A friend claims that, "The sound level of a drill is 90 dB and it doesn't bother me. A rocket launch has a sound level of 180 dB and is considered very dangerous. How can this be, when it is only twice as loud?" Discuss the validity of your friend's statement.
The matter is that with an increase of the sound pressure level by 10 dB sound volume will increase by 2 times. So, sound pressure change by 180db - 90 db = 90 db corresponds in 2*90/10 = 18 times volume increase.