The following table gives a quick guide to select the most suitable hearing protection based on a simple A-weighted noise measurement.
This table is provided by the UK Health and Safety Executive, who state that this is not a substitute for using one of the other three methods (SNR calculation, HML or Octave Band). This method will not be suitable if the noise is tonal or has a significant low frequency content.
Sound Level dB
|85 to 90||20 or lower|
|90 to 95||20 to 30|
|95 to 100||25 to 35|
|100 to 105||30 or higher|
SNR stands for Single Number Rating. It is provided by the manufacturer of the hearing protector, often printed on the side of the box.
The SNR is usually used along with the C-Weighted Sound Level to calculate the level at the ear. The SNR is used by most European countries and is similar in principle to the NNR method used in the USA and some other regions, but the calculations are a little different.
The Simple SNR Table method is only intended as a guide and will not be suitable for all noise types. We recommend using one of the following three methods: