Noise pollution

Question 1

Effects of noise pollution on living organisms
HUMANS

Answer 1

-headache
-burst eardrum
-permanent damage
-hearing loss
-increased stress levels
-heart problems (increased blood pressure)
-behavioural changes (easy anger)
-communication problems

Question 2

Effects of noise pollution on living organisms
OTHER

Answer 2

-unable to call for young/hear young
-disturbance to livestock (panic, injury, failure to breed)
-disturbance of breeding birds
-sudden noises to leave nets/eggs
-reduce feeding success
-struggle to hear pray
-citations, whales and dolphins susceptible to sonar (military) linked to mass beaches

Question 3

effects of noise pollution on non living organism

Answer 3

-vibrations
-shatter (glass)
-sonic boom (travelling faster than speed of sound)
-acoustic fatigue (stress cracks)

Question 4

Measuring noise
The decibel scale

Answer 4

loudness of a sound

Question 5

Measuring sound
The dB (A) scale

Answer 5

-decibel sound adjusted for human hearing
-o level is the lowest level we think humans can hear

Question 6

Measuring sound
LA10

Answer 6

-measures noise levels at its worst
-nosiest (10%)

Question 7

Measuring sound
LA90
(road traffic)

Answer 7

-measures the noise levels in the quietest end of the scale

Question 8

Measuring sound
L1018h (traffic noise)
(road traffic)

Answer 8

same as LA10 but in an 18hr period

Question 9

Measuring sound
Traffic noise index (TNI)
(road traffic)

Answer 9

-a full picture of what people are being subjected too

Question 10

Measuring sound
effective perceived noise levels EPNL
(aircraft)

Answer 10

-estimate of noise during take off, flying and landing
-a relative scale (interested in whether if it’s noisier in comparison to noise levels)

Question 11

Measuring sound
Noise and number index NNI
(aircraft)

Answer 11

-combines number of flights and noise levels of aircraft above 80 decibels
-below 80 doesn’t count as annoyance

Question 12

Measuring sound
Leq 57dB
(aircraft)

Answer 12

-average sound level over a particular period.
-UK airports have an average of 57dB
-between 7am-11am is used

Question 13

Sources of aircraft noise

Answer 13

-engine noise
-turbines
-landing, take off, breaking
-air moving over wings
-air being drawn into engine and expelled
-drag, friction (resistance)

Question 14

Reduction of aircraft noise through Airpot design

Answer 14

-building airports always from domestic property’s
-have run way away from domestic properties
-taxing areas away from residential properties
-airplane test centres (safety checks/MOTs) away from domestic properties
-multiple landing runways (less reverse thrusting/quieter landing)
-upgrading windows (mitigating)
-surround airports with barriers to absorb noise (vegetation)
-restriction areas around airport, so not used for domestic props

Question 15

Reduction of noise through engine/aircraft design

Answer 15

-chevron nossles encourage batter mixing of air decreasing noise levels
-improvement of aerodynamics reduction of drag and resistance
-covered fairings anything that protrudes and smoothing them to make them more aerodynamic
-blended wing aeroplanes only used for smaller military aircraft’s
-light weighting of aircraft use of aluminium or carbon fibre, for things that don’t require high strength
-high bypass ratio engine
has air moving around engine that mixes with air exiting the engine before released, so air release is moving at a similar speed to outmoded air creating less noise
-acoustic liners have material around the engine that absorb noise
-engine hush kits work like chevron nossles , work with high bypass ratio

Question 16

reduction of noise by airport operation

Answer 16

-time restrictions on take off and landing
-restricting or banny of nosier aircraft’s
-regularly changing flight paths (incoming and outgoing) people less subjected too noise
-steep angle of ascent, taking off as steep as possible (noise however, much higher up in sky and quicker)
-shallow landing at a constant land of decent (when coming down not using engine a lot less nosier)
-quota count system- airports given total number of points, each aircraft have winter flights as don’t want to use up points. Can have many quiet planes or few noisy planes
-night time flight restrictions

Question 17

Other noise sources
Railway sources and control/ reduction measure

Answer 17

1.wheel vibrations-polishing the track, use of gravel as sound absorbing ballast
2.engine noise-sound absorbing suspension
3.pantograph turbulence-aerodynamic faring
4.wheel squeal on corners- lubricator of wheels/track
5.barking squeal-use or composite material brakes
6.wheel noise-good carriage suspension