CAOHC TEST QUESTIONS AND ANSWERS 2025/2026

CAOHC TEST QUESTIONS
AND ANSWERS
1.


Question: What is the OSHA action level for occupational noise exposure?
Answer: 85 dBA time-weighted average (TWA) for an 8-hour shift.


2.


Question: What is the permissible exposure limit (PEL) for occupational noise
exposure under OSHA?
Answer: 90 dBA TWA for 8 hours.


3.


Question: At what noise level must an employer implement a Hearing Conservation
Program (HCP)?
Answer: At or above 85 dBA TWA.


4.


Question: What is the primary purpose of the baseline audiogram?
Answer: To establish a reference hearing threshold for future comparison.


5.

,Question: When must the baseline audiogram be obtained?
Answer: Within 6 months of an employee’s first exposure at or above the action
level (or within 1 year if using a mobile van, provided employees use hearing
protection until then).


6.


Question: What frequencies are tested in a standard audiometric test for
occupational hearing conservation?
Answer: 500 Hz, 1000 Hz, 2000 Hz, 3000 Hz, 4000 Hz, 6000 Hz, and 8000 Hz.


7.


Question: What is a Standard Threshold Shift (STS) according to OSHA?
Answer: An average shift of 10 dB or more at 2000, 3000, and 4000 Hz in either ear,
compared to baseline.


8.


Question: How soon must employees be notified of a Standard Threshold Shift?
Answer: Within 21 days of determination.


9.


Question: What are the two main types of hearing protection devices (HPDs)?
Answer: Earplugs and earmuffs.


10.


Question: What is the purpose of the Noise Reduction Rating (NRR)?

, Answer: To estimate the amount of sound attenuation a hearing protector can
provide.


11.


Question: How is the OSHA “derated” NRR calculated?
Answer: Subtract 7 dB from the NRR and then divide by 2.


12.


Question: What is the most common cause of sensorineural hearing loss in the
workplace?
Answer: Long-term exposure to hazardous noise.


13.


Question: Which type of hearing loss is usually permanent: conductive or
sensorineural?
Answer: Sensorineural hearing loss.


14.


Question: Who is permitted to perform audiometric testing under OSHA?
Answer: Audiologist, otolaryngologist, physician, or a technician certified by CAOHC
under the supervision of a physician or audiologist.


15.


Question: What is the purpose of daily biological checks (listening checks) of the
audiometer?
Answer: To ensure the audiometer is functioning properly before testing employees.