CAOHC Occupational Hearing Conservationist Certification Exam — Questions and Answers

Question 1: What exchange rate does OSHA use for calculating noise dose?

No exchange rate is applied
10 dB doubling rate
3 dB doubling rate
5 dB doubling rate (Correct answer)

Correct answer: 5 dB doubling rate

OSHA uses a 5 dB exchange rate, meaning that for every 5 dB increase, the allowable exposure time is halved.

Question 2: The maximum permissible ambient noise levels (MPANLs) for an audiometric test room are specified by which standard?

ANSI/ASA S3.1 (Correct answer)
NIOSH Recommended Exposure Limit (REL)
OSHA 29 CFR 1910.95
CAOHC Best Practices Guide

Correct answer: ANSI/ASA S3.1

The American National Standards Institute (ANSI)/Acoustical Society of America (ASA) S3.1 standard specifies the maximum permissible ambient noise levels allowed in a test room to ensure that background noise does not interfere with the test and invalidate the threshold measurements.

Question 3: What is the role of vibrotactile alerting devices in workplace communication for hearing-impaired workers?

They provide silent vibration-based alerts for alarms, notifications, and communication signals that the worker may not hear (Correct answer)
They are only used in medical settings
They replace all audio communication in the workplace
They interfere with hearing aid function and should not be used in the workplace

Correct answer: They provide silent vibration-based alerts for alarms, notifications, and communication signals that the worker may not hear

Vibrotactile devices such as wristband vibrators or pager-style alerts provide haptic notifications that bypass hearing entirely. These are particularly valuable for fire alarms, machine alerts, and other critical notifications in environments where visual alerts may not be visible.

Question 4: How should hearing protectors be selected when workers must also wear respiratory protection?

Always use earmuffs over the respirator straps
Use earplugs rather than earmuffs since respirator straps can break the earmuff seal (Correct answer)
Use the cheapest option regardless of compatibility
Respiratory and hearing protection are never required simultaneously

Correct answer: Use earplugs rather than earmuffs since respirator straps can break the earmuff seal

Earplugs are generally preferred when workers wear respirators because respirator straps interfere with earmuff seals.

Question 5: Which of the following represents the most effective type of noise control according to the established hierarchy of controls?

Replacing a noisy piece of equipment with a quieter model. (Correct answer)
Installing acoustic enclosures around loud machinery.
Requiring employees to wear properly fitted earplugs.
Rotating workers out of a high-noise area after 4 hours.

Correct answer: Replacing a noisy piece of equipment with a quieter model.

The hierarchy of controls ranks methods of controlling hazards from most to least effective. Elimination and Substitution are at the top. Replacing a noisy machine with a quieter one is an example of substitution, which physically removes the hazard. [9] Engineering controls (enclosures), administrative controls (job rotation), and personal protective equipment (earplugs) are progressively less effective because they rely on additional actions or worker behavior to be successful. [3, 8]

Question 6: What exchange rate does OSHA use for calculating noise dose?

2 dB exchange rate
3 dB exchange rate
10 dB exchange rate
5 dB exchange rate (doubling rate) (Correct answer)

Correct answer: 5 dB exchange rate (doubling rate)

OSHA uses a 5 dB exchange rate, meaning that for every 5 dB increase in noise level, the permissible exposure time is halved. At 95 dBA, the permitted time is 4 hours; at 100 dBA, 2 hours; and at 105 dBA, 1 hour.

Question 7: An occupational hearing conservationist is measuring noise levels in a manufacturing plant. To best assess the potential risk for noise-induced hearing loss for employees, which sound level meter weighting scale should be used?

A-Weighting (Correct answer)
Z-Weighting (Flat)
C-Weighting
B-Weighting

Correct answer: A-Weighting

A-weighting (dBA) is the standard for occupational noise measurements because it mimics the frequency response of the human ear and has been shown to correlate well with the risk of noise-induced hearing loss. C-weighting is less sensitive to low frequencies and is often used for measuring peak sound pressure levels or entertainment noise. Z-weighting has a flat response and does not account for the ear's varying sensitivity to different frequencies.

Question 8: What is the OSHA ceiling limit for impulse or impact noise?

