CHST Noise Exposure and Hearing Conservation Programs 4

Question 1

Using OSHA's method for estimating A-weighted attenuation, what is the estimated protected exposure for a worker at 100 dBA wearing earplugs with an NRR of 29?

Accepted Answer

89 dBA

Answer

OSHA's method subtracts 7 dB from the NRR and halves it: (29-7)/2 = 11, so 100-11 = 89 dBA.

Question 2

When earplugs and earmuffs are worn together, OSHA guidance estimates protection by adding how much to the higher NRR?

Accepted Answer

5 dB

Answer

Dual protection is estimated by adding 5 dB to the attenuation of the higher-rated device.

Question 3

To what level must hearing protectors attenuate exposure for an employee who has experienced an STS?

Accepted Answer

85 dBA TWA

Answer

For employees with an STS, protectors must reduce exposure to 85 dBA TWA or below.

Question 4

Which factor most commonly reduces real-world hearing protector performance below the labeled NRR?

Accepted Answer

Improper fit and inconsistent wearing

Answer

Poor insertion, bad seals, and removal during exposure sharply reduce actual attenuation.

Question 5

A worker wearing safety glasses with thick temples and earmuffs is likely to experience what?

Accepted Answer

Reduced attenuation from a broken seal

Answer

Eyewear temples break the earmuff cushion seal, allowing noise leakage.

CHST - Construction Health and Safety Technician Practice Test

CHST - Construction Health and Safety Technician Practice Test

CHST Noise Exposure and Hearing Conservation Programs 4