( ( Loudness ( of sound ) ) ( ( is ( measured ( in ( ( decibels ( -LRB- ( dB -RRB- ) ) ) ( which ( is ( ( a ( logarithmic comparison ) ) ( of ( two intensities ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NNS Loudness)) (PP (IN of) (NP (NN sound)))) (VP (VBZ is) (VP (VBN measured) (PP (IN in) (NP (NP (NNS decibels)) (PRN (-LRB- -LRB-) (NP (NN dB)) (-RRB- -RRB-)) (SBAR (WHNP (WDT which)) (S (VP (VBZ is) (NP (NP (DT a) (JJ logarithmic) (NN comparison)) (PP (IN of) (NP (CD two) (NNS intensities))))))))))) (. .)))
Loudness of sound is measured in decibels (dB) which is a logarithmic comparison of two intensities.
(ROOT (S (NP (NNP Decibel)) (VP (VBZ is) (NP (NP (DT the) (NN term)) (VP (VBN used) (S (VP (TO to) (VP (VB measure) (NP (NP (DT the) (NN intensity)) (PP (IN of) (NP (JJ sound) (NNS waves)))))))))) (. .)))