Keep the noise down

Despite the dangers of exposure to immoderate noise levels at work being well documented, noise induced hearing loss remains a problem. Measuring noise levels in the workplace and finding effective solutions for reducing these levels at the source is the most effective way to prevent workers being exposed to potentially dangerous noise levels.

To combat the problem, the Control of Noise at Work Regulations 2005 – which came into force in April 2006 – introduced stiffer control requirements. The new regulations reduced upper and lower action levels by 5dB from 90 and 85dB(A) in the previous directive to 85 and 80dB(A) and introduced a new exposure limit of 87dB(A).

Noise-induced hearing loss is irreversible but entirely preventable. While the focus of earlier legislation was on assessment, quantification of exposure levels and consequent hearing protection, the latest regulations focus on controlling noise at source and the implication and monitoring of a noise control action plan over a given period of time.

This most recent legislation also requires that where possible noise should be controlled at source, removing the need for over-reliance on PPE, which should only be used when other forms of control have been exhausted.

Understanding the problem

The key to practical and cost-effective treatment of noise problems is to start with an accurate diagnosis of the noise source. You need to identify and then treat the dominant source. This is best achieved by taking a range of sound readings at various frequencies and turning off machinery to attempt to identify and isolate dominant noise sources.

Organisations that are affected by high noise levels from machinery are much more likely to require a full noise audit and the involvement of more specialist noise control expertise – such as those provided by Wakefield Acoustics.

An effective noise control audit, undertaken as part of an overall noise control action plan, can identify the benefits in terms of noise control options and the potential costs involved. 

Isolation

Where it is possible to isolate noisy machinery, the erection of enclosures, screens and baffles should be considered. An alternative would be to install sound booths. 

As a direct result of legislation, many manufacturing companies previously not affected by the regulations have noise levels that are just above the upper action levels of 85dB(A) daily exposure levels. It is these companies who are most likely to benefit from a consultation with a noise control engineer. However with the increased trend in claims for industrial hearing loss, it is sensible for all companies that have a potential for employees to be exposed to noise levels in excess of 80dB(A) to carry out regular audits and keep detailed records of all noise mitigation measure undertaken.

Practical solutions

Whilst reductions in noise levels can be achieved by thorough examination, consideration of practical solutions, engineering controls and isolation, inevitably – and despite undertaking these actions – situations will arise that require the use of noise control products.

This will often result in workers being protected from potentially hazardous noise levels in the workplace, and the harmful effects they can cause, by adopting the strategy of separation. This requires the use of noise control products such as acoustic enclosures, sound havens, screens and barriers, which isolate ‘the receiver’ from the noise source. 

A further example of industrial noise can be environmental noise pollution. This employs the use of BS4142 to assess the levels being experienced. Solutions can often include acoustic screens to site boundaries to prevent noise contamination to the local area. 

When attempting to address the above noise issues, it is important that specialists are consulted to assist with the analysis, diagnosis and provision of noise control measures.

Wakefield Acoustics offers a Total Acoustics Responsibility Service – from measurement and assessment to product manufacture, installation and commissioning and is able to engineer practical and cost effective solutions for most industrial and environmental noise problems, thereby helping customers to comply with increasingly stringent industrial and environmental noise legislation.