115 dBA
150 dB peak SPL
130 dB peak SPL
140 dB peak SPL (Correct answer)

Correct answer: 140 dB peak SPL

OSHA sets a ceiling of 140 dB peak SPL for impulse or impact noise.

Question 9: Which of the following is a subjective method to check for a proper earplug fit after insertion?

Visually inspecting that the end of the earplug is flush with the ear canal opening.
Asking the employee if their own voice sounds deeper or louder. (Correct answer)
Performing a quantitative fit test to calculate the Personal Attenuation Rating (PAR).
Using an otoscope to confirm the earplug has passed the second bend of the ear canal.

Correct answer: Asking the employee if their own voice sounds deeper or louder.

A well-known subjective check for a good earplug fit is the occlusion effect. When the ear canal is properly sealed, the user's own voice will sound louder, deeper, or different to them. This indicates a good seal has been achieved. The other methods listed are objective (quantitative fit-testing, visual inspection, otoscopy), not subjective feedback from the wearer.

Question 10: A sound level meter's A-weighting network is designed to be most useful for hearing conservation purposes because it:

filters out all frequencies below 1000 Hz.
approximates the frequency response of the human ear to moderate sound levels. (Correct answer)
provides a flat response across all audible frequencies.
measures peak impulse noises accurately.

Correct answer: approximates the frequency response of the human ear to moderate sound levels.

The A-weighting scale filters sound to mimic how the human ear perceives loudness at different frequencies, being less sensitive to very low and very high frequencies. [18, 27] This makes it the best predictor of the potential for noise to cause hearing damage and is the standard weighting used for occupational noise exposure measurements, such as the OSHA Action Level and PEL. [24]

Question 11: What does a flat audiometric configuration across all frequencies most likely indicate?

Conductive hearing loss or a middle ear disorder (Correct answer)
Noise-induced hearing loss from impulse noise
Normal hearing with equipment calibration error
Ototoxic medication exposure

Correct answer: Conductive hearing loss or a middle ear disorder

A flat audiometric pattern with roughly equal loss across frequencies is more characteristic of conductive hearing loss or middle ear pathology rather than noise-induced hearing loss.

Question 12: What is the function of the ossicular chain in the middle ear?

To convert sound waves into electrical nerve impulses
To produce the endolymph fluid in the inner ear
To amplify and transmit sound vibrations from the tympanic membrane to the oval window (Correct answer)
To equalize air pressure between middle ear and environment

Correct answer: To amplify and transmit sound vibrations from the tympanic membrane to the oval window

The three ossicles form a mechanical lever system that amplifies sound vibrations approximately 25-30 dB as they transfer energy from the tympanic membrane to the oval window.

Question 13: Which type of hearing protection device is typically most effective at reducing noise exposure?

Cotton balls
Earplugs
Both earplugs and ear muffs used together (Correct answer)
Ear muffs

Correct answer: Both earplugs and ear muffs used together

Using both earplugs and earmuffs concurrently, known as "double hearing protection," provides the highest level of noise attenuation. This combination offers superior protection compared to using either device alone, as it creates a more comprehensive barrier against sound waves. It is recommended for environments with extremely high noise levels.

Question 14: What is 'bioacoustic simulation' and how is it used in audiometric equipment quality control?

A method of testing audiometric booth construction materials
A hearing aid fitting technique
An electronic device that simulates human hearing responses to verify audiometric system accuracy (Correct answer)
A medical procedure to test cochlear function

Correct answer: An electronic device that simulates human hearing responses to verify audiometric system accuracy

A bioacoustic simulator is an electronic device that receives acoustic signals and generates responses simulating a person with known hearing thresholds. It is used to verify the accuracy of the complete audiometric system including the audiometer, transducers, and booth.

Question 15: Which of the following is NOT a responsibility of a CAOHC-certified Occupational Hearing Conservationist (OHC) in the audiometric testing process?

Calculating a Standard Threshold Shift (STS).
Diagnosing the cause of a hearing loss. (Correct answer)
Instructing the employee on the testing procedure.
Conducting daily functional checks of the audiometer.

Correct answer: Diagnosing the cause of a hearing loss.

