Sound energy density is the time-averaged sound energy in a given volume divided by that volume. The sound energy density or sound density (symbol $E$ or $w$) is an adequate measure to describe the sound field at a given point as a sound energy value.
$E = \frac{I}{c}$, where $I$ is the sound intensity in $\frac{W}{m^2}$ and $c$ is the sound speed in $\frac{m}{s}$.
Applicable units are those of quantitykind:EnergyDensity
Sound Energy Density