4.3 Types of Fit Testing

Primary guidance: UKHCA Hearing Protection Fit Testing — An Introductory Guide (BOHS):

Types of Hearing Protection Fit Testing

Hearing protection fit testing checks whether a specific hearing protector (usually earplugs) is delivering the expected level of attenuation for the individual wearer. Different ear canals, fitting technique, comfort, and training all affect real-world protection — so two people wearing the same plug can get very different results.

In the UK, the most commonly referenced fit testing approaches include F-MIRE and audiometric fit testing, because they provide a quantitative Personal Attenuation Rating (PAR).

Subjective Fit Testing (Measured PAR)

Subjective fit testing provides a numerical result (PAR) showing how much protection the wearer is actually achieving with that specific hearing protector.

What it’s useful for

• Verifying protection for higher-risk roles and noisy environments

• Demonstrating “fit achieved” after training or coaching

• Comparing different earplug types/sizes to find the best real-world result

• Building clear records and evidence for hearing protection programmes

What it doesn’t do

• It doesn’t guarantee the wearer will fit the plug correctly every day without training/supervision

  
  

Objective Fit Testing (Measured PAR)

F-MIRE typically uses a probe microphone setup to measure sound levels and estimate the attenuation achieved with the hearing protection in place. It outputs a result (PAR).

Typical outcomes

• You identify poor insertion quickly

• Coaching + re-test shows improvement

• You can select a better plug type/size based on measured results

Audiometric fit testing

Audiometric fit testing uses a hearing-test style method to determine attenuation using tones, producing a PAR. It can be useful where the testing approach aligns with audiometric style measurement and you want a clear numerical result.

Web Based Fit Testing

Web based fit testing does not rely on audiometric thresholds and is therefore more accessible

Acoustic Leak Testing

Acoustic Leak Testing establishes that the mould protection fits correctly but does not produce a PAR

Which method should you choose?

Most employers choose a method based on:

• risk level and noise exposure

• workforce size and logistics

• need for records (PAR)

• training requirements and consistency

• ease of repeat testing

If you’re unsure, start with the goal: Do you need a measured PAR, or is Acoustic Leak Test sufficient for your program.

Related entries

• What is Hearing Protection Fit Testing? (overview + why it matters)

• Audiometric Fit Testing (deep dive)

• PAR — Personal Attenuation Rating (what the number means)

  
  

Reference

UKHCA Hearing Protection Fit Testing — An Introductory Guide (BOHS PDF):https://www.bohs.org/app/uploads/2022/02/UKHCA-Hearing-Protection-Fit-Testing-%E2%80%94-An-Introductory-Guide.pdf