The scope of practice for an OHC does not include diagnosing medical conditions or the cause of hearing loss. That responsibility lies with a physician or audiologist. OHCs are trained to perform valid testing, identify potential problems (like an STS) for review by the Professional Supervisor, perform daily checks, and properly instruct the person being tested.

Question 16: What comprehensive approach to program evaluation does CAOHC recommend for OHCs?

A multi-component evaluation addressing all program elements including monitoring, audiometry, protection, training, and recordkeeping (Correct answer)
Evaluation of only the audiometric testing component
No specific evaluation approach is recommended by CAOHC
Evaluation based solely on OSHA compliance status

Correct answer: A multi-component evaluation addressing all program elements including monitoring, audiometry, protection, training, and recordkeeping

CAOHC recommends a comprehensive evaluation approach that assesses every component of the hearing conservation program. Each element — noise monitoring, audiometric testing, hearing protection, training, and recordkeeping — must function effectively for the overall program to prevent hearing loss.

Question 17: What is the Noise Reduction Rating (NRR)?

A measure of how well employees can hear instructions
A measure of the total noise level in the environment
The decibel level at which hearing protection becomes necessary
A rating that indicates the effectiveness of a hearing protection device in reducing noise (Correct answer)

Correct answer: A rating that indicates the effectiveness of a hearing protection device in reducing noise

The Noise Reduction Rating (NRR) is a standardized measure used to indicate the potential effectiveness of a hearing protection device in reducing noise exposure. It is expressed in decibels (dB) and represents the amount of noise reduction an average user can expect when the device is worn correctly. A higher NRR signifies greater noise attenuation.

Question 18: What is the essential connection between program evaluation and worker hearing health outcomes?

There is no connection between evaluation activities and worker outcomes
Worker outcomes are determined solely by noise levels, not program quality
Evaluation only benefits program administrators, not workers
Evaluation identifies program weaknesses before they result in irreversible hearing loss, enabling preventive corrective action (Correct answer)

Correct answer: Evaluation identifies program weaknesses before they result in irreversible hearing loss, enabling preventive corrective action

Program evaluation is the mechanism that connects program activities with worker outcomes. By identifying weaknesses before they cause permanent hearing damage, evaluation enables proactive correction that directly protects workers' hearing health.

Question 19: What are the three main categories of hearing protection devices?

Active noise canceling headphones, earmuffs, and surgical masks
Earplugs, helmets, and face shields
Custom earplugs, disposable earplugs, and noise barriers
Earplugs, earmuffs, and semi-insert (canal cap) devices (Correct answer)

Correct answer: Earplugs, earmuffs, and semi-insert (canal cap) devices

The three main categories are earplugs (inserted into the ear canal), earmuffs (covering the entire ear), and semi-insert devices (sealed against the canal entrance).

Question 20: What is the purpose of the 'professional review' of audiometric records required by OSHA?

To approve the employer's noise monitoring methodology
To certify the audiometric booth for another year of use
To verify that the OHC used the correct audiometer brand
To have a qualified professional evaluate each audiogram for STS and determine if referral or follow-up is needed (Correct answer)

Correct answer: To have a qualified professional evaluate each audiogram for STS and determine if referral or follow-up is needed

OSHA requires that audiograms be reviewed by a qualified professional (audiologist, otolaryngologist, or other physician) who evaluates each record for STS, considers the need for further evaluation or referral, and determines appropriate follow-up actions.

Question 21: Which organization accredits OHC training courses and oversees the certification of Occupational Hearing Conservationists in the US?

ASHA
NIOSH
OSHA
CAOHC (Correct answer)

Correct answer: CAOHC

CAOHC (Council for Accreditation in Occupational Hearing Conservation) accredits OHC training programs and administers the certification process.

Question 22: What is the maximum permissible ambient noise level in an audiometric test booth at 1000 Hz according to OSHA?

50 dB SPL
15 dB SPL
25 dB SPL
40 dB SPL (Correct answer)

Correct answer: 40 dB SPL

OSHA specifies maximum permissible ambient noise levels for audiometric test rooms, with 40 dB SPL at 1000 Hz per Appendix D of 29 CFR 1910.95.

Question 23: Which engineering control technique reduces noise by preventing vibration transmission between machinery and structures?

