Understanding audiogram patterns is essential for EHS managers who review occupational audiometric surveillance results. This guide covers high-frequency sensorineural hearing loss: what it looks like on an audiogram, what it means clinically, what OSHA 1910.95 obligations it triggers, and the required employer response. Note that audiogram interpretation in the context of OSHA compliance always requires involvement of a licensed Professional Supervisor — a licensed audiologist, otolaryngologist, or other physician. The EHS manager's role is to understand the pattern well enough to act appropriately and ensure timely PS review.
Soundtrace provides audiometric testing supervised by a licensed audiologist who reviews all audiograms, identifies STSs, and makes clinical determinations — ensuring employer compliance with every 1910.95 audiometric obligation.
What Is High-Frequency Sensorineural Hearing Loss?
High-frequency hearing loss appears on an audiogram as elevated hearing thresholds (worse hearing) at the higher test frequencies — typically 3000, 4000, and 6000 Hz — with better (lower) thresholds at 500 and 1000 Hz. The characteristic noise-induced pattern shows a notch at 4000 Hz with partial recovery at 6000 or 8000 Hz, reflecting where the cochlea is most vulnerable to mechanical damage from excessive noise.
Clinical Significance
High-frequency hearing loss in the 3–6 kHz range impairs the perception of consonants like 's', 'f', 'th', and 'sh' that carry most of the intelligibility information in speech. Workers with this pattern often report difficulty understanding speech in noise while being able to hear that someone is speaking. They may miss safety warnings, verbal instructions, or alarms that contain high-frequency components.
All clinical interpretations of occupational audiograms — including determinations of audiogram pattern, work-relatedness, and STS confirmation — must be made by the Professional Supervisor (licensed audiologist, otolaryngologist, or other physician) under OSHA 1910.95(g)(3). EHS managers should understand these patterns to recognize when PS review is needed and to act on PS findings promptly, not to replace the PS role.
OSHA 1910.95 Implications
For OSHA purposes, high-frequency hearing loss is analyzed as a Standard Threshold Shift if the average shift at 2000, 3000, and 4000 Hz in either ear equals or exceeds 10 dB compared to baseline. A worker who develops a 4 kHz notch with adequate thresholds at 2000 Hz may not have met the STS definition yet — but the early notch is a sentinel finding that indicates cochlear damage is occurring and HPD adequacy should be reassessed. See: standard threshold shift: OSHA definition and action guide.
Required Employer Response
A developing 4 kHz notch in a noise-enrolled worker means their current hearing protection is not providing adequate protection, the noise monitoring data is out of date, or both. HPD fit testing verifies actual attenuation. See: HPD fit testing guide.
If the threshold shift at 2000, 3000, and 4000 Hz averages 10 dB or more compared to baseline, an STS is confirmed with its associated notification and response obligations.
A Professional Supervisor may revise the baseline to a better audiogram if the current audiogram shows improvement. For worsening audiograms, the original baseline is retained to ensure STSs are captured accurately.
Audiologist-supervised audiometric testing with automatic STS detection
Soundtrace audiometric testing is supervised by a licensed audiologist who reviews every audiogram, identifies all STSs, and makes clinical determinations — ensuring your program meets every 1910.95 requirement.
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High-frequency hearing loss appears on an audiogram as elevated hearing thresholds (worse hearing) at the higher test frequencies — typically 3000, 4000, and 6000 Hz — with better (lower) thresholds at 500 and 1000 Hz. The characteristic noise-induced pattern shows a notch at 4000 Hz with partial recovery at 6000 or 8000 Hz, reflecting
For OSHA purposes, high-frequency hearing loss is analyzed as a Standard Threshold Shift if the average shift at 2000, 3000, and 4000 Hz in either ear equals or exceeds 10 dB compared to baseline. A worker who develops a 4 kHz notch with adequate thresholds at 2000 Hz may not have met the STS defini. The Professional Supervisor must review all audiograms with significant findings to determine STS status and work-relatedness.
The Professional Supervisor — a licensed audiologist, otolaryngologist, or other physician — must review any audiogram with clinically significant findings. OSHA 1910.95(g)(3) requires PS involvement in all STS determinations and medical referral decisions. EHS managers should not attempt to interpret audiogram patterns independently.