Making a noise about industrial deafness

Claims for noise induced hearing loss (NIHL) have increased to a record high in recent years, with an estimated 18,000 new cases reported each year in the UK alone. In fact, recent research from HSE reveals some 170,000 people suffer from hearing damage due to excessive noise in the workplace.

Even though the highest rates of NIHL occur in manufacturing, energy and extraction and construction, it is an injury that affects people in a number of industries. Noise induced hearing loss, caused by prolonged exposure to excessive noise levels, can cause a wide range of long term and often-irreversible health impacts including permanent hearing loss, tinnitus, cardiovascular diseases, sleep disturbance, stress, brain impairment and mental health issues.

Excessive noise levels are not only harmful to the health of workers, but can also lead to lower productivity levels, with a requirement for increased staffing to cover for absenteeism, or shorter hours of operation, which in turn can effect business levels.

Faced with such business and health impacts, an increasing number of companies, across a range of sectors, are placing a greater emphasis on noise control measures. In fact most industries are now proactively addressing noise issues during the design, and construction of their facilities, such that noise control measures are considered from the outset.

The key to practical and cost-effectively treating noise problems is to begin with an accurate identification of the noise source or sources. Initially you need to recognise and treat the dominant noise 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.

Companies that are affected by excessive noise levels from machinery are much more likely to require a complete noise audit and the involvement of more specialist noise control expertise.

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

As a direct result of legislation changes, many companies previously not affected by the regulations have noise levels that are above the upper action levels of 85 dB (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 losses it is sensible for all companies that have a potential for employees being exposed to noise levels in excess of 80 dB (A) to carry out regular audits and keep detailed records of all noise mitigation measure undertaken.

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

Positioning noisy machinery in less prominent areas, meaning workers are less likely to be exposed to potentially harmful noise levels, can help reduce the risks inherent with prolonged exposure. While improved working practices, adjusting working patterns to limit lengthy exposure and implementing a low-noise machinery policy can also reduce risk. Nevertheless, with the use of loud machinery in many industries, it is not often possible to take this action and as such other noise control measures have to be put into action.

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

Acoustic enclosures, sounds havens, screens and barriers can be used to isolate ‘the receiver’ from the dominant noise source  – a strategy known as separation.

Noise control solutions such as acoustic enclosures and screens are fully bespoke, meaning they can be individually adapted for different industries and applications, in order to address specific noise problems. Dependent on noise specification, customer application, access and structural requirements, several types of enclosure are offered. From modular panel to panel bolted constructions, intermediate panels mounted in a bolted frameworked or one-piece drop over units choosing the correct product can be difficult.

In certain circumstances it is not always feasible to treat noise at source, particularly in environments where there are multiple noise sources contributing to the overall exposure experienced by operators. In such cases, noise havens can be installed which are designed to offer respite for operators in noisy environments.

Designs must not only consider the inherent noise of equipment and the desired maximum noise levels required in different areas, but also the logistical and spatial limitations in terms of access to, from and around the facility. Therefore the correct design and selection of acoustic products in particular housings for plant items is essential. This must be achieved first time to avoid the serious implications of non-compliance of specifications and the excessively costly nature of retro fitting. There is no margin for error and with this in mind Wakefield Acoustics have tested the performance of their range of acoustic enclosures to BS EN ISO 11546-1:2009, as required by BS EN ISO 15667 ‘Acoustics – guidelines for noise control by enclosures and cabins’.

Being able to identify and resolve noise issues in the workplace is increasingly becoming a necessity, rather than an afterthought, for businesses across a range of sectors. As a result, companies must now begin to implement noise control measures across their facilities, not only to meet stringent legislation but also to protect the welfare of their workforce.