Sound energy density


Sound energy density or sound density is the sound energy per unit volume. The SI unit of sound energy density is the pascal (Pa), which is 1 kg⋅m−1⋅s−2 in SI base units or 1 joule per cubic metre (J/m3).[1]: Section 2.3.4: Derived units, Table 4 

Sound measurements
 Sound pressure p, SPL, LPA
 Particle velocity v, SVL
 Particle displacement δ
 Sound intensity I, SIL
 Sound power P, SWL, LWA
 Sound energy W
 Sound energy density w
 Sound exposure E, SEL
 Acoustic impedance Z
 Audio frequency AF
 Transmission loss TL

Mathematical definition edit

Sound energy density, denoted w, is defined by



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).

Sound energy density level edit

The sound energy density level gives the ratio of a sound incidence as a sound energy value in comparison to the reference level of 1 pPa (= 10−12 pascals).[2] It is a logarithmic measure of the ratio of two sound energy densities. The unit of the sound energy density level is the decibel (dB), a non-SI unit accepted for use with the SI Units.[1]: Chapter 4: Non-SI units that are accepted for use with the SI, Table 8 

The sound energy density level, L(E), for a given sound energy density, E1, in pascals, is


where E0 is the standard reference sound energy density[3]


See also edit

References edit

  1. ^ a b Newell, David B; Tiesinga, Eite, eds. (2019). The international system of units (SI) (PDF) (Report). Gaithersburg, MD: National Institute of Standards and Technology. doi:10.6028/nist.sp.330-2019.
  2. ^ Deutsches Institut für Normung, Grundlagen der Schallmessung; Physikalische & subjektive Größen von Schall, Physical & subjective magnitudes of sound, Norm, Standard, № DIN 45630‑1:1971‑12 (Berlin: Beuth, 1971‑12).
  3. ^ Deutsches Institut für Normung, Akustik—Begriffe, Acoustics—Terminology, Norm, Standard, № DIN 1320:2009-12 (Berlin: Beuth, 2009‑12).

External links edit

  • 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