▶ BASICS OF SOUND INSULATION: UNDERSTANDING NOISE
How can noise levels be measured?
The unit used in acoustics to define and measure sound intensity is Decibel (dB). Decibel uses a logarithmic scale which works very differently from a linear scale.
Why is noise measured with a logarithmic scale?
Sound | Decibel level |
Breathing | 10 dB |
Rustling leaves | 20 dB |
Whisper | 30 dB |
Quiet conversation | 40 dB |
Light trafic at close range | 50 dB |
Normal conversation | 60 dB |
Vacuum cleaner | 70 dB |
Loud traffic noise at close range | 80 dB |
Headphones at full volume | 90 dB |
Club | 100 dB |
Car speakers at full volume | 110 dB |
Air plane take-off, jackhammer | 120 dB |
Rock concert | 130 dB |
What is the increase in sound intensity between two different Decibel levels ?
Sound intensity is the energy needed to produce a given level of sound and not to be confused with sound volume which is the level at which we perceive the resulting sound.
The mathematical relationship between Decibel (dB) and sound intensity works as follows: each 10 dB increase results in a 10-fold increase in sound intensity which we perceive as a 2-fold increase in sound volume. Thus, from 0 dB to 10 dB there is a 10-fold increase in sound intensity, just as there is from 10 dB to 20 dB or from 34 dB to 44 dB.
Decibel levels for everyday noises VS. increase in sound intensity and perceived volume:
Sound | Decibel level | Increase in sound intensity | Increase in perceived volume |
0 dB | |||
Breathing | 10 dB | 10 times the sound intensity | 2 times as loud |
Rustling leaves | 20 dB | 100 times the sound intensity | 4 times as loud |
Whisper | 30 dB | 1,000 times the sound intensity | 8 times as loud |
Quiet conversation | 40 dB | 10,000 times the sound intensity | 16 times as loud |
Light trafic at close range | 50 dB | 100,000 times the sound intensity | 32 times as loud |
Normal conversation | 60 dB | 1,000,000 times the sound intensity | 64 times as loud |
Vacuum cleaner | 70 dB | 10,000,000 times the sound intensity | 128 times as loud |
Loud traffic noise at close range | 80 dB | 100,000,000 times the sound intensity | 256 times as loud |
Headphones at full volume | 90 dB | 1,000,000,000 times the sound intensity | 512 times as loud |
Club | 100 dB | 10,000,000,000 times the sound intensity | 1024 times as loud |
Car speakers at full volume | 110 dB | 100,000,000,000 times the sound intensity | 2048 times as loud |
Air plane take-off, jackhammer | 120 dB | 1,000,000,000,000 times the sound intensity | 4096 times as loud |
Rock concert | 130 dB | 10,000,000,000,000 times the sound intensity | 8192 times as loud |