Administrative rotation of workers
Increasing the distance between workers and equipment
Acoustic absorption panels on walls
Vibration isolation using resilient mounts or pads (Correct answer)

Correct answer: Vibration isolation using resilient mounts or pads

Vibration isolation mounts prevent mechanical vibrations from machinery from being transmitted to structures that can radiate noise.

Question 24: What is the primary purpose of conducting an annual hearing conservation program review?

To purchase new audiometric equipment
To recertify all OHC technicians
To evaluate program effectiveness and identify improvements (Correct answer)
To update employee rosters

Correct answer: To evaluate program effectiveness and identify improvements

Annual HCP reviews assess overall program effectiveness, identify deficiencies, and ensure continued compliance with regulatory requirements.

Question 25: What is the final message about program evaluation for CAOHC-certified OHCs?

The OHC's role in evaluation is limited to collecting audiograms
Program evaluation is optional and only matters during audits
Systematic evaluation is essential to ensuring the program achieves its mission of preventing hearing loss, and the OHC is central to this process (Correct answer)
Modern technology has eliminated the need for human involvement in program evaluation

Correct answer: Systematic evaluation is essential to ensuring the program achieves its mission of preventing hearing loss, and the OHC is central to this process

CAOHC emphasizes that systematic program evaluation is not optional but essential to fulfilling the hearing conservation mission. The OHC, with daily access to workers, equipment, and program operations, is uniquely positioned to drive the evaluation process and champion resulting improvements.

Question 26: What is the primary function of hearing protection devices (HPDs)?

To reduce noise exposure to safe levels (Correct answer)
To improve overall job performance
To enhance communication among workers
To eliminate all noise in the workplace

Correct answer: To reduce noise exposure to safe levels

Hearing Protection Devices (HPDs) are designed to attenuate, or reduce, the intensity of sound reaching the wearer's ears. Their primary function is not to eliminate all noise, but to lower hazardous noise levels to a point where they are safe for hearing. This prevents noise-induced hearing loss in environments where noise cannot be controlled by engineering or administrative methods alone.

Question 27: What is acoustic trauma and how does it differ from chronic noise-induced hearing loss?

Acoustic trauma is sudden damage from a single intense event; chronic NIHL develops gradually from prolonged exposure (Correct answer)
They are the same condition at different stages
Acoustic trauma only affects one ear while chronic NIHL affects both
Acoustic trauma causes low-frequency loss while chronic NIHL causes high-frequency loss

Correct answer: Acoustic trauma is sudden damage from a single intense event; chronic NIHL develops gradually from prolonged exposure

Acoustic trauma results from a single exposure to extremely intense sound causing immediate damage, while chronic NIHL develops over months or years.

Question 28: How should the OHC approach communication with a worker who uses hearing aids that do not seem to be functioning properly?

Confiscate the hearing aids and provide earplugs instead
Ignore the issue since hearing aids are the worker's personal responsibility
Attempt to repair the hearing aids themselves
Note the observation, gently ask the worker if they are having trouble with their hearing aids, and suggest consulting their audiologist (Correct answer)

Correct answer: Note the observation, gently ask the worker if they are having trouble with their hearing aids, and suggest consulting their audiologist

The OHC should tactfully bring up the observation and suggest the worker consult their hearing aid provider. While hearing aids are personal devices outside the OHC's technical scope, alerting the worker to a possible malfunction demonstrates care and may improve their communication and safety.

Question 29: A hearing conservation program is required by OSHA when employee noise exposures reach or exceed which level?

80 dBA TWA
90 dBA TWA
85 dBA TWA (Correct answer)
95 dBA TWA

Correct answer: 85 dBA TWA

OSHA mandates HCP implementation when any employee's noise exposure equals or exceeds the 85 dBA action level.

Question 30: An OHC is explaining an annual audiogram to an employee who has no significant threshold shift. Which statement is the most appropriate and clear way to communicate the results?

"Your audiometric thresholds at 500 through 6000 Hz show no statistically significant deviation from your established baseline, indicating your hearing protection is effective."
"You passed the test. There's nothing to worry about."
"This test shows that your hearing hasn't changed much since your first test here. That's great news and suggests your earplugs are working well for you." (Correct answer)
"We're not allowed to discuss the specific results with you; you'll have to wait for the report from the professional supervisor."

