Products
Ear Protection Through Noise Attenuation
Attenuation is the reduction in noise that ear defenders give. Attenuation should neither be too high or too low and ear defenders should be chosen for comfort, areas of usage and the type of noise that is to be protected against. The important thing is to be under 85dB but not to a level that cuts off all sound as this can be dangerous and often results in the ear defender been lifted which exposes the ear to the noise that is being protected against. This Product Guide contains a range of ear defenders that give differing levels of protection so that there is a choice to suit differing work environments. The details on each model include a table which shows the noise reduction applicable to that model and an SNR (single number rating) or average attenuation. The table below shows typical noise levels in different environments, by deducting the SNR rating from the dB level shown in the table you can select the ear defender that gives a predicted noise level of 85dB or below. You should note, however, that this is a simplified calculation method which does not take account of the characteristics of the noise and at levels above 95dB an accurate noise assessment should be made.
Some examples of noise over 85dB A weighted sound level
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120-150 Airports, jet motors, race tracks 115-130 Mines 110-120 Pneumatic drills 105-120 Forestry machinery 105-115 Cargo machinery 100-115 Concrete industry 100-115 Textile industry 100-115 Smithery |
100-110 Road work 100-110 Ship’s machine room 100-110 Rivet hammer 95-105 Heavy tractor 90-105 Sheet metal shop, general workshop noise 85-100 Hand held electric power tool 85-95 Lighter tractor 80-85 Light industry, working with children etc. |
The predicted noise level is calculated by taking the measured noise level (or as a guide from the table shown above) minus the SNR shown in the individual item tables. The resulting number is the predicted noise level which should be below 85dB for the ear defender to give adequate protection. Please note that this is a simplified calculation that gives an indication only, for a more accurate result noise levels should be measured correctly and a calculation made using a method that takes account of different octave levels.
Detecting Harmful Noise
Harmful noise is a combination of sound level and the length of time one is exposed to the noise. For example, exposure to 100dB A weighted sound for 15 minutes is the equivalent to 8 hours exposure to 85 dB A weighted sound. It is, therefore, important to have an understanding of how much noise exists in the work place.
At 80dB prolonged exposure can cause slight hearing loss and ear protectors are recommended. At 90dB prolonged exposure can cause moderate to severe hearing loss and ear protection should be carefully selected to suit the noise type and level. At 100dB and above even short exposure can cause permanent hearing loss and the correct choice of ear defenders is even more important.
EU Noise Directive
The Noise Directive 2003/10/EEC is one of a series of directives designed to ensure that employees are protected from physical as opposed to chemical hazards. Hearing loss is one of the most common industrial injuries and, despite some success in reducing it due to earlier legislation, continues to cost industry dearly whilst making retirement a misery for many.
