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
How can you control noise where it is received?
limit worker exposure time
PPE
this is the last choice for noise control
What are some examples of administrative control in regards to noise?
worker rotation
increase worker distance to noise source
What is the noise limit for mass gathering?
70 dBA
What are OSHA noise limits?
action level - 8 hr avg of 85 dBA - monitoring and worker notification
8 hr TWA PEL - 90 dBA
allowable exposure time is halved when the noise level increases by 5 dB
PPE
EPA - 24 hr exposure of 70 dBA is safe
How is noise hazardous?
Loud sounds affect the circulatory and nervous systems
continuous exposure to high level noise is more harmful than intermittent or occasional exposure
for workers, 85 dBA levels should be investigated
90 dBA are unsafe
What are regulations for garbage compactor trucks?
may not exceed 76 dBA within 23 ft of any side of the truck
What is the maximum sensitivity to sounds for humans?
1000-5000 cps
cps = cycles per second = Hz
What is temporary threshold shift?
hearing loss that lasts a few hours after excessive noise exposure
What is sensorineural loss?
loss of hearing to the extent that low frequency sounds are distorted or can’t be heard
What is conductive loss?
hearing loss that results from infections or trauma
What is presbycusis?
age-related hearing loss
When does a fetus develop hearing ability?
28th week of gestation
Which act authorized the EPA to work with state and local govt for anti noise programs?
Quiet Communities Act
The unit of measurement most commonly used to measure loudness
phon
What is the most common type of noise measurement device used for initial surveys to provide rapid evaluation and identification of potential problem areas?
sound level meter
