Identifying appropriate hearing protection
Here's a question, what is better, ear defenders or ear plugs? (I used to always say 'ear muffs' myself but over the years that so regularly descended into Carry On style smut and quiet sniggering by attendees on noise awareness courses that I taught myself to use 'defenders' instead, but they are one and the same).
Some protectors are much more powerful than others but that does not mean they are 'better' as there is such a thing as too powerful. Like health and safety in general, too much safety can be a bad thing and what you want is just the right amount of protection for the noise risks you have. If you want more on the different styles there is a page here on plugs versus defenders.
The reasons it gets complicated
Hearing protectors are not a case of either looking for ones with the biggest claims on the packaging for the number of dB it claims to reduce noise by (the SNR) and choosing the one with the biggest number, or choosing the cheapest. Conversely, trying to do the right thing and just choosing the most expensive is no good either for that matter.
When you have a noise exposure at work, the noise will naturally be focused towards certain frequencies, so your level of say 90dB(A) could be 90dB(A) focused towards the higher pitched noises or could be 90dB(A) more tilted towards the lower end of the scale. At the same time, almost all hearing protectors have a frequency at which they perform the best so when they say they have a noise reduction of 28dB, that could be 28dB focused towards the higher frequencies or could be at the lower ones. It is important therefore that the two match - there is no point having a hearing protector which is brilliant at high frequencies but rubbish at lower ones if your noise is mostly lower end stuff. In this case your hearing protector may say it does 28dB of noise reduction goodness but in reality your people will be getting a lot less, and may still be exceeding the 85dB(A) limit and exposed to the risks of hearing loss.
Price of hearing protection
The one thing I would always caution against is buying hearing protection purely on price. This isn't because cheap is always rubbish as in many cases cheap ear plugs or ear muffs may be perfectly good for the noise risks you have, while conversely a really expensive pair of hear defenders may be built to last until the 23rd Century but not be powerful enough for the noise you are trying to control. Price is not that great an indicator of how powerful or suitable a hearing protector is.
Higher price by the way is not synonymous with more powerful protection, it really has very little bearing on how strongly the protector reduces noise levels. For example, the E-A-R Push-In plug will knock about 38dB off the noise and are around 58p per pair, while the Flare Audio ISOLATE Pro plugs are actually a little weaker so offer slightly less protection and knock about 36dB off while costing £50 a pair. Both are reusable. Paying £50 gets you a lower level of protection than paying 58p. Flare ISOLATE plugs just have better marketing to justify their price.
SNR, HML and Octave Band
So, if price isn't good enough, you then need to have some means of deciding if hearing protection is good enough. Think of these three methods as 'OK', 'bit better and not too shabby', and 'the mutt's nuts'.
SNR is a bit like holding a wet finger up in the air to decide if it is windy, HML is better, while octave band measurements are the other end of the scale with a fancy all-singing spinning anemometer thing giving you exact wind speeds.
To be clear, all are compliant with the Noise Regs., just that some are better than others.
I'll cover each of these in their own page linked over there on the upper left as they can take a little bit of explaining, so have a gander at the menu and click away to your heart's content. (Although let's face it, your heart is probably telling you that you have a desperate urge to go and read Facebook rather than some geek droning on about noise...).
Styles to make available
When you make hearing protection available my advice is always to have at least one style of ear defenders and one style of ear plugs available to employees and let them choose which they want. Some users hate the tightness and heat of ear defenders or muffs while others hate putting things inside their ears or even sometimes find plugs mildly painful. At the end of the day you need compliance with their use so make both available.
You may also need to make different styles available to different people. For example you may choose a protector which reduces the noise levels experienced by someone on the factory floor to around 70dB, but maybe you don't want to reduce it quite so much for your fork lift truck drivers so they can hear people around them, so provide them with a protector which only reduces the noise experienced to around 78dB or so.