"Sound power level"@en . . "http://en.wikipedia.org/wiki/Sound_power#Sound_power_level"^^ . "L" . . "Sound Power Level abbreviated as \\(SWL\\) expresses sound power more practically as a relation to the threshold of hearing - 1 picoW - in a logarithmic scale."^^ . "\\(L_W = 10 \\log_{10} \\frac{P}{P_0} dB\\), where \\(P\\) is sound power and the reference value is \\(P_0 =1pW\\)."^^ . . . "belongs to SOQ-ISO" . . .