A decibel or dB measures power or intensity. Most often, it is used to say how loud a sound is relative to the threshold of hearing. At the moment, the decibel is not an SI unit. dB are units of sound mostly for consensus on hearing protection.
[change] Examples and protection
Some examples of sounds are:
|200-250 dB||Cannon at 12 feet|
|175-200 dB||Saturn Rocket firing|
|150 dB||Airplane at takeoff|
|130 dB||Above this can damage the ear quickly, and pain is felt.|
|120 dB||Diesel engine, ball mill|
|100 dB||Lawn mower, factory|
|90 dB||Band or symphony, above this can damage the ear if heard extensively.|
|80 dB||Police or fire siren, electric shaver|
|70 dB||Radio sound level, crowded neighborhood.|
|50 dB||Can normally awaken a sleeping person.|
|30-35 dB||Very quiet conversation, private office noise|
|20 dB||Rustling leaves, whispering|
|10 dB||Sound-proofed room, the minimum most human ears can hear|
|0 dB||Hearing threshold.|
Hearing protection can also be used to shield from ear damage.
|Decibels||Maximum Exposure Time|
- Pocket Ref, General Sciences, pages 322-323.