unit, unit of measurement - any division of quantity accepted as a standard of measurement or exchange; "the dollar is the United States unit of currency"; "a unit of wheat is a bushel"; "change per unit volume"

bel, B - a logarithmic unit of sound intensity equal to 10 decibels

dB, decibel - a logarithmic unit of sound intensity; 10 times the logarithm of the ratio of the sound intensity to some reference intensity

sone - a unit of perceived loudness equal to the loudness of a 1000-hertz tone at 40 dB above threshold

phon - a unit of subjective loudness