Noise Pollution Chapter 16. What’s the difference between a sound and a noise? (Intro & Section 16.3). Pressure Waves (Section 16.1). Source. Sound Pressure Level. SPL = 10 log (P 2 /P o 2 ) P o = 0.00002 Pa Units: dB. Typical SPLs.
SPL = 10 log (P2/Po2)
Po = 0.00002 Pa
Measurements by Gordon Hempton, “an acoustic ecologist and sound recordist”
For n sources of the same dB:
SPLTotal = 10 log n + SPLo
Your company is purchasing an additional piece of manufacturing equipment. You have two choices. One brand generates 91 dB(A); another brand costs 10% more but generates 88 dB(A). You determine that the current level of noise in the production area is 88 dB(A). The workers are on 8-hour shifts. The OSHA 8-hour noise limit for the area is 93 dB(A). The company has been doing well and has thoughts of expanding production at this location in the near future. Determine which piece of equipment to purchase.
SPL average from a frequency analysis
N = number of measurements taken
TimeOther Issues(Section 16.2)
Time Varying SPL
Who regulates noise levels?
What are some options for abating or controlling traffic noise?