Achieving adequate protection
September 1st 2009

In scenarios where hearing protection is required,providing adequate protection is only half the battle; ensuring a correct fit is also essential - and not as easy as it looks, discovers Georgina Bisby when trying out a new technology at Sperian's headquaters.

Since the introduction of the Control of Noise at Work Regulations 2005 which came into force for most workplaces in April 2006 and for the music and entertainment sectors in April 2008, there has been growing awareness about the importance of hearing protection.

As with most forms of PPE, hearing protection is rarely advised as the first or only solution where a noise risk is concerned. Other working methods such as reducing exposure to noise through the choice of work equipment should be considered first. But when hearing protection is required there is now a huge variety of earplug models on the market; the desire for comfort is continuing to drive innovation while, to meet the demands of the entertainment sector style has become a more significant consideration.

However, awareness of new regulations and a wide availability of protective products doesn't ensure adequate hearing protection. The effectiveness of hearing protection is normally assessed in a laboratory environment, but there are questions over how this translates in the working environment. A recent research report from the HSE, RR720 – Real world use and performance of hearing protection, suggests that hearing protection should never be seen as a simple or reliable solution.

Although hearing protection is supplied with a Single Number Rating (SNR) system indicating the noise levels it can be used to protect against, this is only a theoretical level of hearing protection as opposed to an actual measurement. The actual measurement depends on how well the protection is fitted which is likely to depend on how well someone has been trained and supported in the use of their hearing protection. The HSE's report found that compressible foam earplugs are generally poorly fitted as users are often unaware of how these should be rolled down before fitting, or are unaware of the importance of doing this.

Incorrectly inserted earplugs may give virtually no attenuation.

VeriPRO is a new technology from Howard Leight by Sperian which measures real-world attenuation of unmodified earplugs. Using a loudness balancing technique to determine the effectiveness of an employee's earplug over a range of frequencies VeriPRO gives a Personal Attenuation Rating (PAR), which identifies the actual protection an employee receives from his or her earplug in each ear. VeriPRO can be used with any earplug, and the tests performed in virtually any setting.

When trying out the VeriPRO system I initially had significant problems inserting the earplugs adequately. As an irregular user of ear protection, it took several attempts to compress the foam earplug enough to be able to insert it the required distance into my ear. I was also naturally cautious about inserting the plug too far.

The test revealed that even when I had mastered the insertion, in the case of one of my ears I have an unusual shaped ear canal and would need to try out several models of hearing protection before I find one that suits me, possibly needing to use a different model in each ear.

My experience immediately illustrated how personal an issue hearing protection is and how challenging it can be to fit correctly. The reassuring news is that once identified problems aren't generally too hard to solve - the short training videos included with the VeriPRO system is said to usually be enough to overcome any problems in achieving expected protection.

David Leonard of Sperian Protection summarises the key points to think about when inserting ear protection: "Opening the ear canal is most important in order to get a good fit both with reusable and disposable earplugs. The challenge is that most ear canals are not straight but bent, some back some forward and even up or down. It is necessary to get the earplug well into the ear canal and this is done by the wearer reaching behind the head with the hand opposite the ear that is being fitted and pulling outwards and upwards on the Pinna while inserting the earplug.

"A correctly fitted disposable earplug (foam) should not be visible in the ear when looking straight at the wearer, and for a reusable, only the stem should be visible with the 'body' of the earplug well inside the ear canal."

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