Noise Pollution Flashcards
Definition of noise pollution
Excessive or harmful levels of noise in the environment which can disrupt normal activities, harm human health and negatively affect wildlife
Effects of noise pollution on humans
Hearing loss
Sleep disturbance
Stress and anxiety
Cardiovascular issues - increases blood pressure - increase risk of heart diseases
Effects of noise pollution on other living organisms
Wildlife disruption - animals rely on sound for navigation
Leads to difficulties in finding mates and food
Change in behaviour
Habitat loss - areas becoming less hospitable
Effects of noise pollution on non-living organisms
Impacts on soil and water
Building and structures damaged
Shock impacts - sonic booms - glass breaking etc
Buildings - acoustic fatigue - materials vibrate and break down
How is LA10 used to measure pollution
Measure of noise levels that represent the sound level exceeded for 10% of a given time period
How is LA90 used to measure noise pollution
Statistical measure of noise levels that indicates the sound levels exceeding for 90% of a given time
How is the decibel scale used to measure noise pollution
Measures sound intensity
Logarithmic
Sources of aircraft noise
Noisiest during takeoff and landing
Air moving over an aircraft - increased friction - more noise
Inflight - less of a nuisance, as it’s far away from built up areas
Reduction of aircraft noise through airport design
Surround airport with absorbent materials - e.g vegetation
Build baffle mounds - raised areas
An engine test centre - test engine to maximum - away from residential areas
Having multiple runways - more time for landing and takeoff
Reduction of noise through engine designs
Increase aerodynamics
Use lighter materials - e.g aluminium
Acoustic lining - outer skin of the engine
Reduction of noise by aircraft operation
Time restrictions - mainly at night
Rotation of flight paths - less nuisance to residential areas
Angle of takeoff - steep - quicker to take off but there is more noise but doesn’t last long
Sources and reduction methods of railway noise
Wheel vibration - track polishing
Engine noise - sound absorbing suspension
Wheel squeal on corners and bends - lubrication of tracks and wheels
Sources and reduction methods of road traffic noises
Wheel noise - sound absorbing road materials
Engine noise - acoustic insulation - just inside the engine
General vehicle noise - fences/vegetation, double glazing for nearby infrastructure
Sources and reduction methods of industrial noise
Air compressor and pumps - silencers
Stamping machines - don’t stamp mold, press instead
Metal conveyor belts - use alternative materials e.g plastic
