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environmental ethics > ch9: Noise pollution > Flashcards

ch9: Noise pollution Flashcards

1
Q

The nature of sound

A
  • Sound, a manifestation of vibration, travels in wave patterns through solids, liquids and gases.
  • The waves, caused by vibration of the molecules, follow sine functions, typified by the amplitude and wavelength (or frequency)
  • Sound waves of equal amplitude with increasing frequency from top to bottom
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2
Q

People generally hear sounds between

A

the “threshold of hearing” and the “threshold of pain”

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3
Q

People generally hear sounds between the “threshold of hearing” and the “threshold of pain” In terms of pressure, this is

A

20 upa - 100 pa

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4
Q

People generally hear sounds between the “threshold of hearing” and the “threshold of pain” In terms of pressure, this is 20 μPa – 100 Pa

…………………………. was developed from this fact and ……………………………..

A

the decibel scale

makes numbers more manageable

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5
Q

The decibel scale generally ranges from

A

approximately 0 to 130

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6
Q

the sound pressure of the faintest sound that a normal healthy individul can hear is about

A

0.00002 pa

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7
Q

the sound pressure produced by a saturn rocket at liftoff is

A

greater than 200 pa

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8
Q

the sound pressure produced by a saturn rocket at liftoff is greater then 200 pa. even in scientific notation this is

A

an astronomical range of numbers

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9
Q

the sound pressure produced by a saturn rocket at liftoff is greater then 200 pa. even in scientific notation this is an astronomical range of numbers. to cope with this problem

A

a scale based on the logarithm of the ratios of the measured quantities is used.

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10
Q

the sound pressure produced by a saturn rocket at liftoff is greater then 200 pa. even in scientific notation this is an astronomical range of numbers. to cope with this problem a scale based on the logarithm of the ratios of the measured quantities is used.

measurements on this scale are called

A

levels

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11
Q

the sound pressure produced by a saturn rocket at liftoff is greater then 200 pa. even in scientific notation this is an astronomical range of numbers. to cope with this problem a scale based on the logarithm of the ratios of the measured quantities is used. measurements on this scale are called levels.

the unit for these types of measurement scales is

A

the bel

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12
Q

level, bels:

A

L=log( Q/Q0)

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13
Q

L=log( Q/Q0​) explain the terms

A

L = levels, bels

Q= measured quantity

Q0= reference quantity

log= logarithm in base 10

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14
Q

bel turns out to be

A

larger unit so for convenience it is divided into 10 subunits called decibels (dB)

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15
Q

levels in decibels are computed as follows

A

L=10log Q/Q0

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16
Q

the decible doesnt represent

A

any physical unit. it indicates that a logarithmic transformation has been performed

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17
Q

W: Sound energy

A

is a form of energy associated with the vibration of matter.

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18
Q

I: Sound intensity

A

also known as acoustic intensity is defined as the Energy carried by the sound waves per unit area

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19
Q

If the reference quantity Q0 is specified then

A

the decibel takes physical significance

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20
Q

for noise measurements the reference power level has been established as

A

10-12 W

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21
Q

sound power level may be expressed as

A

Lw = 10 log (w/10-12)

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22
Q

for noise measurements, the reference sound intensity is

A

10-12 W/m2

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23
Q

sound intensity level

A

Li = 10 log (I/10-12)

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24
Q

sound measuring instruments measure

A

Prms

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25
Q

sound pressure level =

A
26
Q

the reference pressure has been established as

A

20 uPa (micropascal)

27
Q

Humans are less sensitive to

A

low frequency sound

28
Q

humans are more sensitive to

A

high frequency sound

29
Q

Humans are less sensitive to low frequency sound and more sensitive to high frequency sound. Therefore,

A

sometimes the dB scale is adjusted to take this into account

30
Q

sometimes the dB scale is adjusted to take this into account:

A
  • A-weighting (db(A)): adjusts overall scale so it better matches what the human ear would hear
  • C-weighting (dB(C)): adjusts scale for loud or low frequency sounds
  • B-weighting (dB(B)): adjusts by factors that are “in between” the A-weighted factors and C-weighted factors (rarely used)
31
Q

human hearing and frequency graph

A
32
Q

how sound is measured

pressure

A

P

usually in pascals

p=1/f

33
Q

how sound is measured

frequency

A

f

usually in hertz

34
Q

how sound is measured

intensity

A

I

usually W/m2

I=W/A

35
Q

How sound is measured

bels

A

L’

derived from logarithmic ratio

L’=log (Q/Q0)

36
Q

How sound is measured

Decibels

A

L

derived from bels

L=10*log (Q/Q0)

