Sound power, sound pressure level and sum decibels
Sound power, sound pressure level and sum decibels
LW = Sound power level in dB
W = Acoustic power we want to know in Watts
Wref = Acoustic reference power 1*10 ^ (- 12) [W]
NPS = Sound pressure level in dB
P = Pressure we want to know in Pascals
P0 = Reference pressure 2*10 ^ (- 5) [Pa]
To add decibels, being logarithmic values, it is not done in the same way as the arithmetic sum, for that there is the expression:
NPS = Sound pressure level in dB
L1 = First source to add
L2 = Second source to addLN = N source to add
References:
Ac煤stica Integral. (s.f.). Potencia ac煤stica. Recuperado de https://www.acusticaintegral.com/3307/frecuencia-espectros-octavas-y-tercios-de-octava/
Inerco Ac煤stica. (2012). ¿C贸mo se suman las fuentes sonoras (suma de dB)?. Recuperado de https://www.inercoacustica.com/acustipedia/item/233-%C2%BFc%C3%B3mo-se-suman-las-fuentes-sonoras-suma-de-db
MotorGiga. (s.f.). DECIBEL Qu茅 es. Recuperado de https://diccionario.motorgiga.com/decibel
- In this video i talk about how to obtain sound power, sound pressure level and sum decibels with two little examples
The sound power (Integral Acoustics, n.d.) is defined as the amount of energy per unit of time that is emitted by a given audio source, this is expressed in Watts [W] and serves to characterize a source by being an intrinsic parameter of the same, this is generally given by the manufacturer of the sound equipment in the technical data sheets, while the sound power level is the magnitude that is used to express the acoustic power of a sound source and is expressed in decibels and calculate with the equation:
LW=10log(W/Wref) dB
LW = Sound power level in dB
W = Acoustic power we want to know in Watts
Wref = Acoustic reference power 1*10 ^ (- 12) [W]
The sound pressure corresponds to the movement of the air caused by the sound waves, being very small quantities to be measured in Pascals [Pa], the decibel is used (Inerco Ac煤stica, 2012), which is the unit (MotorGiga, sf) used To buy two sound pressure values as a convention, the following equation is used to convert Pascales to sound pressure:
NPS=20log(P/P0) dB
NPS = Sound pressure level in dB
P = Pressure we want to know in Pascals
P0 = Reference pressure 2*10 ^ (- 5) [Pa]
To add decibels, being logarithmic values, it is not done in the same way as the arithmetic sum, for that there is the expression:
NPS=10log(10^(L1/10))+10log(10^(L2/10))+...+10log(10^(LN/10)) dB
NPS = Sound pressure level in dB
L1 = First source to add
L2 = Second source to addLN = N source to add
Cjp24 [CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0)]
References:
Ac煤stica Integral. (s.f.). Potencia ac煤stica. Recuperado de https://www.acusticaintegral.com/3307/frecuencia-espectros-octavas-y-tercios-de-octava/
Inerco Ac煤stica. (2012). ¿C贸mo se suman las fuentes sonoras (suma de dB)?. Recuperado de https://www.inercoacustica.com/acustipedia/item/233-%C2%BFc%C3%B3mo-se-suman-las-fuentes-sonoras-suma-de-db
MotorGiga. (s.f.). DECIBEL Qu茅 es. Recuperado de https://diccionario.motorgiga.com/decibel
How to cite this article:
Nocetti, F.A. (2018). "Sound power". In NabbuBlog. Retrieved from http://nabbublog.blogspot.com/2018/10/sound-power-sound-pressure-level-and.html