HOW TO CHOOSE AND USE THE RIGHT HEARING PROTECTION AT WORK

Getting the right hearing protection is important, too little protection and employees remain at risk of hearing damage, while too much protection and people start to feel isolated, unable to hear things like forklifts or other vehicles, or simply unable to hear colleagues speak, so they don’t wear the protector properly to let more noise through, and are at risk of hearing damage again.

Remember, in hearing protection, strongest is not always best.

There is a list of common questions about hearing protection at the bottom of the page.

How do you know hearing protection is strong enough?

You should aim for around 70 to 78 dB under the protector - that’s the noise people actually hear.

79 to 80 dB is also OK but I would steer clear of that personally as it is getting too close to the upper noise limit where hearing starts to be damaged - someone wearing it slightly incorrectly could easily then be at risk.

65 to 69 dB is again OK. The HSE class that as a little too strong but if it is good for other risks within the company then it is fine. As a guide, this is about the noise level of an office so not horrendously quiet - your production staff would just be a the same noise level as your office staff.

64 dB and below is too strong and should be avoided. People tend to not put plugs in properly or off-set ear muffs to let more noise through as they can’t hear what’s going on. They are then at risk and the employer is wasting money on hearing protection that’s not actually doing a lot.

You need two bits of information to make a decision.

1) The protector’s SNR.

This is how many decibels the hearing protection reduces the noise level by and will be on the pack, sales listing, or box, and will just say ‘SNR 34 dB’ for example. Ignore all the other numbers, you just want the SNR.

2) The noise level.

Obviously, you need to know the noise level in the workplace. Now, slightly complicating it… What you technically need is the average dB(C), so not the dB(A), the noise level you compare to the 85 dB(A) limit, and not the peak dB(C) - that’ll be the biggest number. Your noise assessment should tell you that average dB(C) level.

If you don’t have it then all is not lost, average dB(C) and average dB(A) are usually pretty close in the important 85 to about 95 dB range, so if you don’t have the average dB(C), using the average dB(A) will be thereabouts for you.

Noise nerd waffle: Average dB(C) does diverge from dB(A) at lower volumes, as dB(A) goes down the dB(C) can start to be quite different - e.g. levels of 74 dB(A) and an average of 85 dB(C) are not uncommon. Conversely, when it gets really loud dB(C) often starts to be slightly below the dB(A). But in the main region we are normally talking about they are usually close so using the dB(A) is better than nothing and has you in the right region.

Although, getting me in to do a proper noise assessment giving you those average dB(C) levels would also be a good solution. Now that is slick sales patter.

Calculating if hearing protection is suitable for your noise risk

You have a couple of routes here.

Route 1: Use my free hearing protector assessment tool

I am a thoroughly lovely noise nerd and in the resources section of this site you will find a free hearing protection suitability assessment tool. Just go there, put the SNR into one box, put your noise level in the other box, and Robert’s your mum’s brother, it will tell you if the protector is good for your site.

Link: Hearing protection assessment tool

Route 2: Do the calculation yourself

This is actually dead easy, frankly writing the code for that free hearing protection assessment tool was far harder than manually working it out, but I did like the challenge.

So, to do it manually:

Take your noise level. For an example, let’s say 95 dB(C) as the average noise level.
Subtract the SNR of the protector from it. So for the example, let’s say the SNR is 30 dB, so that’s 65 dB.
Add 4 dB back on to allow for slightly incorrect usage. So in our example, that’s 65+4, a result of 69 dB as the noise the person gets under the protector.

69 dB is damn close to the ideal range of 70 to 78 dB, so that’s good, we like that one.

Other methods of calculation

There are two other ways of doing the same thing, HML and Octave Band. Noise assessors love Octave Band but I’ll let you into a secret, it makes absolutely sod-all difference over using the simple SNR, it just looks complicated. 99% of the time the Octave Band route gives exactly the same answer as the SNR one.

HML is in the middle, a bit more complicated than SNR, less complicated than Octave Band.

As you are presumably not a noise nerd with far better things to do with your day, use SNR. The HSE list it in L108 as one of the three acceptable ways to assess hearing protection suitability so if it is acceptable in there, go for it.

SNR vs NRR

One side-note, I see a lot of no-brand hearing protection on places like Amazon.co.uk listing NRR as the rating of how powerful they are. Do not use this. NRR is the standard used by our American brethren but it is not the same as SNR, the numbers can be quite different. NRR is for people who think it is normal to have spray cheese in a can, or that having active shooter drills in schools is an unavoidable but necessary fact of life. They look like us but they are not always the same as us and NRR is just for them. If you see a listing on somewhere like Amazon.co.uk where the retailer is only giving the NRR figure, move on and don’t buy it.

E-A-R Soft FX ear plugs, among the strongest hearing protection on the market with an SNR of 39 dB. Brilliant for trying to sleep in noisy hotels but pretty much no workplace needs this level of protection.

Strongest is not always best.

There is nothing wrong with foam ear plugs as hearing protection and they come in a huge range of strengths. The lowest attenuating hearing protection on the market are foam plugs with an SNR of 14 dB, while the strongest on the market are also foam plugs with an SNR of 39 dB, and they cover all points between.