Correct answer: "This test shows that your hearing hasn't changed much since your first test here. That's great news and suggests your earplugs are working well for you."

This statement is clear, positive, uses layperson's terms ("hasn't changed much"), reinforces the purpose of the test, and links the good result to the employee's protective action (earplugs are working). Option B is filled with jargon. Option C is incorrect, as OHCs can and should provide basic explanations. Option D is overly simplistic and misses a key educational opportunity to reinforce positive behaviors.

Question 31: How does noise-induced hearing loss differ from age-related hearing loss?

Presbycusis only affects low frequencies
Noise-induced shows a notch at 4000 Hz with recovery at 8000 Hz; presbycusis shows a gradual high-frequency slope without recovery (Correct answer)
Noise-induced loss is always bilateral while presbycusis affects only one ear
They produce identical audiometric patterns

Correct answer: Noise-induced shows a notch at 4000 Hz with recovery at 8000 Hz; presbycusis shows a gradual high-frequency slope without recovery

The key distinction is the notch pattern with 8000 Hz recovery versus gradual slope without recovery.

Question 32: According to OSHA regulations (29 CFR 1910.95), a Standard Threshold Shift (STS) is defined as a change in hearing threshold, relative to the baseline audiogram, of an average of:

10 dB or more at 2000, 3000, and 4000 Hz in either ear. (Correct answer)
10 dB or more at 1000, 2000, and 3000 Hz in either ear.
15 dB or more at 2000, 3000, and 4000 Hz in either ear.
15 dB or more at 500, 1000, and 2000 Hz in both ears.

Correct answer: 10 dB or more at 2000, 3000, and 4000 Hz in either ear.

OSHA's definition of a Standard Threshold Shift is very specific. It is a change in hearing threshold of an average of 10 decibels (dB) or more at the frequencies of 2000, 3000, and 4000 Hz in either ear when comparing the current audiogram to the baseline audiogram.

Question 33: How often must hearing conservation training be provided under OSHA?

Only at initial hire
Annually (Correct answer)
Every five years
Every two years

Correct answer: Annually

OSHA requires that hearing conservation training be repeated annually for all employees in the HCP.

Question 34: How should an HCP accommodate workers on rotating shifts?

Only day-shift workers need HCP services
By ensuring testing, training, and protector access are available across all shifts (Correct answer)
Night-shift workers are exempt from noise monitoring
Rotating shift workers should be tested only on their final shift

Correct answer: By ensuring testing, training, and protector access are available across all shifts

All HCP services must be accessible to workers on all shifts.

Question 35: What is the primary role of the tympanic membrane (eardrum) in the hearing process?

It converts airborne sound pressure waves into mechanical vibrations (Correct answer)
It filters high-frequency sounds before they enter the cochlea
It amplifies low-frequency sounds through resonance
It equalizes pressure between the middle and outer ear

Correct answer: It converts airborne sound pressure waves into mechanical vibrations

The tympanic membrane vibrates in response to incoming sound pressure waves, converting acoustic energy into mechanical motion that is then transmitted to the ossicular chain. This transduction step bridges the outer and middle ear.

Question 36: What is the primary purpose of an audiometric test booth?

To provide privacy for the worker during testing only
To reduce ambient noise to levels that allow valid hearing threshold measurements (Correct answer)
To amplify the audiometric test signals
To eliminate the need for calibrated audiometers

Correct answer: To reduce ambient noise to levels that allow valid hearing threshold measurements

The audiometric booth provides a controlled acoustic environment with reduced ambient noise. Without adequate noise reduction, background noise can mask test signals and result in falsely elevated hearing thresholds.

Question 37: How should an OHC handle a situation where the audiometric booth meets ANSI standards for supra-aural earphones but not for insert earphones?

This situation is impossible since insert earphones have more lenient requirements
Switch to bone conduction testing only
Test outside the booth where ambient noise limits do not apply
Use supra-aural earphones with the higher ANSI noise limits, or reduce ambient noise to meet the stricter insert earphone requirements (Correct answer)

Correct answer: Use supra-aural earphones with the higher ANSI noise limits, or reduce ambient noise to meet the stricter insert earphone requirements

Insert earphones have different (generally more lenient) ambient noise requirements because they provide more attenuation. However, if the question states the booth does not meet insert earphone standards, the OHC should use supra-aural earphones (which have higher allowable noise limits) or reduce booth noise.

