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SELECTION

WHAT IS SNR? OVERPROTECTION 80dB - Desired average exposure level for the wearer

Hearing protection is given a Single It should be understood that Measure working Example: 116dB
Number Rating (SNR). The SNR is a general the highest SNR value is not environment sound level
means of comparing the protection levels always the most suitable. It
of different ear defenders. is possible to over protect by Subtract average exposure level 116dB - 80dB
preventing the wearer from from working sound level
EXPOSURE LEVEL hearing important sounds
such as warning signals or Resultant Required Noise = RNR of 36
The aim when selecting suitable hearing approaching vehicles. Reduction (RNR)
protection is to achieve an average = Sonis®3
exposure level of 80dB for the wearer. MAKE SELECTION Select ear defender with a SNR SNR 36dB
closest to the RNR calculation
EXPOSURE TIME To calculate the required
noise reduction and select the
The amount of time spent in a loud appropriate protection it is
environment can determine which level necessary to follow the simple
of protection is required but generally it steps to the right:
is based on an 8hr working day.

HOURSHOOUFRSUOSFEUSPEEPRERDDAAYY FFOOR RTHETHdBE(Ad) LBE(VAEL)OLFEAVTEALSKOF A TASK

¼½ 1 2 34 5 6 7 8

dB(Ad)B(LA)ELVEEVELL OOFFEXEAXMAPLMEPTLASEKSTASKS 140 PNPEUUHMNAACMTHICMPRREIEVRSEDSTEERRSILL CHAINSAWS OXYGEN TORCH 115
135 NAIL GUN WOOD CHIPPER GENERAL FOUNDRY WORK 110
130
125 LEAF BLOWER
120
115

110 FARM WORK GENERAL FACTORY WORK
MOTORCYCLE ENGINE

105

100 GRINDING AND CUTTING WHEELS CONCRETE POURING 105
95 BUSPYRHTINRAATNFPFDRICEDSRSILL BLAST CHILLERS 100
90 BELT SANDER
85 LAWN MOWER
80
75

This chart uses decibel levels of workplace environments and has example tasks to give an idea of real world sound levels. It
includes the amount of time that you could potentially spend in a particular environment. This chart is for general guidance
only and should not be considered a substitute for a full risk assessment.

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