A Fitting Time to Consider the Effectiveness of Hearing Protection.

Feb 16, 2022 | 0 comments

If you were one of the 11+ million viewers watching the BBC’s, Strictly Come Dancing final you will have seen winner, actor Rose Ayling-Ellis, reprise her ground-breaking dance, when the music was paused midway through the performance for viewers to experience what it is like for her as a profoundly deaf person. Powerful stuff. It has been said that Rose has championed awareness for and change the attitudes towards deafness in the UK and she has now gone on to the Strictly Tour which will have changed her life and career for ever. Many are not so fortunate.

The Oscar winning 2021 film, The Sound of Metal has also been credited with creating awareness. It follows Ruben, the drummer of a two-piece band as he navigates tinnitus, which is evolving into permanent hearing loss. There are of course many real-life musicians like Phil Collins who have tinnitus and/or hearing loss due to loud music. The fact is that – whatever its source – noise damages hearing.

Protect to Save

Indeed, for millions of workers globally, noise induced hearing loss (NIHL) from exposure to loud noise, has remained an endemic issue for decades. Frustratingly, it is avoidable and despite a multi-billion-dollar hearing protection industry, in terms of the hierarchy of controls, hearing protection is considered the least effective method requiring the most supervision – this is not because stopping noise is not effective at saving hearing, but due to human factors.

Indeed, the UK Health and Safety Executive (HSE) went as far as to say that for many workers, hearing protection provides no protection whatsoever [1]. Even the best performing protector quickly becomes ineffective if not worn 100% of the time worn whilst in noise – as demonstrated in figure 1. This clearly shows how hearing protection worn as much as 95% of the time only provides ½ the protection as if it was worn those vital extra minutes that make 100%. It’s great to see this informative graphic has been usefully added to the latest revision of HSE Guidance, publication L108 [2].

HSE L108 chart demonstrates how just a few minutes without hearing protection will halve the protection it gives

Figure 1. Source L108, Guidance on the Control of Noise at Work Regulations.

These figures also assume that the hearing protector is well-maintained and correctly fitted in the first place. Once again, this differs from reality, if the hearing protection confiscated by the HSE in figure 2 is anything to go by!

Damaged hearing protection found in use by the HSE

Figure 2. Courtesy of Chris Steel, Specialist Inspector, HSE.

 

The Gold Standard

These potential short comings (in hearing protection) may well serve to mask the problem, and the first signs of hearing loss are often not noticed by the individual; family members tend to be the first to notice signs such as having the radio or TV turned up too loud, or children having difficulty being heard. So, by the time damage has been diagnosed (often as a characteristic ‘notch’ in an audiogram) the irreversible damage has already been done. It used to be the case in the 1970s and 80s, when large employers like GKN and Lucas, conducted routine hearing tests, although attitudes to noise and hearing protection were typically “don’t worry son, you’ll get used to it (the noise)”. This is according to the recollection of the author, who as a 17-year-old engineering apprentice in 1975 had their hearing tested as early-employment best practice. After 50 years, audiometry remains the gold standard for health surveillance, enshrined in part 5 of L108. And to this day, a hearing test at induction is still best practice in occupational health.

This makes sense when you think that you’re not going to know how someone’s hearing has changed if you don’t know whether it was any good in the first place. Alternative field methods are being considered but as Hitchhiker’s author Douglas Adams said, “new technology is stuff that doesn’t work yet”.

The recently founded Hearing Conservation Association (UKHCA) is championing ‘the cause’ and has published new guidance on fit testing [3]. They believe that fit testing is a useful assurance methodology that could be added to an employer’s hearing conservation programme (HCP) to give the user and their employer the opportunity to measure how much attenuation their individual protection actually delivers.

The good news is that if you know where to look and who to ask, technology exists to make both screening audiometry a simple and affordable task backed by expert oversight – as required by the Guidance – as well as being an ideal platform to implement the proposed fit testing [4].

In summary, a ‘belt and braces’ approach to noise management is strongly advised to include fit testing and routine, screening audiometry. And – to reiterate the point – people exposed to noise at work must be provided with a hearing test by law. Audiometric testing is established as best practice and is now easier than ever. Hearing loss is progressive and cannot be reversed as Ruben discovered in the Film. His life was in freefall and at the end of the film, sitting in a park with the ringing of a church bell distorted by his implants, Ruben removes his processors and sits, in silence.

References

  1. HSE research report, RR720.
  2. Guidance on the Control of Noise at Work Regulations, HSE Publication L108
  3. UKHCA Hearing Protection Fit Testing — An Introductory Guide | Hearing Conservation
  4. BS EN 17479 Hearing Protection – Guidance on selection of individual fit testing methods