Question 38: Which professional is qualified to perform the problem audiogram review under OSHA regulations?

A trained audiometric technician without supervision
An audiologist or physician (Correct answer)
The hearing conservation program administrator
Any certified occupational health nurse

Correct answer: An audiologist or physician

OSHA requires that problem audiograms be reviewed by an audiologist, otolaryngologist, or other qualified physician who can make clinical determinations about hearing status.

Question 39: Along the basilar membrane within the cochlea, where are high-frequency sounds preferentially detected?

In the middle section called the scala media
At the apex (helicotrema end)
Uniformly distributed along the entire length
At the base near the oval window (Correct answer)

Correct answer: At the base near the oval window

The basilar membrane is tonotopically organized. High frequencies cause maximum displacement near the base (stiff, narrow region near the oval window), while low frequencies cause maximum displacement near the apex (flexible, wider region). This spatial mapping is fundamental to frequency discrimination.

Question 40: Before taking noise measurements, what must be done to ensure accuracy?

Calibrate using an acoustic calibrator at the beginning and end of measurements (Correct answer)
Hold the meter at arm length and verify the display
Compare readings to a nearby dosimeter
Simply replace the batteries

Correct answer: Calibrate using an acoustic calibrator at the beginning and end of measurements

Sound level meters must be field-calibrated before and after each measurement session using an acoustic calibrator.

Question 41: What is the purpose of noise contour mapping in a workplace?

To create a visual representation of noise levels across the facility for identifying high-exposure areas (Correct answer)
To measure each individual worker personal noise exposure
To calculate the building acoustic insulation rating
To determine the frequency content of machinery noise

Correct answer: To create a visual representation of noise levels across the facility for identifying high-exposure areas

Noise contour maps show spatial distribution of noise levels, helping identify areas where workers need protection.

Question 42: What is the most common cause of occupational hearing loss?

Lack of sleep
Poor nutrition
Overuse of earplugs
Prolonged exposure to high levels of noise (Correct answer)

Correct answer: Prolonged exposure to high levels of noise

Occupational hearing loss is predominantly caused by repeated or prolonged exposure to excessive noise levels in the workplace. High-intensity sound damages the delicate hair cells in the inner ear, leading to permanent hearing impairment. This makes noise control and hearing conservation programs vital for worker safety.

Question 43: When comparing annual audiograms to baseline, which frequencies are included in the OSHA STS calculation?

500, 1000, and 2000 Hz
2000, 3000, and 4000 Hz (Correct answer)
1000, 2000, 3000, and 4000 Hz
3000, 4000, 6000, and 8000 Hz

Correct answer: 2000, 3000, and 4000 Hz

The OSHA standard threshold shift calculation uses the average of threshold changes at 2000, 3000, and 4000 Hz.

Question 44: What is the maximum permissible ambient noise level for the 500 Hz octave band in an audiometric test room according to ANSI S3.1?

25 dB SPL
50 dB SPL
40 dB SPL (Correct answer)
60 dB SPL

Correct answer: 40 dB SPL

ANSI S3.1 specifies maximum permissible ambient noise levels (MPANLs) for audiometric testing rooms. For the 500 Hz octave band, the MPANL is 40 dB SPL when testing to 0 dB HL using supra-aural earphones.

Question 45: How should the OHC use program evaluation data to prepare for the annual report to the supervising professional?

Compile key metrics, highlight trends, identify concerns, and propose specific recommendations for professional review (Correct answer)
The OHC does not prepare reports for the supervising professional
Wait for the professional to request specific information
Submit raw data without analysis or interpretation

Correct answer: Compile key metrics, highlight trends, identify concerns, and propose specific recommendations for professional review

The OHC should compile evaluated data including STS rates, compliance metrics, equipment status, training outcomes, and identified concerns into a structured report. Adding practical observations and specific recommendations leverages the OHC's field expertise to inform the professional's review.

Question 46: How often must OSHA-mandated audiometric testing be performed for workers in a hearing conservation program?

