Noise-induced hearing loss: time to make it personal?

In the past, I’ve written about my disappointment that NIHL was not included in HSE’s post-implementation review of the Reporting of Injuries, Diseases and Dangerous Occurrences Regulations 2013 (RIDDOR) reporting legislation.²

Photograph: iStock/miniseries

HSE was considering whether the list of occupational diseases affecting workers that must be reported to HSE by employers under RIDDOR should be expanded, but NIHL was not considered for inclusion in the list of reportable diseases at that time. So, perhaps as a quid pro quo (although that’s pure speculation on my part), HSE announced in the spring of 2024 that it was going to carry out a multi-year campaign of targeted inspections focusing on high noise sectors, aimed at finding out (among other things):

• What type of hearing protection equipment (HPE) is being used?
• Is training on how to fit being given?
• Are wear rates being maintained?
• Is a selection of HPE being supplied?
• Is the HPE correctly specified?
• Is the HPE being maintained?

The planned inspections are still ongoing and while a report is not yet available, interim findings were presented at the UK Hearing Conservation Association’s (UKHCA) annual conference in November 2024 and summarised in an article by the British Irish Hearing Instrument Manufacturers Association (BIHIMA)⁹.

Inspectors had interacted with more than 5,000 duty holders, in sectors such as manufacturing, construction, food, horticulture and agriculture. BIHMA reported that after many years of different campaigns aimed at raising awareness of the need for adequate hearing protection at work, the initial results are surprising. Around 40 per cent of the fixed workplaces visited had noise levels above the upper exposure action value specified in the Control of Noise at Work Regulations. For these workshops and factories, hearing protection is mandatory and means health surveillance is a must-have and not an optional extra. However, I will explain more about health surveillance later.

Chris Steel, HSE specialist inspector and a driving force behind the campaign, was reported as saying: “The fact that industry is noisy is hardly a shock – what we wanted to uncover was whether it was being dealt with correctly. Worryingly, we had to issue just under half of all the sites we visited with formal enforcement. This meant that HSE inspectors had to put pen to paper and ask employers to take action to reduce their noise risk.” According to the BIHIMA news report, this represents a 300 per cent uplift in noise-related enforcement letters and notices.

Commenting further on whether workers were aware of how to effectively use and care for hearing protection, Steel added: “One of our big questions was whether employers were ensuring their workers were well trained in the use of earmuffs and ear plugs. Did they know how to use hearing protection, how to care for it and what the warning signs were of hearing damage? These are all important questions that all employers should be asking themselves for the safety of their staff.”

When workers were asked if they knew how to care for their hearing protection:

• 77 per cent said they had not been shown how to store it
• 81 per cent said they had not been shown how to check its condition
• 74 per cent said they would not know how to report damage.

In addition, 63 per cent of workers were not told how important it is to wear hearing protection all the time they are in a noisy area. However, the biggest worry is that only five per cent of employers had checked to see if their workers could hear warning signals while wearing hearing protection; so-called overprotection.

The BIHIMA further commented that as far back as 1972, even before HSE existed, the government line on the use of hearing protection was that it should be seen as a temporary measure until noise controls can be put in place.  Half a century later and inspectors found that hearing protection is sometimes the only control measure on-site, and it remains the case that from a hierarchy of controls perspective, personal protective equipment (PPE) is considered the least effective control method, requiring the most supervision.

Indeed, this itself was made clear in a 2009 HSE research report⁴ that found a quarter of companies monitored during on-site observation of hearing protector use during normal working, and one in four groups of outdoor worker teams monitored using hearing protection, were found to be using the protection in an ineffective way likely to result in negligible or zero protection for the majority of these workers. Also, in premises where the majority of workers were actually seen making effective use of hearing protection, one in seven workers were still seen to be not using hearing protection when and where its use was required.

HSE concluded that overall, this suggests only 60 per cent of workers expected to be using hearing protection are in fact receiving any protection.  

What’s Einstein’s definition of insanity? Do the same things and expect a different result!

It’s coincidental then that there is a revision to the British Standard on selection, use, care and maintenance of hearing protection (BS EN 458)⁵ which is in the final throes of approval, having recently been put out to public consultation.

A few of the key changes/clarifications include:

• Passive attenuation data should only be used for dual protection (important since there is no relevant EN352 test standard covering this and HSE’s key Noise Guidance L108 simply says “get some data”).
• The expectation that dual protection will provide ‘up to 6dB’ in addition to the higher rated protector has been removed. A note has been added instead to explain that the improvement may be as little as 1dB or up to 12dB above the higher SNR.
• Annex B on impulsive noise now includes the noise types in terms of a ‘C-A’ measurement (LCFmax – LAFmax), but has been reduced to two discrete categories

The use of hearing protection fit testing is also mentioned in the consultation on the revised standard. This is something the UK Hearing Conservation Association⁶ has called to be adopted across industry, in the same way it is mandatory for respiratory protection featuring tight-fitting facepieces to be individually fit tested for each user. The UK’s Ministry of Defence is believed to be investigating this requirement, after individual fit testing for hearing protection for armed forces personnel was recommended several years ago in a Defence Science and Technology Laboratory report⁷ by Rachel van Besouw, who is now employed by HSE and is chair of the BSI committee that has worked on the BS EN 458 revision.

