Sound energy
Appearance
Sound measurements | |
---|---|
Characteristic | Symbols |
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 |
Inphysics,sound energyis a form of energy that can beheardby living things. Only those waves that have a frequency of 16 Hz to 20 kHz are audible to humans. However, this range is an average and will slightly change from individual to individual. Sound waves that have frequencies below 16 Hz are calledinfrasonicand those above 20 kHz are calledultrasonic.Soundis amechanical waveand as such consists physically inoscillatoryelasticcompressionand in oscillatory displacement of afluid.Therefore, themediumacts asstoragefor bothpotentialandkinetic energy.[1]
Consequently, the sound energy in a volume of interest is defined as the sum of the potential and kineticenergy densitiesintegrated over that volume:
where
- Vis the volume of interest;
- pis thesound pressure;
- vis theparticle velocity;
- ρ0is thedensityof the medium without sound present;
- ρis the localdensityof the medium; and
- cis thespeed of sound.
See also
[edit]References
[edit]- ^Möser, M.; Müller, G. (2012).Handbook of Engineering Acoustics.Springer.p. 7.ISBN9783540694601.