Personal Protection Evaluation

Quantify the real-world attenuation of hearing protector devices and verify the protection of the wearer (no over-protection, no under-protection and in line with legal requirements).

This protocol is applied to the result of Microphone In Real Ear (MIRE) , an objective acoustic fit-testing method for 2 channel-designed custom earplug. The test is implemented while the earplug is being worn by the user under high noise load (> 85dB(A)).

The graph visualizes the residual noise level . being the result of the microphone measuring the sound pressure under the earplug. This should not exceed the red line that represents the health-based safe limit Furthermore, the difference in sound pressure between the 2 microphones provides the real- world attenuation , presented as single number rating (SNR MIRE) and per group of related frequencies (High-Mid-Low). Finally, based on the user’s personal daily noise exposure level (Lep,d) the protection function is checked considering the locally applicable legal requirements, the health-based safe limit and preservation of communication.

Emphasis on laboratory attenuation values and reliance on these numbers for predicting the protection of the wearer is both unwarranted and potentially harmful to the effectiveness of a hearing conservation program. The ‘Personal Protection Evaluation’ tool is game changing for professionals when it comes to quantifying the real-world attenuation of custom earplugs and assessing their protective function during exposure.

Rapport-HPD-Compliance (1)