Hearing Protection Fit Testing
Stop Guessing. Start Measuring.
The number on the box isn't what your workers are actually getting. Measure real protection for every employee - in 90 seconds.
90 sec
per test
NRR ≠ PAR
see the real gap
Independent 1910.95 Audit
Third-Party Reviewed
FDA Registered
Class II Medical Device
SOC 2 Type II
AICPA Certified
HIPAA Compliant
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Made in USA
Engineered & Built
One Device. Two Tests.
Zero Extra Equipment.
The same Soundtrace audiometer that runs your audiometric tests also performs HPD fit testing. No additional hardware, no separate appointments, no extra cost.
Soundtrace Audiometer
Audiometric testing + HPD fit testing in one calibrated device
Audiometric Test
Pure-tone audiogram at standard frequencies
HPD Fit Test
Occluded thresholds measure real PAR
No Extra Hardware
If you have a Soundtrace audiometer, you already have a fit testing system. No additional devices, calibrations, or purchases needed.
Same Visit, +90 Seconds
After the audiogram, the employee keeps the headphones on, inserts their earplugs, and occluded thresholds are measured. No separate scheduling.
Audiogram = Baseline
The unoccluded audiogram serves as the reference. PAR is calculated from the employee's own hearing — not population averages.
One Complete Record
Audiogram and fit test results are stored together — one hearing conservation record per employee, linked for 30+ years.
The Protection Gap
NRR Label vs. Real-World Protection
Click each HPD type to see how lab ratings compare to what workers actually receive.
NRR (Label Rating)
33
dB (lab conditions)
Average Gap
Avg. Measured Protection
14
dB (measured fit)
Individual Variation Range
Why Fit Testing Matters
Because "We Gave Them Earplugs" Isn't Enough
The gap between rated protection and real-world protection is the #1 blind spot in hearing conservation programs. Unverified protection drives hearing loss, workers' comp claims, and long-term civil liability.
Find Out What Protection Workers Actually Get
The rating on the box is a lab number. In the real world, most workers get maybe half that protection. Our fit testing measures the actual noise reduction each employee gets with their specific earplugs, inserted the way they actually do it - not the way a lab technician does it.
90-Second Fit Check Process
The fit test integrates directly into the existing audiometric testing workflow. After the audiogram, the employee keeps the headphones on, inserts their earplugs, and the system measures occluded thresholds at 500, 2000, and 4000 Hz. Total added time: about 90 seconds per employee.
See the Full Picture: Noise + Protection
When noise exposure data is available, the system automatically calculates whether each worker is actually protected. You'll know instantly if someone's protection puts them in the safe zone, is blocking too much (risking communication issues), or not blocking enough (risking hearing damage).
Each Ear Tells a Different Story
We test each ear independently because left and right ears often get very different protection levels. Hand dominance, insertion technique, and ear shape all play a role. Testing both ears separately lets you identify which side needs attention and focus retraining where it matters.
How It Works
From Audiogram to Verified Protection
Fit testing picks up right where the audiometric test leaves off - same visit, same equipment, 90 more seconds.
Insert Earplugs
~30 sec
Employee inserts their own hearing protection exactly the way they normally would on the job - no coaching, no adjustments. This captures their real-world fit, not a lab-ideal insertion.
The test uses the employee's actual earplugs (foam, pre-molded, or custom) to measure real protection.Run Fit Test
~60 sec
The system measures occluded hearing thresholds at 500, 2000, and 4000 Hz for each ear independently, then compares against the unoccluded audiogram baseline to calculate actual attenuation.
Uses the REAT (Real-Ear Attenuation at Threshold) methodology - the gold standard defined by ANSI S12.6.See Your Results
Instant
PAR score, fit category, and - when noise exposure data is available - protected exposure level are calculated instantly. Bad fits trigger immediate refit with coaching and alternate protectors.
Results are documented and stored with the audiogram for a complete hearing conservation record.What You See Instantly
Personal Attenuation Rating
22 dB
vs. NRR 33 dB on the box
67% of rated protection
Fit Category
Strong, consistent noise reduction
Protected Exposure
70 dBA
TWA 92 dBA − PAR 22 dB
Results are stored with the audiogram - one complete hearing conservation record per employee.
