You hear the term, dB. Decibel. But do you really know what it means? Here is a GREAT post about what it is.
The first thing to understand is that zero decibels does not mean silence. Instead, it refers to the quietest sound that humans can hear, which is roughly equivalent to the sound of a mosquito from ten feet away. All other decibel levels are multiples of this reference intensity.
ethanhein.com