# noise measurements

noise measurements.

I need help with a Management question. All explanations and answers will be used to help me learn.

1-Several different units can be used for sound pressure. Please list at least 4 different units.

2-Can you use sound level meter to distinguish between a sound and a noise? Why?

3-If two machines are located in a room, machine A can produce 89.8 dB while machine B can generate 92.5 dB. What is the combined sound level if both machines are in operation? Please use two different methods to determine the combined sound level: 1) use the Simplified Table but need to explain step by step how you get the result. 2) use an equation listed by ABIH.

4-What is the period of a sound?

5-Why Root-mean-square is important for sound level calculation?

6-You work as an EHS manager at ABC company with four machines in a room. The four machine can produce 75, 79, 81, and 83 dB, respectively. 1) Please explain if company needs to implement a Hearing Conservation program when all 4 machines are in operation. 2) Your boss asked you to determine if it is possible to relocate one of four machines, so that workers canâ t be exposed to more than 85 dB and the company will save on Hearing Conservation program. The boss also required to have the highest productivity after the rearrangement (unfortunately, the louder machine has the higher productivity). Please determine which machine you can relocate. Show your calculations to your boss!

7-If the lower limit of human hearing is 20 Hz and the speed of sound in air is 1100 ft/sec, what is the wavelength of the sound wave at a frequency of 20 Hz?

8-What is the range of sound frequencies that healthy, young person can hear?

9-What is the crest and trough of sound wave?

10-Please use your own words to explain how the length of the pendulum and the mass of bob (the ball on the end of a pendulum) can affect the period of a pendulum.

11-The pain threshold of sound to human is about 140 dB. Please convert 140 dB to sound pressure and expressed with at least 3 different sound pressure units.

12-What’s different between sound pressure and sound pressure level?

noise measurements