CHST Noise Exposure and Hearing Conservation Programs 3

Question 1

A standard threshold shift (STS) is defined as an average change from baseline of how many dB at 2000, 3000, and 4000 Hz in either ear?

Accepted Answer

10 dB or more

Answer

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

Question 2

For an STS to be recordable on the OSHA 300 log, the employee's average hearing level at 2000, 3000, and 4000 Hz must also be at least how far above audiometric zero?

Accepted Answer

25 dB

Answer

Under 1904.10, an STS is recordable when the average hearing level is also 25 dB or more above audiometric zero in the same ear.

Question 3

How many hours of quiet should precede a baseline audiogram?

Accepted Answer

14 hours

Answer

Baseline testing must be preceded by at least 14 hours without workplace noise exposure, which hearing protectors can satisfy.

Question 4

Within what time frame must an employer establish a valid baseline audiogram after an employee's first exposure at or above the action level (without a mobile test van)?

Accepted Answer

6 months

Answer

OSHA requires a baseline audiogram within 6 months of first exposure at or above the action level.

Question 5

After an STS is confirmed, the employer must notify the employee in writing within how many days?

Accepted Answer

21 days

Answer

OSHA requires written notification within 21 days of determining an STS.

CHST - Construction Health and Safety Technician Practice Test

CHST - Construction Health and Safety Technician Practice Test

CHST Noise Exposure and Hearing Conservation Programs 3