Every 6 months
Only at hire and termination
Annually (Correct answer)
Every 2 years

Correct answer: Annually

OSHA requires annual audiometric testing for all workers included in the hearing conservation program to monitor for changes in hearing thresholds.

Question 47: Which activity is OUTSIDE the scope of an OHC's practice?

Performing daily biological calibration checks
Interpreting audiograms to provide a medical diagnosis (Correct answer)
Fitting and checking hearing protection devices
Administering pure tone audiometric tests

Correct answer: Interpreting audiograms to provide a medical diagnosis

Medical interpretation and diagnosis from audiometric results is beyond OHC scope and must be performed by a licensed audiologist or physician.

Question 48: The Federal Railroad Administration (FRA) Noise Exposure regulation (49 CFR Part 227) requires that hearing conservation programs be implemented for certain railroad employees. What is the continuous noise exposure action level that triggers this requirement?

A 12-hour TWA of 90 dBA
An 8-hour TWA of 85 dBA
A 12-hour TWA of 85 dBA
An 8-hour TWA of 90 dBA (Correct answer)

Correct answer: An 8-hour TWA of 90 dBA

Unlike OSHA's general industry standard which has an action level of 85 dBA, the FRA's action level for implementing a hearing conservation program, as stated in 49 CFR 227, is an 8-hour TWA of 90 dBA. This is a key distinction between the two regulations.

Question 49: An employee works an 8-hour shift in an area with a constant noise level of 85 dBA. After work, they report a temporary ringing in their ears and a feeling of muffled hearing. This condition is best described as:

Conductive Hearing Loss
Acoustic Trauma
Permanent Threshold Shift (PTS)
Temporary Threshold Shift (TTS) (Correct answer)

Correct answer: Temporary Threshold Shift (TTS)

Temporary Threshold Shift (TTS) is a short-term decrease in hearing sensitivity that can occur after exposure to loud noise. It is often accompanied by tinnitus (ringing in the ears). Hearing typically returns to normal after a period of rest away from the noise. Permanent Threshold Shift (PTS) is a non-recoverable hearing loss. Acoustic trauma results from a single, intense noise event. Conductive hearing loss involves a problem with the outer or middle ear.

Question 50: Under OSHA's HCP requirements, how soon after initial assignment to noise-exposed work must a baseline audiogram be obtained?

Within 12 months
Within 1 month
Within 3 months
Within 6 months (Correct answer)

Correct answer: Within 6 months

OSHA requires the baseline audiogram to be obtained within 6 months of an employee's first exposure at or above the action level.

Question 51: What is the role of the supervising professional in a hearing conservation program?

An audiologist or physician who reviews audiograms, identifies problem cases, and provides clinical oversight (Correct answer)
An OSHA inspector who conducts annual audits
A safety manager who purchases hearing protectors
A noise control engineer who designs modifications

Correct answer: An audiologist or physician who reviews audiograms, identifies problem cases, and provides clinical oversight

The supervising professional provides clinical oversight including reviewing audiometric results and determining STS significance.

Question 52: What is the purpose of baseline audiometric testing in a hearing conservation program?

To establish a reference for future hearing tests (Correct answer)
To determine employees' job satisfaction
To assess the effectiveness of hearing protection devices
To diagnose non-work-related health issues

Correct answer: To establish a reference for future hearing tests

Baseline audiometric testing provides an initial record of an employee's hearing ability before significant noise exposure or at the start of their employment in a noisy environment. This baseline is crucial for comparison with subsequent annual audiograms. It allows for the identification of any significant shifts in hearing, indicating potential noise-induced hearing loss.

Question 53: How often must audiometers used in occupational hearing conservation programs receive exhaustive calibration?

Only when purchased new
At least annually (Correct answer)
Monthly
Every 5 years

Correct answer: At least annually

OSHA requires exhaustive (electroacoustic) calibration of audiometers at least annually. This comprehensive calibration verifies that the audiometer's output meets ANSI specifications across all frequencies and intensity levels.

CAOHC Occupational Hearing Conservationist Certification Exam

The CAOHC OHC certification exam validates competency in occupational hearing conservation, covering audiometric testing, noise measurement, hearing protection, and program administration under OSHA standards.

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