( ( For example ) ( , ( ( a sound ) ( ( must ( ( ( be ( ( ten times ) ( as loud ) ) ) ( as ( another sound ) ) ) ( for ( you ( to ( ( perceive it ) ( as ( twice ( as loud ) ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (IN For) (NP (NN example))) (, ,) (NP (DT a) (NN sound)) (VP (MD must) (VP (VB be) (ADJP (NP (CD ten) (NNS times)) (RB as) (JJ loud)) (PP (IN as) (NP (DT another) (NN sound))) (SBAR (IN for) (S (NP (PRP you)) (VP (TO to) (VP (VB perceive) (NP (PRP it)) (ADVP (RB as) (RB twice) (RB as) (RB loud)))))))) (. .)))
For example, a sound must be ten times as loud as another sound for you to perceive it as twice as loud.
(ROOT (S (NP (NP (DT The) (NN sound)) (PP (IN in) (NP (DT a) (JJ loud) (NN classroom)))) (VP (VBZ is) (NP (NP (DT an) (NN example)) (PP (IN of) (NP (NP (DT a) (NN form)) (PP (IN of) (NP (NN energy))))))) (. .)))