is also known as Acoustic Power : LPac : Pac : PWL : PWR : SWL.
The range of human hearing, 0.000000000001 watts to 100 watts or more, means using absolute sound power values is not practical for everyday use. A neat solution is the Sound Power Leveldecibel descriptor.
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.
Sound Power Level : Lw = 10 lg (W/Wo) dB Sound Power Reference Level : Wo = 1 pW = 10-12 W ≡ 0dB
A-weighted sound power level referred to 1 pW of a point source at the rotor center with the same emission in the downwind direction as the wind turbine being measured as determined at the acoustic reference wind speed
● Note : the apparent sound power level is generally expressed in decibels.
Sound Power Equivalent Absorption Area of an Object or of a SurfaceIEC Definition,
area of a surface having a sound power absorption coefficient of unity that would absorb the same amount of sound power in a reverberant room with a diffuse sound field as the object or the surface. In the саsе of a surface, the equivalent absorption area is the product of the area of the surface and its sound power absorption coefficient