Over-protection - what are the issues?
Over-protection means hearing protection is too strong for the noise risk, and yes, that is an actual thing…
Over-protection often comes from well-meaning employers buying the strongest hearing protection they can find - hearing protection with the highest SNR. They mean well but it often actually increases risk and for the employer, means more of the money they spend on hearing protection is wasted.
When hearing protection is too strong people often feel isolated and too cut-off from their surroundings at work. They can’t hear vehicles around them and struggle to ear other people speaking, while people like Engineers often use how machines sound as part of the diagnostic process which is then impeded by hearing protection which is too strong.
Almost inevitably, hearing protection which is too strong means people often simply don’t wear it, or if they do they only put it in loosely - ear plugs are sticking out of their ears or ear muffs are slightly off-set and not quite fully on the ears. Often in food factories you see ear plugs held in place by the hairnet rather than inserted properly.
The people themselves are then at risk of noise damage whereas with less powerful protection it can be worn properly and the risk controlled and often they get better protection. Also, just giving people ear plugs and telling them to wear it is not enough for the employer to have met all their responsibilities so if the hearing protection is too strong and people then don’t wear it properly the employer can still be liable for any resulting damage.
A lot of the less well-established hearing protection manufacturers market their hearing protection is being strong, or ‘the strongest on the market’. These are usually the off-brand Del Boys selling on Amazon and frankly they don’t really know what they are selling and just go on strongest is best. Not only them though, Screwfix sell their own brand hearing protection and don’t seem to have a clue about what they are selling either if their Customer Services are anything to go by - I have chased them several times trying to get accurate performance data for their own-brand hearing protection but with no luck.
In a noise assessment I measure how loud the noise is and then calculate how effective the hearing protection is for that specific risk, so the employer can be sure the hearing protection is in the Goldilocks zone - not too strong, not too weak, but just right.
Calculating how effecting hearing protection is
As a rough guide, to get the right hearing protection for a noise risks, take the average decibels of the noise, subtract the SNR of the hearing protector, and add 4dB back to that result. That will tell you what people are likely to be experiencing under the protector and ideally look for an answer somewhere around 70dB or so - that’s a normal office kind of noise level.
Stronger is not better. Indeed stronger is often worse, causes increased noise exposures and employers paying for hearing protection which is not actually doing much.
