The Critical Role of Noise Source Investigation

Noise in the workplace is more than just an annoyance; it is a pollutant with the power to disrupt operations, damage hearing, and strain working relationships. While the legal duty to manage noise risk is clear, many businesses find that taking only a few measurements is insufficient.

The true challenge lies not in recording the symptom, but in locating the source. This is where a detailed Noise Source Investigation becomes an indispensable tool. At PDA Ltd, we specialise in finding these hidden acoustic culprits, ensuring you can proactively and permanently resolve your workplace noise issues.

A Deeper Look at Noise Risk

The Health and Safety Executive (HSE) states that a noise risk assessment is a comprehensive process designed to protect employees and meet legal obligations as required by the Control of Noise at Work Regulations 2005. A professional evaluation should first identify where noise risks exist and who will most likely be affected.

This involves carefully considering work processes, task variations, and the potential for cumulative exposure. It requires a reliable estimate of employee exposure, which must be representative of their work over a period and take into account how it might vary from day to day.

Once risks are identified, the assessment guides the necessary actions. These would include the implementing engineering controls and noise-control measures and the provision of hearing protection where other sound-mitigating solutions are not reasonably practicable.

The assessment will also flag which employees may require health surveillance due to exposure. A documented action plan with responsibilities and a clear timetable is essential for compliance. This is a living document that requires regular review, especially if circumstances in the workplace change.

This foundational approach is crucial at PDA, but it is often just the beginning of the journey to a quieter, safer environment. When complaints arise from outside the workplace, the investigation must go further.

Case in Point: A Quiet Resolution at a Cheese Creamery

A recent project for a creamery in the Northwest of England perfectly illustrates the value of a comprehensive Noise Source Investigation. Residents living near the 24/7 facility had raised concerns about a persistent, “tinny” noise at night, causing significant sleep disturbance.  The client needed to understand the source and its impact quickly.

PDA Ltd was commissioned to conduct a detailed investigation. Our team deployed long-term ambient noise monitors near the site boundary and at key residential receptors. We also measured individual plant items and compared predicted noise levels from a recently installed plant against baseline levels.

Using SoundPLAN sound modelling software, our analysis revealed a significant finding: a 9-13 dB increase in noise levels at the nearest noise-sensitive receptors. This clearly indicated that a new plant—specifically, an SPX unit and diesel refrigeration trailers—was the cause.

The assessment determined that this increase would likely exceed the nighttime noise criteria of BS8233, creating a potential for nuisance. We didn’t just identify the problem; we provided a clear path to resolution. PDA recommended two targeted mitigation measures: replacing a high-level louvre with an acoustic version offering a sound reduction of at least 16 dB, and switching the diesel refrigeration trailers to electric plug-in units when stationary.

The outcome was a resounding success. Our acoustic modelling demonstrated that with these measures in place, the overall noise level at the worst-case receptor would see a negligible 3 dB increase compared to the previous operational baseline. This level of change is barely imperceptible to the human ear and is highly unlikely to trigger further complaints.

PDA’s involvement was instrumental. By combining meticulous measurement, predictive modelling, and a collaborative approach with the client’s engineering teams, we provided a practical and cost-effective solution that integrated seamlessly with their operations. We helped a major food producer safeguard its ongoing business, maintain excellent community relations, and ensure a quieter environment for all.

Our Collaborative Approach

At PDA Ltd, we pride ourselves on finding a workable solution. We believe that effective Noise Source Investigation is about understanding each site’s unique operational context and working together to find a resolution that works for everyone.

From initial assessment to final outcome, we aim to clarify, ensure compliance, and deliver a quieter world for your business and its neighbours. Contact us today to learn how we can help you with our professional noise source investigation services.