The decibel (abbreviated dB) is the unit used to measure the intensity of a sound. The decibel scale is a little odd because the human ear is incredibly sensitive. Your ears can hear everything from your fingertip brushing lightly over your skin to a loud jet engine. In terms of power, the sound of the jet engine is about 1,000,000,000,000 times more powerful than the smallest audible sound. That's a big difference!
Humans can hear sounds between 0 and 140 decibels. 0 decibel does not mean that there is no sound, merely that we cannot hear it. 0 decibel is the so-called hearing threshold for the human ear. While we can hear more than 140 decibels, it is too painful for our ears and if you expose yourself to such a loud noise you are at extremely high risk of permanent damage to your hearing. The table below shows how loud sound is.
Decibel meter
According to United Kingdom legislation you are obliged to wear hearing protection if you work in an environment with 80 decibels of sound or higher on a daily basis. For fun, check out the following decibel meter.
Example of decibels
DECIBEL |
SOUND |
EXAMPLE |
10 |
Almost inaudible |
A leaf falling |
20 |
Audible |
Rustles of autumnal leaves |
30 |
Very quiet |
Whispering |
40 |
Quiet |
Living room, quiet classroom |
50 |
Limited sound |
Refrigerator working, car driving past |
55 |
Limited sound |
Percolating coffee-maker |
60 |
Audible |
Sound of human voice, machinery |
70 |
Irritating |
Television set on loud, vacuum cleaner, several people on the telephone |
75 |
Constant sound |
Busy restaurant around lunchtime |
80 |
Unpleasant |
Alarm clock, freight traffic, doorbell |
85 |
Loud |
Sawing, mixer |
90 |
Extremely unpleasant |
Truck close by, screaming, yelling, shouting |
95 |
Noisy |
Drill, violin |
100 |
Extremely unpleasant |
Machine in a factory, compressor, fighter jet at 300 m |
105 |
Even louder |
Helicopter close by, large drum |
110 |
Extremely loud |
Rock concert, chainsaw |
120 |
Extremely loud |
Human voice at its loudest, police siren |
130 |
Extremely loud |
Thunder |
140 |
Pain threshold |
First Monday of the month siren from close by |
150 |
Permanent damage to hearing |
Fireworks |
160 |
Permanent damage to hearing |
Shooting with pistol or rifle |
170 |
Permanent damage to hearing |
Avalanche firework |
180 |
Permanent damage to hearing |
Rocket launch platform |
194 |
Permanent damage to hearing |
Saturn rocket |