Time averaged sound intensity
Sound intensity or acoustic intensity ($I$) is defined as the sound power $P_a$ per unit area $A$. The usual context is the noise measurement of sound intensity in the air at a listener's location as a sound energy quantity.
Applicable units are those of quantitykind:PowerPerArea
http://en.wikipedia.org/wiki/Sound_intensity
Sound intensity or acoustic intensity ($I$) is defined as the sound power $P_a$ per unit area $A$. The usual context is the noise measurement of sound intensity in the air at a listener's location as a sound energy quantity.
$I = \frac{1}{t2 - t1} \int_{t1}^{t2}i(t)dt$, where $t1$ and $t2$ are the starting and ending times for the integral and $i$ is sound intensity.