sound power level - total energy per second emitted by the source of sound
sound power level, sound pressure level - the logarithm of the ratio of a given sound power to the reference sound power. Power level in decibels is ten times the logarithm to the base ten of the ratio.
... 'airborne noise emitted' means the A-weighted sound power level, LWA, of the household appliance, expressed in decibels (dB) with reference to the sound power of one picowatt (1 pW), transmitted by the air.