Noise Measurement and Control Flashcards
6 cards from real CAOHC practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Noise Measurement and Control flashcards as text
What does a noise dose of 200% indicate about a worker exposure?
Answer: The worker received twice the maximum allowable daily noise exposure
A noise dose of 200% means the worker was exposed to twice the permissible noise dose, equivalent to approximately 95 dBA TWA.
What is the purpose of noise contour mapping in a workplace?
Answer: To create a visual representation of noise levels across the facility for identifying high-exposure areas
Noise contour maps show spatial distribution of noise levels, helping identify areas where workers need protection.
Which engineering control technique reduces noise by preventing vibration transmission between machinery and structures?
Answer: Vibration isolation using resilient mounts or pads
Vibration isolation mounts prevent mechanical vibrations from machinery from being transmitted to structures that can radiate noise.
What is the threshold level setting on a noise dosimeter and why is it important?
Answer: The minimum sound level below which the dosimeter does not accumulate dose, set at 80 dBA for OSHA
The threshold is the minimum level the dosimeter includes in its dose integration. OSHA specifies 80 dBA for hearing conservation measurements.
How does doubling the distance from a point noise source affect the sound level in a free field?
Answer: Sound level decreases by approximately 6 dB
In a free field, doubling the distance from a point source results in a 6 dB reduction in sound pressure level per the inverse square law.
What does the term criterion level mean in noise dosimetry?
Answer: The constant noise level that produces a 100% dose over the measurement duration
The criterion level is the steady noise level that, if maintained for 8 hours, results in a 100% dose. For OSHA, this is 90 dBA.