Mixed Deck — All CAOHC Topics Flashcards

What is the purpose of masking in audiometric testing?

Answer: To prevent the non-test ear from responding to signals presented to the test ear

Masking introduces noise to the non-test ear to eliminate cross-hearing, ensuring that thresholds measured truly represent the test ear sensitivity.

A company is acquired by a new owner. What is the successor employer's responsibility regarding the audiometric records and baseline audiograms from the previous owner?

Answer: They must receive and retain the records, continuing to use the established baselines for STS comparison.

According to OSHA regulation 29 CFR 1910.95(m)(5), when an employer ceases business, they must transfer all required records to the successor employer. The successor employer is then required to retain these records and should continue to use the established baseline audiograms for comparison unless there is a valid reason to question their accuracy.

What is the primary role of a CAOHC-certified Occupational Hearing Conservationist (OHC)?

Answer: To conduct audiometric testing and assist in administering hearing conservation programs

OHCs conduct pure tone audiometric testing and assist with HCP administration under the supervision of a licensed audiologist or physician.

What is the OSHA-defined standard threshold shift (STS)?

Answer: An average shift of 10 dB or more at 2000, 3000, and 4000 Hz in either ear

OSHA defines STS as an average change of 10 dB or more at 2000, 3000, and 4000 Hz in either ear compared to the baseline audiogram.

A worker you are fitting for roll-down foam earplugs successfully demonstrates the 'roll' and 'pull' steps but complains the plug feels like it's 'hitting a wall' and won't go in further. Upon removal, the earplug is bent in a U-shape. This most likely indicates:

Answer: The worker is not pulling their pinna in the correct direction to straighten the ear canal.

When an earplug bends upon insertion, it often means it is hitting the wall of the ear canal instead of following its path. While ear canal size can be a factor, the primary cause is often an improperly straightened ear canal. The direction of the pinna pull (up and back, or sometimes straight out) is individual. The OHC should observe the worker's ear and coach them on which pull direction most effectively opens their specific ear canal to allow for deeper, correct insertion.

Under OSHA, how must hearing loss be recorded on the OSHA 300 Log?

Answer: When an STS is confirmed and the average hearing level at 2000, 3000, and 4000 Hz reaches 25 dB or more

OSHA recording criteria require both a confirmed STS AND an average hearing level of 25 dB HL or more at 2000, 3000, and 4000 Hz.

What is OSHA's definition of a Standard Threshold Shift (STS)?

Answer: An average change of 10 dB or more at 2000, 3000, and 4000 Hz in either ear

OSHA defines STS as an average shift of 10 dB or more at the frequencies of 2000, 3000, and 4000 Hz in either ear relative to the baseline audiogram. This specific definition focuses on the frequencies most affected by occupational noise.

What is a 'sentinel event' in the context of ototoxic exposure monitoring within a hearing conservation program?

Answer: An unexpected threshold shift in a worker that signals potential ototoxic exposure to the wider workforce

A sentinel event is an unexpected audiometric finding in one worker that may indicate a broader ototoxic exposure problem affecting others in the same work area. It triggers investigation of workplace chemical exposure conditions.

What is the role of the program administrator in a hearing conservation program?

Answer: To coordinate all program elements including monitoring, testing, training, protector provision, and recordkeeping

The program administrator coordinates the overall hearing conservation program, ensuring all required elements are implemented and maintained.

What is the most common cause of occupational hearing loss?

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.

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:

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.

According to standard audiometric testing protocol, testing of frequencies should begin at which Hz?

Answer: 1000 Hz

Standard protocol begins testing at 1000 Hz because it is a reliable frequency and is retested later to check for test-retest reliability.

What does OSHA require regarding the fit and effectiveness of hearing protectors provided to workers?

Answer: Employers must ensure protectors are properly fitted and workers are trained in their correct use

OSHA requires that employers ensure hearing protectors fit properly and that workers are trained in correct insertion and use. A protector that is not properly fitted provides significantly less protection than its rated NRR suggests.

How long must employers retain employee audiometric test records under OSHA's HCP standard?

Answer: For the duration of employment plus 30 years

OSHA requires audiometric records to be retained for the duration of employment plus 30 years due to the latency of noise-induced hearing loss.

What is the role of pharmacokinetics in understanding ototoxic chemical exposure?

Answer: It describes how the body absorbs, distributes, metabolizes, and excretes the chemical, affecting cochlear exposure duration

Pharmacokinetics describes the absorption, distribution, metabolism, and excretion of chemicals in the body. Understanding these processes helps predict how long and at what concentration an ototoxic agent will be present in the cochlea.

What is the minimum frequency requirement for audiometric testing under OSHA's Hearing Conservation Amendment?

Answer: Annually

OSHA requires annual audiometric testing for workers exposed to noise at or above the 85 dBA action level.

What is the purpose of the daily biological calibration check of an audiometer?

Answer: To verify the audiometer is functioning within acceptable limits by testing a person with known, stable hearing

Daily biological calibration involves testing a person with known, stable hearing thresholds. If results deviate by more than 10 dB from established levels at any frequency, the audiometer requires service before being used for testing.

Which type of hearing protector is generally most appropriate for workers who must frequently enter and exit noisy areas?

Answer: Banded earplugs or earmuffs that can be quickly removed and replaced

Banded earplugs and earmuffs are ideal for intermittent noise exposure because they can be quickly put on and removed.

What is the primary advantage of electronic hearing protectors in occupational settings?

Answer: They allow normal conversation and warning signals while blocking hazardous noise levels

Electronic protectors pass through ambient sounds at safe levels while limiting amplification when noise exceeds a threshold.

What is the primary purpose of an audiometric test booth?

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.