is required, the survey data will specify the level of attenuation needed to bring noise to a safe level.
Maintaining a Safe Environment
A noise survey is not a one-time event. Workplaces change. New machinery is installed, old machines wear out and become noisier, and shift patterns shift. Regular assessments verify that your control measures remain effective and that your employees remain protected. By taking a proactive approach to noise management, you meet your legal obligations and demonstrate a genuine commitment to the long-term health of your team.