Sound Power is also known as Acoustic Power : LPac : Pac : PWL : PWR : SWL.
The range of human hearing is 0.000000000001 watts to 100 watts or more, so sound power values in watts is not practical for everyday use. However the sound power level in decibels - discussed below, neatly solves this problem.See also power quantity • root power (field) quantity
Sound Power Level (Lw) = 10 lg (W/Wo) dB
Sound Power Reference Level (Wo) = 1 pW = 10-12 W ≡ 0 dB
|Source||Sound Power W||Lw re 1 pW|
|Jet Engine||10,000 W||160 dB|
|Loudspeaker Rock||100 W||140 dB|
|2 Pneumatic hammers||2 W||123 dB|
|Pneumatic hammer||1 W||120 dB|
|Outboard motor||0.01 W||100 dB|
|Dishwasher||0.0001 W||80 dB|
|Office||0.000001 W||60 dB|
|Fridge||0.00000001 W||40 dB|
|Whisper||0.0000000001 W||20 dB|
|Threshold||10-12 W||0 dB|
10 dB = a factor of 10 in sound power
20 dB = a factor of 100 in sound power
30 dB is a factor of 1000
40 dB is a factor of 10000
Sound Power Level Definition IEC 801-22-05, logarithm of the ratio of a given sound power to the reference sound power. Such power level in decibels is ten times the logarithm to the base ten of the ratio.
● Note : unless otherwise specified, the reference sound power is 1 pW.
Related Terms - listed alphabetically
● Note : the acoustic reference speed is generally expressed in meters per second.
● Note : the apparent sound power level is generally expressed in decibels.
● Note : unless otherwise specified, a diffuse sound field is to be understood.
Sound Power Density Definition IEC 801-21-38, sound energy flux in a specified direction and sense through an area perpendicular to that direction, divided by the area. Also known as sound intensity and sound energy flux density.
● Note : unless otherwise specified, random incidence is presumed.
Sound Power Through A Surface Element Definition IEC 801-21-37, time average product of the in-phase components of the instantaneous sound pressure and the volume velocity through the surface element considered, and is also known as the sound energy flux
See also sound power absorption coefficient