4.1 What is Hearing Protection Fit Testing?
Fit Testing Evidence
What it is: Fit testing is the process of verifying the amount of noise reduction, or attenuation, an individual worker achieves with a specific hearing protector.
It provides a measure of how well the hearing protector is working for that person, in that moment.
The primary output is a Personal Attenuation Rating (PAR), which can be compared directly to the specified Single Number Rating (SNR).
Why it is critical: Research, including the HSE's own RR720 report, has shown that the real-world protection achieved by workers is often significantly lower than the manufacturer's stated attenuation (e.g., SNR). This is due to factors like poor fit, incorrect insertion, and anatomical differences between individuals. Fit testing is the only way to bridge this gap and verify that the protection is adequate for the individual, as required by the Control of Noise at Work Regulations (Regulation 7(4)(a)).