Photograph: iStock/GCShutter

Normally the UK is ahead of the regulatory curve on occupational health and safety, particularly when it comes to noise, but for once we seem to be lagging the US, since both the US Department of Defense⁸ and NIOSH (National Institute for Occupational Safety and Health)⁹ have made ‘landmark’ recommendations for individual fit testing for hearing protection.

Health surveillance

Health surveillance is a form of workplace screening that aims to identify early signs of NIHL (a characteristic dip in the audiogram at 4KHz) and it usually consists of a symptom questionnaire followed by screening audiometry, undertaken at regular intervals. Hot-off-the press guidance on how to conduct health surveillance has been jointly published by the Society of Occupational Medicine and UKHCA.¹º

In 2021, HSE revised its noise guidance document L108, including clarifying the health surveillance advice for health professionals in Table 12, where a new column was added regarding review for ‘NIHL seen on audiogram?’ Paragraph 24 of the guidance goes on to make clear that an initial step will be for the audiogram to be assessed for the presence of NIHL. Another update relates to referral requirements; where NIHL is newly identified or progressive, the worker should be placed in Category 3 and be referred for medical assessment by an appropriately trained doctor – for example, an occupational physician.

Health Wizard is one such supplier of workplace audiometric screening and has provided the following data and comment. Based on the several thousand tests they have conducted, empirical data indicates that more than 25 per cent of patients had never had a hearing test at work before (this question is asked as part of the pre-test questionnaire), which supports the need for more accessible testing and greater recognition of hearing surveillance.

Nearly four in 10 of the hearing tests conducted by Health Wizard indicated a unilateral or bilateral hearing loss of at least 35dB. Medically, this is an (upper) mild hearing loss: depending on age or NIHL assessment, the HSE guidelines often consider this to be ‘normal’. However, ALL patients with this level of hearing loss are likely to be experiencing some of the effects of hearing loss that contribute to negative wellbeing and safety in the workplace, whether they are aware of it or not.

For example, they may be experiencing communication frustrations, fatigue due to coping strategies, challenges in social situations and potentially even reduced site safety. From this perspective, a clear understanding of your hearing abilities is the first step to taking responsibility for your hearing health.

Considering the use of hearing protection equipment at work, Health Wizard’s questionnaires suggest that only marginally less than 40 per cent of staff working in noisy environments and 36 per cent of staff who had been exposed to loud noise in the previous 48 hours at work had received training in the selection and correct use of hearing protection in the last 12 months. This suggests that in an era of ever smarter hearing protection and more HPE options, the best protection is still only as good as how it is selected, used, cared for and maintained (as per the BS EN 458 standard).

Smart PPE and wearable technology

I’ve been a long-time supporter of instrumentation for noise measurement – i.e. sound level meters and noise dosimeters, together with an all-important acoustic (field) calibrator, such as that from Casella, which conform to International Standards (and are capable of being independently verified). Indeed, the above mentioned HSE L108 guidance states that noise measurement instrumentation should conform to International Standards if it is used as part of an objective risk assessment!

However, I’ve become increasingly supportive of smart PPE solutions such as Smart Alert from Minuendo, which are capable of monitoring noise levels both inside and outside the hearing protector. My caveat here is that such systems do not currently comply with relevant standards – although they may be ‘designed to meet’ the standards at least as far as the electronics are concerned. However, most importantly, they can provide indicative noise data at scale, in near real time, allowing for actionable insights. It also interfaces to Reactec’s R-Link wrist-worn system and cloud-based platform that can monitor a plethora of other health & safety related risks including proximity (to vehicles and machinery) and hand-arm vibration exposure.

So, what of the future as I inexorably face eventual retirement? I really feel that the tide is turning on NIHL and that it will be technology solutions that will change the status quo. Who knows where we will be in another 50 years!

Neal Hill is an independent marketing and product management consultant with over 40 years’ experience in noise measurement and hearing protection. He sits on the BSI PH/7 hearing protection standards committee as the UKHCA’s nominated representative. Contact him at:

linkedin.com/in/neal-hill-89b16211/

References

1. britsafe.org/safety-management/2024/why-we-need-to-harness-new-technology-to-prevent-noise-induced-hearing-loss
2. The UK RIDDOR Riddle
3. Workplace Noise Intervention project highlights significant room for improvement - BIHIMA
4. HSE Research Report, RR720 (2009) Real world use and performance of hearing protection
5. BS EN 458 Hearing protectors. Recommendations for selection, use, care and maintenance. Guidance document
6. UKHCA Hearing Protection Fit Testing — An Introductory Guide | Hearing Conservation
7. Human factors assessment of armoured fighting vehicle headset function Contemporary Ergonomics and Human Factors 2019. R. M. van Besouw, Dstl, Porton Down, Salisbury, UK
8. Department of Defense Instruction 6055.12 Hearing Conservation Program, Nov 2023
9. NIOSH science policy update: individual fit-testing recommendation for hearing protection devices | NIOSH | CDC
10. Supplementary Guidance on Interpreting an Audiogram for Indications of Occupational Noise-Induced Hearing Loss (NIHL). Joint SOM & UKHCA publication.