Science & Technology in Action

8th Edition

Protecting us from noise


This lesson outlines the adverse effects and cost of noise. The EU Directive on Environmental Noise (Directive 2002/49/EC) set out a common approach across the EU to reduce the harmful effects of environmental noise.
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Lesson excerpt

An EU approach to noise measurement
The Directive on Environmental Noise (Directive 2002/49/EC) set out a common approach across the EU to reduce the harmful effects of environmental noise. It also outlined a common approach to the measurement and control of environmental noise. The ‘noise’ in question results from human activities such as transport and industry. It does not deal with noise from neighbours, noise in the workplace, noise within vehicles or indeed the barking of dogs at night.

Putting a price on noise
Noise is unwanted sound. Loud continuous noise makes conversation difficult; it causes annoyance and can adversely affect a person’s health. More than 30% of the European population experience noise levels that disrupt sleep or speech, and 20% are regularly exposed to noise levels that scientists consider an unacceptable health risk. However, Ireland has a relatively low level of complaints about noise disturbance compared to other countries in the EU, where most sleep disturbance and annoyance are associated with road traffic noise, and to a lesser extent with rail and airport activity. While it can be difficult to put a price on the social cost of noise, one report
(den Boer & Schroten. 2007. Traffic noise reduction in Europe. p. 21) estimates the yearly social cost of noise in Europe at €38 billion.

Our ears detect rapid air pressure variations. If the variations are regular we perceive the sound as a note. In general we can hear notes in the range 16 hertz to 16,000 hertz (i.e. 16 kHz). One hertz (1 Hz) means one (vibration) per second. Low frequency ‘sounds’ (below 16 Hz) may not be directly audible but may cause windows or indeed buildings to vibrate. If the sound is loud enough and matches the resonant frequency of a building it can even cause structural damage.

True or False?

  1. Sound and noise are the same thing. false
  2. In Europe the annual social cost of noise is about €100 million. false
  3. Our ears typically detect sound in the range 16 Hz to 16 kHz. true
  4. Zero on the decibel scale indicates absolute silence. false
  5. Many animals can hear sounds that humans cannot hear. true
  6. Increasing the distance from a sound source by a factor of 10 changes the sound intensity by a factor of 1/100. true
  7. A decibel is a tenth of a bel. true
  8. The dB(A) scale gives a better representation of perceived sound levels. true
  9. Sound cannot go around corners. false
  10. The sound of distant traffic has enhanced high frequencies. false
  11. Environmental noise decreases the quality of people’s lives. true