WIN News: (Aircraft) Noise Levels – and a simple explanation of "noise" in decibels

WIN News: (Aircraft) Noise Levels – and a simple explanation of "noise" in decibels

On Wednesday 22nd July 2009, WIN News ran a story about noise level readings from the the Aircraft Noise Monitor installed in Hackett by AirServices Australia.


Curfew4Canberra issued the following media release in response to the story that was filmed on Tuesday 21 July, 2009:

Media release – 21 July 2009
Community angered by airport’s response – lawnmowers indeed!

Canberra Airport has insulted the intelligence of residents of North Canberra with their analysis of the first results from the Hackett Noise Monitor, says community group Curfew4Canberra.

‘The aircraft noise in North Canberra that Airservices Australia has measured cannot be dismissed as birds and lawnmowers,’ said Jenni Savigny, the group’s President. ‘They have seriously under-estimated the high levels of noise literacy in this community. People also know what their ears tell them.’

‘The Airport’s response shows how desperate they are to talk down aircraft noise in North Canberra, because its existence strikes right at the viability of the proposed 24-hour freight and passenger hub’, said Ms Savigny.

‘The Chief Minister appointed an independent noise expert to settle this question once and for all – where is it?’ asked Ms Savigny. ‘The Federal Minister is due to make a decision on the 24-hour freight hub before 28 August. Without the report from the ACT’s independent noise expert, he won’t have the correct information in front of him.’

‘This report shows exactly why we need an aviation curfew at Canberra Airport, to protect our sleep, just the same as Sydney residents have their sleep protected from 11pm to 6am’ said Ms Savigny.

“‘What scares us is that this report only shows us the aircraft noise in north Canberra at the moment. Imagine how much worse it will be with jumbo jet freighters flying in at night.’

The University of NSW has a web page that gives an excellent and detailed explanation of “dB: what is a decibel”, complete with working examples of sound files at various dB levels to illustrate the relative size (loudness) of a decibel unit.

The page can be accessed here:

The following are approximate descriptions of levels of sound:

  • 0 dB Threshold of hearing
  • 10 dB Rustling of leaves
  • 20 dB Whisper
  • 30 dB Quiet conversation
  • 40 dB Average home
  • 50 dB Normal conversation
  • 60 dB Busy shop
  • 70 dB City street
  • 80 dB Busy workplace
  • 90 dB Underground railway
  • 100 dB Pneumatic drill 10ft away
  • 110 dB Propeller aircraft taking off
  • 120 dB Jet aircraft taking off

It is crucially important to remember that the decibel (dB) is a logarithmic unit, meaning that you cannot add and subtract dB like ordinary numbers. For example, an increase of 3 dB is a doubling of the “strength” of the sound, and an increase of 10 dB means that the sound is 10 times as loud; i.e., 70 dB is 10 times as loud as 60 dB.

Note: copyright of the material in the video clip resides with WIN Television. Usage permitted in accordance with the Australian Copyright Act 1968, Section 42: Fair dealing for purpose of reporting news. Source: WIN News (Canbverra) – 22 July 2009

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