37
Q

Implications of the decibel scale:

A

doubling sound level would mean that the sound will increase by 10*log2 = +3dB Ten times the sound level = 10*log10 = +10dB

38
Q

Other descriptors of sound

A
  • Equivalent sound level – the level of sound that has the same acoustical energy as does a time-varying sound over a stated time period.
  • Percentile sound level – the sound level exceeded “n” percent of the observation time interval.
  • Day-night average sound level – the equivalent sound level for a 24-h period that incorporates a decibel penalty during night hours.
39
Q

Noise” derived from

A

“nausea,” meaning seasickness

40
Q

Noise is among the most

A

pervasive pollutants today

41
Q

Noise is unavoidable for

A

many machines

42
Q

We experience noise in a number of ways

A
  • üenvironmental
  • ücause and victim
  • generated by others “second-hand”
43
Q

Noise negatively affects

A

human health and well-being

44
Q

The air into which second-hand noise is

A

emitted and on which it travels is a “commons“, a public good

45
Q

NOISE POLLUTION

A

¢Sound that is unwanted or disrupts one’s quality of life is called as noise. When there is lots of noise in the environment, it is termed as noise pollution.

46
Q

Sound becomes undesirable when it

A

¢disturbs the normal activities such as working, sleeping, and during conversations.

47
Q

Sound becomes undesirable when it disturbs the normal activities such as working, sleeping, and during conversations.

It is an underrated environmental problem because

A

of the fact that we can’t see, smell, or taste it.

48
Q

World Health Organization stated that (about noise pollution)

A

Noise must be recognized as a major threat to human well-being

49
Q

Noise must be recognized as a major threat to human well-being

A

direct links between noise and health. Also, noise pollution adversely affects the lives of millions of people

50
Q

Noise pollution can damage

A

physiological and psychological health.

51
Q

the health problems related to noise pollution

A
  • High blood pressure,
  • stress related illness,
  • sleep disruption,
  • hearing loss, and
  • productivity loss
  • memory loss
  • severe depression
  • panic attacks
52
Q

Sources of Noise Pollution

A
  • •Transportation systems are the main source of noise pollution in urban areas.
  • •Construction of buildings, highways, and streets cause a lot of noise, due to the usage of air compressors, bulldozers, loaders, dump trucks, and pavement breakers.
  • •Industrial noise also adds to the already unfavorable state of noise pollution.
  • •Loud speakers, plumbing, boilers, generators, air conditioners, fans, and vacuum cleaners add to the existing noise pollution.
53
Q

Noise contours around an airport calculated using

A

INM (Integrated Noise Modeling)

54
Q

Noise contours around an airport calculated using INM (Integrated Noise Modeling) based on

A

previous noise measurements

55
Q

Other sources of noise pollution that need to be addressed

A
  • Boat noise, especially jet skis
  • Construction noise
  • Snow mobiles
  • Industry
56
Q

Solutions for Noise Pollution

A
  • Planting bushes and trees in and around sound generating sources is an effective solution for noise pollution.
  • Regular servicing and tuning of automobiles can effectively reduce the noise pollution.
  • Buildings can be designed with suitable noise absorbing material for the walls, windows, and ceilings.
  • Workers should be provided with equipments such as ear plugs and earmuffs for hearing protection.
  • Similar to automobiles, lubrication of the machinery and servicing should be done to minimize noise generation.
  • Soundproof doors and windows can be installed to block unwanted noise from outside.
  • Regulations should be imposed to restrict the usage of play loudspeakers in crowded areas and public places.
  • Factories and industries should be located far from the residential areas.
  • Community development or urban management should be done with long-term planning, along with an aim to reduce noise pollution.
  • Social awareness programs should be taken up to educate the public about the causes and effects of noise pollution.
57
Q

Roadway Noise

A

An example of a “line source” of noise pollution (as opposed to a “point source”)

58
Q

Level of noise is a function of

A
  • volume,
  • type of vehicle, and
  • speed
59
Q

Roadway Noise - Solutions

A
  • • Regulations limit the amount of noise some vehicles can produce
  • • Some regulations require vehicles to be properly operated and maintained
  • • Despite regulations, the noise levels are usually only reduced by 5 to 10 dBA

Barriers

  • •Buffer zones
  • •Earth berms/wooden fences/concrete walls
  • •Vegetation (if dense enough)

Pavement type

  • Certain asphalts, such as those containing rubber or stone, can be less noisy than other pavements.
  • However, some studies have shown the reduction in noise is only a few decibels, not enough to be significant.
  • More research is needed before pavement type can be an effective noise-reducing technique
60
Q

air noise solutions

A

environmental ethics (14 decks)

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