ABA ABA Hearing Conservation & Occupational Audiology

Question 1

According to OSHA's Hearing Conservation Amendment (29 CFR 1910.95), the action level at which a hearing conservation program must be implemented is:

Accepted Answer

85 dBA TWA8

Answer

OSHA requires employers to implement a hearing conservation program when workers are exposed to a time-weighted average of 85 dBA or more over an 8-hour workday.

Question 2

OSHA's Permissible Exposure Limit (PEL) for occupational noise is based on which exchange rate?

Accepted Answer

5 dB exchange rate

Answer

OSHA uses a 5 dB exchange rate, meaning the allowable exposure time halves for every 5 dB increase in noise level above 90 dBA.

Question 3

A standard threshold shift (STS) under OSHA's hearing conservation standard is defined as a change in hearing threshold averaging how many dB in either ear at 2000, 3000, and 4000 Hz?

Accepted Answer

15 dB

Answer

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

Question 4

Which audiometric pattern is most characteristic of noise-induced hearing loss (NIHL)?

Accepted Answer

Notch at 4000 Hz with recovery at 8000 Hz

Answer

NIHL typically presents as a sensorineural notch at 4000 Hz (sometimes 3000–6000 Hz) with relative recovery at 8000 Hz, reflecting the cochlea's frequency-place map and mechanical resonance.

Question 5

The Noise Reduction Rating (NRR) is used to estimate hearing protector performance. According to OSHA's method, the real-world noise attenuation is calculated by deducting 7 from the NRR and then:

Accepted Answer

Dividing the result by 2 when using A-weighted measurements

Answer

When using A-weighted sound levels, OSHA's method requires dividing (NRR − 7) by 2 to account for real-world variability in hearing protector performance.

(ABA) American Board of Audiology Practice Test

(ABA) American Board of Audiology Practice Test

ABA ABA Hearing Conservation & Occupational Audiology