While there are many ways to reduce noise in the workplace, noise cannot always be eliminated and this is where hearing protection needs to be used. Ear Defenders, Ear Muffs, and Ear Plugs are PPE (Personal Protective Equipment) designed to protect the wearer from extreme noises and reduce the risk of hearing loss.
The below chart from Moldex illustrates the dB level of different activities. Noise is measured in decibels (dB). An ‘A-weighting’ or ‘dB(A)’, measures average noise levels, and ‘C-weighting’ or ‘dB(C)’ measures peak, impulse or explosive noises.
You should wear hearing protection (by law) if the noise or sound level at your workplace exceeds 85 dB.
The best way to decide on whether or not protection is needed is to arrange a specialist survey. If an employee needs to raise their voice to be heard a few feet away then the noise levels may be over 85 dB and immediate action should be taken.
What does SNR mean?
SNR stands for 'Single Number Rating' . The SNR value can be used to compare the level of noise attenuation offered by different hearing protectors. To determine acoustic pressure on your ears, you subtract the SNR value from the average noise level measured, for example:
The noise level measures an average of 105 dB. You are wearing ear protection with an SNR of 30. So, the acoustic pressure on your ears is on average 105 – 30 = 75 dB.
So obviously, the higher the SNR, the higher the level of noise attenuation provided by the hearing protection.
Protectors that reduce the level at the ear to below 70 dB should be avoided, since this over-protection may cause difficulties with communication and hearing warning signals. This can lead to safety risks, and result in users removing their hearing protection and therefore risking damage to their hearing.
Failure to wear the correct protection can result in Noise induced hearing loss. (NIHL) is irreversible damage to the ears caused by exposure to high levels of noise. NIHL is the second most common form of hearing loss, after age- related hearing loss, yet it is 100% preventable if the correct level of protection is used.
It is estimated that 18,000 people have noise induced hearing loss (NIHL) caused or made worse by work in the UK.