NOISE ASSESSMENT AT WORK
Hearing protection
Over-protection: issues with too-strong hearing protection
Hearing protection can be too strong as well as too weak
Often leads to decreased compliance, increased risk and wasted money
“Thank you for the report. Very comprehensive with good, easy to understand information for us to make improvements
and changes where necessary”. QHSE Manager, Hull, 2022
Hearing protection can be too powerful as well as too weak
Over-protection means the hearing protection is too strong for the noise risk present and is reducing the noise levels too much. This is considered to be a problem as it can lead to unintended consequences.
An important principle in hearing protection is that higher SNR is not synonymous with ‘better’ hearing protection.
A common mistake well-meaning companies make is to assume that the more noise a hearing protector removes the better, so they buy the strongest they can. However, hearing protection needs to be chosen which is matched to the noise risk, not purely on ‘most powerful is better’.
Remember, we are talking about being at work here - if you want to isolate yourself at home or gardening or doing DIY then absolutely fine.
What is the risk with over protection?
it’s not a ‘risk’ in the same way that too little protection is, but there are still problems, for example:
The protector is so powerful it reduces volumes well below conversational levels so people simply don’t use it. Hearing protection which is too strong makes people more likely to not wear it at all.
Others will kind of use it, but will take the hearing protection off to talk to others in their workplace, giving significant cumulative periods with no protection. Just a cumulative 15 minutes a day with no hearing protection in a noise of 100 dB(A) will mean hitting the 85 dB(A) average where hearing is at risk.
Most likely though is that they will deliberately not put ear plugs in properly in the first place to keep them ‘loose’ and keep the noise levels higher. This is very common to see.
Over-protection can also mean people have issues hearing machine alarms, forklifts, etc. which can cause secondary issues for both production and safety.
Over protection can increase danger for some people such as forklift truck drivers. There is no exemption for forklift drivers from the need to wear hearing protection, but they need to have the right hearing protection - enough to remove the danger but not so much it isolates them.
Employers spend a lot on this stuff. Say you have a disposable ear plug which costs 8p - that’s properly cheap and at the lower end of the price range. As it is disposable people use a couple of pairs a day. That equates to something like £38 per employee per year, nearly £4,000 a year if you have 100 employees. Granted, for a company with 100 employees, £4,000 is not a lot of money, but because the protector is too strong and they are taking them out or leaving them loose, you are getting pretty much zero benefit. It is just wasting money.
Most of these mean that the employer has a double whammy - the too-powerful hearing protection has actually increased risks via reduced compliance with wearing it, and they are spending a lot of money for very little benefit to boot.
Don’t forget employers: issuing hearing protection and telling people to wear it is not enough to have met your legal duties, you have to monitor and supervise and enforce correct use and too-powerful protection makes that a lot harder. Hearing protection which is too strong means employers probably have increased liability as well as the risks to the individual.
What counts as over-protection?
There is no definite figure which counts as ‘over protection’ and what is defined as over-protection can vary. In our risk assessments we define it as below about 65 dB. This is actually very quiet but it is the typical level of a quiet office or someone’s house and seems to be a reasonable noise level to let someone work at every day. Others sometimes define it as 70dB and up - that is where the regulatory body in the UK, the HSE, often consider it. Personally, we go on 65dB and up as that’s a normal non-noisy working environment.
A ‘perfect’ level under the hearing protection is about 72-75 dB(A).
Hearing protection being marketed as high noise reduction / high attenuation
Some hearing protection manufacturers market hearing protection as having high noise reductions - they shout about levels of attenuation of 38 or 39dB (about as high as you can go) in their marketing. But pretty much no workplace actually needs this level of protection, and for most workplaces that much protection actually introduces risks and problems. Manufacturers market protectors with this much noise reduction often for two reasons:
They don’t understand the market they are selling into. It sounds silly but there are some manufacturers out there who haven’t got a clue about noise in workplaces, or management of noise risks. They see a gap in the market to sell something and make a product but have a rather shallow knowledge of what they are selling. A give-away of this is the myriad sellers you see marketing something in the UK using the American NRR in their marketing - NRR has no relevance here and is a sign they are more into marketing than depth of knowledge on hearing protection.
And that ties into the second issue - the purchaser’s common belief that higher protection is better. Purchasing Departments often know nothing about what they are buying, ‘it’s just ear plugs’ so look at price and strength and that’s it. Where there is a demand, manufacturer’s will supply a product, whether or not that demand is actually valid.
What should the employer do?
Firstly, assess your hearing protection’s performance levels. Then, if you have protectors which are over-protecting for all your noise risks, move to one which is a bit less meaty.
If you have a mixed noise risk so have some jobs where the protector is too much, but others where it is about right, check that people working in the over-protected area can still hear things like forklifts and alarms, and if so then live with it. It is better to over-protect than under-protect - the chances of damaging anyone’s hearing with over-protection are present, but are much less than with under-protection.