Free CAOHC Audiogram Review and STS Questions and Answers 1 — Questions and Answers
Question 1: 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:
- 15 dB or more at 2000, 3000, and 4000 Hz in either ear.
- 10 dB or more at 1000, 2000, and 3000 Hz in either ear.
- 10 dB or more at 2000, 3000, and 4000 Hz in either ear. (Correct answer)
- 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 2: An employee's annual audiogram shows a confirmed STS. The employer must notify the employee in writing within how many days of this determination?
- 14 days
- 21 days (Correct answer)
- 30 days
- 45 days
Correct answer: 21 days
OSHA requires employers to notify employees in writing within 21 days of the determination that a Standard Threshold Shift (STS) has occurred.
Question 3: A Certified Occupational Hearing Conservationist (COHC) identifies an audiogram with a potential STS and significant differences between ears. Which of the following is the most appropriate next step for the COHC?
- Independently diagnose the cause of the hearing loss.
- Immediately revise the employee's baseline audiogram.
- Inform the employee they have permanent work-related hearing loss.
- Refer the problem audiogram to the Professional Supervisor for review. (Correct answer)
Correct answer: Refer the problem audiogram to the Professional Supervisor for review.
The scope of practice for a COHC includes identifying problem audiograms, but the review and determination of next steps, such as the need for further evaluation or diagnosis, must be done by a Professional Supervisor (an audiologist, otolaryngologist, or other physician).
Question 4: An annual audiogram reveals an STS. To determine if the shift is persistent, the employer may perform a retest. This retest should be conducted within:
- 10 days of the annual test.
- 90 days of the annual test.
- 60 days of the annual test.
- 30 days of the annual test. (Correct answer)
Correct answer: 30 days of the annual test.
OSHA allows for a retest to be performed within 30 days of the annual audiogram to confirm if the STS is persistent. If the retest does not confirm the STS, it does not need to be recorded.
Question 5: When determining if a Standard Threshold Shift (STS) has occurred, an employer may apply age corrections to the current audiogram. However, age correction is NOT permitted when determining if:
- a baseline revision is needed.
- the employee needs retraining on hearing protection.
- the employee's total hearing level is 25 dB or more above audiometric zero. (Correct answer)
- a retest is required within 30 days.
Correct answer: the employee's total hearing level is 25 dB or more above audiometric zero.
OSHA regulations specifically state that while age correction is optional for calculating the 10 dB average shift (the STS itself), it cannot be used when determining if the employee's total hearing level meets the second part of the recordability criteria: an average hearing level of 25 dB or more above audiometric zero at 2000, 3000, and 4000 Hz.
Question 6: A new employee at a manufacturing plant has a baseline audiogram that shows a pre-existing hearing loss. Six years later, an annual audiogram shows an additional 12 dB average shift at 2000, 3000, and 4000 Hz. The Professional Supervisor determines the STS is work-related and persistent. What is the appropriate action regarding the employee's baseline audiogram?
- The original baseline must be used for all future comparisons.
- A new baseline can be established using the results of the latest annual audiogram. (Correct answer)
- The baseline should be deleted as it is no longer valid.
- The employee must be removed from the hearing conservation program.
Correct answer: A new baseline can be established using the results of the latest annual audiogram.
When a persistent STS is identified, the Professional Supervisor can revise the baseline audiogram. The current audiogram that shows the STS may be used as the revised baseline for future comparisons. This prevents the same hearing loss from being repeatedly identified as a new STS on subsequent tests.
Free CAOHC Audiogram Review and STS Questions and Answers 1
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: