Sound Intensity Level
Sound intensity or acoustic intensity is defined as the sound power per unit area. Sound intensity is not the same physical quantity as sound pressure. Hearing is directly sensitive to sound pressure which is related to sound intensity.
Sound intensity level or acoustic intensity level is a logarithmic measure of the sound intensity in comparison to the reference level.
(The decibel (dB) is a logarithmic unit used to express the ratio between two values of a physical quantity, often power or intensity. When referring to measurements of power or intensity, a ratio can be expressed in decibels by evaluating ten times the base-10 logarithm of the ratio of the measured quantity to the reference level.)
|IL||Sound Intensity Level (in dB) (dimensionless)|
|I||Sound Intensity (W*m-2)|
|I0||Reference Intensity (W*m-2)|