Sound energy

In physics, sound energy is a form of energy that can be heard by humans. Sound is a mechanical wave and as such consists physically in oscillatory elastic compression and in oscillatory displacement of a fluid. Therefore, the medium acts as storage for both potential and kinetic energy.[1]

Consequently, the sound energy in a volume of interest is defined as the sum of the potential and kinetic energy densities integrated over that volume:

${\displaystyle W=W_{\mathrm {potential} }+W_{\mathrm {kinetic} }=\int _{V}{\frac {p^{2}}{2\rho _{0}c^{2}}}\,\mathrm {d} V+\int _{V}{\frac {\rho v^{2}}{2}}\,\mathrm {d} V,}$

Here:

• V is the volume of interest;
• p is the sound pressure;
• v is the particle velocity;
• ρ₀ is the density of the medium without sound present;
• ρ is the local density of the medium;
• c is the speed of sound.