4.3.2 Audiometric Fit Testing
Fit Testing Evidence
- Can test all types of earplugs
- Uses audiometric equipment that may already be available for health surveillance
- Slower than F-MIRE (typically 10-20 minutes per test)
- Subjective (relies on accurate user response)
- Requires a quiet environment (sound booth or noise-attenuating headphones)
Primary guidance: UKHCA Hearing Protection Fit Testing — An Introductory Guide (BOHS)
Audiometric Fit Testing
Audiometric fit testing uses a hearing-test style approach (tones and thresholds) to estimate the level of attenuation achieved when a worker wears a specific hearing protector. The output is typically a Personal Attenuation Rating (PAR) — a numerical indication of the protection achieved by that individual with that specific product, fitted in that specific way.
What it’s used for
Audiometric fit testing is useful when you need measurable evidence that hearing protection is working for the wearer, for example:
verifying protection for workers in higher noise areas
confirming correct fitting technique after training/coaching
comparing different earplug types/sizes to find the best real-world result
maintaining records for hearing protection programme management
What the result actually tells you
A fit test result shows the attenuation achieved at the time of the test, with:
that wearer
that earplug/size
that fitting technique
It does not guarantee the same result every day without proper training, supervision, and retesting. Fit testing supports a hearing protection programme — it doesn’t replace noise risk assessment or other control measures.
Good practice
A strong programme uses audiometric fit testing as part of a repeatable process:
select appropriate hearing protection
train the wearer on correct fitting
fit test and record the result
coach and re-test if needed
repeat testing when products change or where ongoing assurance is required