Noise Pollution - Saraniecki Flashcards
What are regulations as detailed by the Aviation Safety and Noise Abatement Act of 1979?
requires FAA to develop noise maps and a method of measuring airplane noise pollution
What are the Federal Highway limits?
67 dBA near sensitive areas
72 dBA for commercial land use
What are the EPA and DOT noise regs?
90 dBA for interstate trucks and buse at 35mph
86 dBA under 35mph
New truck max is 83 dBA
What are the three terms to describe and measure sound?
amplitude - loudness
frequency - pitch
time pattern
Define noise pollution
noise that has characteristics and duration injurious to public health and welfare or unreasonably interferes with the comfortable enjoyment of life and property
Define decibel
a dimensionless unit used to express intensity of sound
What is a dBA scale?
an attempt to measure the way the human ear hears loudness (amplitude) in normal situations
emphasizes high frequencies
What is the dBC scale?
an attempt to measure the way the human ear hears loudness (amplitude) in noisy situations
What is the dBD scale?
an attempt to measure and compare the effect of airplane noise on the human ear
What is the graph regarding difference between two sounds and how much to add in dB to the higher sound?
0 - 3.0
1 - 2.6
2 - 2.1
3 - 1.8
4 - 1.5
5 - 1.2
6 - 1.0
7 - 0.8
8 - 0.6
10 - 0.4
12 - 0.3
14 - 0.2
16 - 0.1
What should you do for two sounds of the same dB? Three?
two - add 3.0 dB
three - add 4.8 dB
Define sone
measure perceived loudness by an observer
Define phon
loudness level of 1 kHz tone at 40 dB
40 phons = 1 sone
Define sabin
a measure of the sound absorption ability of a surface
Define sound-level meter
measures environmental sound in dBA and should include time
What is a noise dosimeter?
measures amount of potentially injurious noise exposure over time
What is the OSHA 2-3 foot rule?
When a sound level meter is not available
stand an arm’s length from your coworker
if you have to raise your voice to be heard 2-3 ft away, assume sound level is at or above 85 dB and should be investigated
Where can noise be controlled at?
source
transmission path
where received
2 or 3 controls typically used simultaneously
How are noise levels affected by distance from source?
drops 6 dB each time the distance from source to received is doubled
What is the noise threshold of pain?
120 dBA
Give examples of source control
aka Engineering controls
proper planning and design
isolate the noisy industrial process
substitute less noisy processes
replace noisy equipment with modern quiet equipment
vibration isolators
proper maintenance - mufflers, worn parts
Describe transmission path control
Hard, smooth, impervious materials reflect sound - rubber
absorptive materials - rugs, carpets, drapes, acoustical walls and ceiling tiles, more effective for high frequency sounds
What is sound transmission loss? Some example requirements?
the ratio of the energy passing through a wall, floor, or ceiling to the energy striking it
walls between apartments should have sound reduction wall of at least 50 dBA
expressway noise barrier walls
What happens to transmission loss when frequency increases?
Transmission loss increases
