Sound energy density
The sound energy density (symbol E or w ) is a measure to describe the sound energy present at a certain location in the sound field . It is a sound energy quantity . The associated logarithmic quantity is the sound energy density level.
The sound energy density E is the sound energy per volume unit:
In the special case of the even advancing wave, the time-averaged sound energy density is:
Sound energy density level
Occasionally the sound energy density is also given in the form of a sound energy density level L E in decibels (dB):
The reference value is defined as J / m³ or W · s / m³.
Relationships in the plane wave
Further formulas for the sound energy density for flat, progressing sound waves:
|E.||W · s / m 3||Sound energy density|
|ξ||m , meter||Sound deflection|
|= 2 · · f||rad / s||Angular frequency|
|ρ||kg / m 3||Air density , density of the air (of the medium)|
|v||m / s||Speed of sound|
|a||m / s 2||Sound acceleration|
|Z = c ρ||N · s / m 3||Characteristic acoustic impedance, acoustic field impedance|
|I.||W / m 2||Sound intensity|
|c||m / s||Speed of sound|
|P ak||W, watt||Sound power|
|A.||m 2||Transmitted surface|
- Sound energy density and the relationship between the acoustic quantities in the case of flat, progressing sound waves (PDF; 109 kB)
- Sound quantities, their levels and the reference value - conversions, calculations and formulas
- DIN 1320: Acoustics: Terms . Edition 1997-06.