Hearing Protection Selection - A guide

The selection of hearing protection for noise at work is a simple process as long as you have the right equipment and are competent in its use. There are three methods for predicting the overall attenuation or the effectiveness of hearing protection at your disposal. Each method is slightly different and range from the simplest to the highly accurate form of calculation.

As a minimum, you will need an integrating Class 2 Sound Level Meter, for example a Pulsar Nova Model 44, that can ‘measure’ LAeq and LCeq (not to be confused with Peak dBC). Importantly, you should only consider hearing protection that conforms to EN 352-1 and which comes with a Technical Specification that includes its ‘Performance Numbers’.

1. Hearing Protection Selection with the SNR Method (Single Number Rating)

If you use the SNR Method, you need the measured LCeq plus the SNR taken from the Hearing Protector Technical Specification. Insert manually these two figures into the HSE noise exposure calculators spreadsheets available from the UK's HSE website.

2. Hearing Protection Selection with the HML Method (High, Medium, Low).

When using the HML method, you need both the measured LAeq and LCeq (not to be confused with Peak dBC) plus the H, M and L numbers taken from the Hearing Protector Technical Specification. These represent the value for the attenuation at high, medium and low frequencies.

3. Hearing Protection Selection with the Octave Band Analysis Method

For really noisy equipment with measured LAeqs consistently in the mid 90 decibels then Octave Band Analysis is the best method to use for the selection of hearing protection. This method is meant to be the most accurate way of measuring the effectiveness of hearing protection as it is looking at the actual frequencies of noise experienced by a worker. For this, you will need a sound level meter that is capable of measuring noise at octave bands centre frequency (in Hertz or Hz) such as the Pulsar Nova 46. In this case, the software that is supplied with this type of equipment will do all the work for you.

Pulsar Instruments offers a range of noise measurement equipment to help you with the prescription of hearing protection using the three main methods as discussed above. For further information, please consult our website or ring our team on 01723 518011 for advice.