HPD Adequacy Calculation GuideInteractive Demo
See How Fit Assessment Works
Explore how the rating on the box compares to real-world protection, and how combining noise data with fit data reveals whether your workers are actually protected.
Fit Assessment Categories
Noise + Protection Calculator
Box Rating (NRR)
29 dB
Actual Protection (Measured)
22 dB
Protected Exposure
66 dBA
Target Range
Protected Exposure = Noise (88 dBA) − Protection (22 dB) = 66 dBA. This worker's protection is in the safe target range.
The Protection Gap
Why NRR Isn't Enough
The number on the earplug box tells you what's possible. Fit testing tells you what's real.
Tested under perfect lab conditions with trained technicians
OSHA requires employers to cut NRR in half for noise dose calculations
What most workers actually get due to poor insertion, fit, and seal
What the Regulations Say
OSHA 29 CFR 1910.95
Requires employers to "ensure" hearing protection is effective and that employees are properly trained in its use. Employers must derate the NRR by 50% when calculating noise dose.
NIOSH Guidance
Recommends individual fit testing as the most reliable method to verify real-world HPD effectiveness. Recognizes that labeled NRR overestimates actual protection for most workers.
ANSI S12.6-2008
Defines REAT (Real-Ear Attenuation at Threshold) methodology - the gold standard for measuring actual hearing protection attenuation used by Soundtrace.
"The only way to know what protection your workers are actually getting is individual fit testing."
Exposure-Based Decisions
TWA + PAR = Protected Exposure
When fit testing is connected to noise exposure data, you don't just know if the earplug fits - you know if the worker is actually protected.
Select a Workplace Scenario
TWA Exposure
92 dBA
HPD Type
Foam Earplugs (NRR 29)
Target Range
65–85 dBA
OSHA PEL
90 dBA
Protected Exposure by Fit Quality
70 dBA
✓ In target range
78 dBA
✓ In target range
87 dBA
⚠️ Underprotected - refit needed
Common Concerns
What EHS Teams Ask Us Most
Is fit testing required by OSHA?
Not explicitly mandated - yet. But OSHA and NIOSH both recognize fit testing as a best practice, and the regulatory trend is moving toward it. More importantly, if an employee develops hearing loss and you can't demonstrate their protection was actually effective, you're in a much weaker legal position than if you have documented results showing verified protection.
We already provide earplugs - isn't that enough?
Providing earplugs checks one box, but it doesn't prove they're working. The NRR on the package assumes perfect insertion - which almost never happens in the field. OSHA requires you to derate the NRR by 50% for a reason. Fit testing proves whether each employee's specific earplugs, inserted the way they actually do it, provide adequate protection. It's the difference between 'we gave them PPE' and 'we verified their PPE works.'
How long does it take? We can't afford more downtime.
The fit check adds roughly 90 seconds to the existing audiometric testing workflow. Total integrated process - training, audiogram, and fit test - is about 15.5 minutes per employee. Since you're already pulling them for an audiogram, the incremental time is minimal. And it's far less disruptive than a workers' comp claim from inadequate protection.
Common Questions
Fit Testing FAQ
Everything you need to know about HPD fit testing, PAR vs NRR, and how it integrates with your hearing conservation program.
Showing 9 results
Why can't I just rely on the NRR rating?
What does OSHA actually say about fit testing?
How does PAR differ from NRR?
What frequencies are tested during the fit check?
What happens when we identify a bad fit?
How do results connect to audiometric testing?
Can we test different types of hearing protection?
What about overprotection risks?
Why does TWA integration improve fit testing decisions?
Related Resources
Continue exploring the Soundtrace platform
Audiometric Testing
Run OSHA-compliant hearing tests that automatically trigger fit testing workflows.
Learn moreNoise Monitoring
Match protection ratings to actual noise exposure by zone and shift.
Learn moreRecordkeeping
Digital fit test records with PAR scores, HPD models, and refit history.
Learn moreCase Studies
See how organizations verified real-world protection with Soundtrace.
Learn moreIndustry Solutions
HPD fit verification for extreme noise environments in metals and manufacturing.
Learn moreBlog
NRR de-rating, PAR scoring, and earplug fit testing best practices.
Learn moreReady to Verify Your Protection?
See how REAT-based fit testing can close the gap between rated and real-world hearing protection.