# Sound energy density

Not to be confused with Sound pressure.

Sound measurements | |
---|---|

Characteristic |
Symbols |

Sound pressure |
p, SPL |

Particle velocity |
v, SVL |

Particle displacement |
δ |

Sound intensity |
I, SIL |

Sound power |
P, SWL |

Sound energy |
W |

Sound energy density |
w |

Sound exposure |
E, SEL |

Acoustic impedance |
Z |

Speed of sound |
c |

Audio frequency | AF |

Transmission loss | TL |

| |

**Sound energy density** or **sound density** is the sound energy per unit volume. The SI unit of sound energy density is the pascal (Pa), that is the joule per cubic metre (J/m^{3}) in SI based units.

## Mathematical definition

Sound energy density, denoted *w*, is defined by

where

*p*is the sound pressure;*v*is the particle velocity in the direction of propagation;*c*is the speed of sound.

The terms instantaneous energy density, maximum energy density, and peak energy density have meanings analogous to the related terms used for sound pressure. In speaking of average energy density, it is necessary to distinguish between the space average (at a given instant) and the time average (at a given point).

## See also

## External links

- Conversion: sound intensity to sound intensity level
- Ohm's law as acoustic equivalent - calculations
- Relationships of acoustic quantities associated with a plane progressive acoustic sound wave - pdf

This article is issued from Wikipedia - version of the 11/3/2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.