Question

1. Sound and vibration are very similar. Which of the following statements are true? A. Sound relates to a sensation B. Vibration is inaudible C. Vibration is perceived through the sense of touch D. All of the above

2. What level of DBA is considered the maximum limit of continuous exposure over eight hour days without protection? A. 150 B. 3 C. 90 D. 20

3. Identifying and assessing hazardous noise conditions in the workplace involve which of the following? A. Conducting periodic noise surveys B. Conducting periodic audiometric tests C. Record keeping and follow up action D. All of the above

4. Noise is distinguished from sound by which of the following factors? A. Intensity of noise B. Unwanted sound C. Type of noise D. Duration of exposure

5. Noise control strategies include which of the following? A. Noise can be reduced at the receiver by enclosing the worker B. Noise can be reduced along its path by moving the source farther away C. Noise can be reduced at its source by enclosing the source D. All of the above

6. Which of the following is the name given to reduction of sound transmission using materials and/or structural elements? A. Active noise reduction B. Parallel noise reduction C. Structural noise reduction D. Passive noise reduction

7. Trying out HPDs to determine how they fit with an individual’s anatomical features is known as what? A. Trial PPE run B. Fit testing C. PPE testing D. PPE run through

8. Which of the following is NOT a strategy for limiting employee exposure to vibration hazards? A. Work rotation B. Tool mounting C. Insulation on tool handles D. Reinforcing employee work habits

9. A major safety concern relating to the use of hand-held electronic devices by employees in the workplace is what? A. Playing games when they should be working B. Streaming videos when they should be working C. Distraction from the tasks at hand D. Becoming tangled in cords

Answer 1

1. (D) All of the above

Vibration is inaudible and is perceived through the sense of touch.

2. (C) 90 DBA

Occupational Safety and Health Administration(OSHA) has set legal limits on noise exposure in the workplace. These limits are based on a worker's time-weighted average over an 8 hour day. With noise, OSHA's permissible exposure limit (PEL) is 90 dBA for all workers for an 8 hour day.

3. (D) All of the Above

The steps to perform a Noise Risk Assessment are, Identify, Evaluate, Implement Control Measures and Monitor. All the steps include periodic surveys of the workplace.

4. (B) Unwanted Sound

Noise is unwanted sound. The difference between sound and noise depends upon the listener and the circumstances. Rock music can be a pleasurable sound to one person and an annoying noise to another.

5. (D) All of the Above

Noise Control Strategies

• Using "silenced" or muffled equipment.
• Maintaining equipment and keeping tools sharp.
• Locating noisy equipment as far as feasible from work areas.
• Not locating noisy equipment near hard reflecting or reverberating surfaces.
• Erecting barriers between the noise source and workers.

6. (C) Structural Noise Reduction

Noise can be reduced by eliminating windows and other openings from the walls of a building close to noise sources. The solid wall(Structure) can then have the effect of a sound barrier for the rest of the building.

7. (B) Fit Testing

8. (B) Insulation of Tool Handles

The use of resilient material between the source and the worker's hand reduces the vibration levels at the hand. However, a resilient hand-grip compressed by the worker's hand will have natural frequencies that are likely to higher.

9. (C) Distraction from the Task at Hand

Handheld electronic devices do not have cords. The safety concerns at the workplace where heavy machinery is being used dictates that the workers should always be attentive to what is happening around. Electronic devices, like cellphones cause distraction which is a major safety risk.