Decibel: A decibel is a unit of measurement used to express the ratio of one value of a physical property to another on a logarithmic scale. It is most commonly used to express the relative loudness of sounds, but it can also be used to express other types of physical quantities, such as power levels, voltage levels, and field strengths. The decibel scale is logarithmic, meaning that an increase of 10 dB represents a tenfold increase in the level of the quantity being measured, while an increase of 20 dB represents a hundredfold increase.
Overload: In general usage, "overload" refers to the state of too much or too heavy of a load being applied on an object or system which can cause it to malfunction or fail.
Decibel Overload: It is used to express the relative loudness of a sound intended for music commonly heard from rock and metal music. When you are overloaded with such music, you may reach musical enlightenment as opposed to old beliefs of malfunction or failure.