Noise – points of reference in decibels (dBAs)

10Normal breathing
40Quiet residential area or a semi-rural location
42* Airplane Transitions above 20,000 feet.
45-60* Airplane Arrivals between 7,000 and 14,000 feet.
60Normal conversation
60-70* Airplane Arrivals below 7,000 feet.
70Road & Street traffic
85Heavy traffic
90Heavy lorries
110Car horn
140* Airplane taking off
* Typically the sound from an Aircraft is audible for a period of 40-50 seconds.

A difference of 10 decibels is a doubling of loudness.
A difference of 3 decibels is a doubling of sound Intensity.
Baseline – World Health Organisation of 45 dB.