For example, the intensity of a jet

For example, the intensity of a jet plane just.leaving the runway, which is about 100 W/m2, has an intensity level
o_in, 100 W/m2
/3 10 log 10 log 1Q x 1Q_12 w/m2
= 10 log 1014 = 10(14) = 140 dB
Every increase in intensity by a factor of 10 therefore corresponds to an increase of 10 dB. Hence a sound of 100 W/m2 is 140 dB, or 1014 times as intense, as the threshold of hearing.