The CAOHC certification exam assesses your knowledge of occupational hearing conservation principles and OSHA's Hearing Conservation Standard (29 CFR 1910.95). Whether you're preparing to become an Occupational Hearing Conservationist (OHC) or a Certified Occupational Hearing Conservation Supervisor (COHC), having a printable PDF study resource lets you review key concepts anywhere — no internet required.
Our free CAOHC practice test PDF covers the core domains tested on the certification exam: noise measurement, audiometric testing procedures, standard threshold shift interpretation, hearing protection device selection, and employee training requirements. Download it below and pair it with our full CAOHC practice test online for the most complete preparation.
The CAOHC certification exam is based on the curriculum delivered in approved training courses. You'll need a solid understanding of every major domain before sitting the exam.
You must understand how to use dosimeters and sound level meters to measure occupational noise. Key concepts include the decibel (dB) scale, A-weighting (dBA), time-weighted average (TWA) calculation, and the 5 dB OSHA exchange rate (doubling the dose for every 5 dB increase). Noise dose percentages and action vs. permissible exposure levels must be committed to memory.
OSHA 29 CFR 1910.95 requires employers to establish an audiometric testing program for workers exposed at or above the 85 dBA action level. Exam content covers baseline and annual audiogram requirements, audiometer types (pure-tone air conduction), calibration schedules (acoustic calibration daily, exhaustive annually), qualified technician requirements, and quiet testing environment standards.
Candidates must interpret audiograms and identify Standard Threshold Shift — defined as a 10 dB or more average shift at 2000, 3000, and 4000 Hz compared to baseline. Noise-induced hearing loss (NIHL) produces a characteristic notch at 4000 Hz. Normal hearing thresholds are 0–25 dB HL; classifications progress through mild, moderate, severe, and profound ranges.
The exam tests knowledge of HPD types (foam earplugs, pre-molded plugs, earmuffs, semi-inserts), the Noise Reduction Rating (NRR), and how to calculate effective protection. OSHA requires dividing the NRR by 2 and subtracting from the measured noise level when using dBA measurements. Proper fit, training, and motivation for consistent HPD use are also tested.
Under 29 CFR 1910.95, employers must train employees annually on the effects of noise, purpose and use of HPDs, and audiometric testing procedures. Recordkeeping obligations include retaining audiometric test records for the duration of employment plus 30 years.
The PDF above is perfect for offline review, but online practice is just as important for building exam confidence. Our CAOHC practice test covers all exam domains with immediate answer feedback, detailed explanations, and timed quiz modes. Use both resources together to maximize your score on exam day.