CHST Noise Exposure and Hearing Conservation Programs 5

Question 1

In a free field, doubling the distance from a point noise source reduces the sound pressure level by approximately how much?

Accepted Answer

6 dB

Answer

The inverse square law gives about a 6 dB drop per doubling of distance from a point source.

Question 2

Noise-induced hearing loss typically first appears as a 'notch' on the audiogram at which frequency?

Accepted Answer

4000 Hz

Answer

Noise damage characteristically produces a dip near 4000 Hz with recovery at 8000 Hz.

Question 3

Which weighting network and meter response does OSHA specify for measuring noise for compliance?

Accepted Answer

A-weighting, slow response

Answer

OSHA noise levels are measured on the A-weighted scale at slow response.

Question 4

Which chemical exposure is recognized as ototoxic and may worsen hearing loss when combined with noise?

Accepted Answer

Toluene

Answer

Solvents such as toluene, styrene, and xylene are ototoxic and act synergistically with noise.

Question 5

NIOSH's recommended exposure limit for noise differs from OSHA's PEL in that it uses which criteria?

Accepted Answer

85 dBA with a 3 dB exchange rate

Answer

NIOSH recommends 85 dBA as an 8-hour TWA with a more protective 3 dB exchange rate.

CHST - Construction Health and Safety Technician Practice Test