We were playing all sorts of sports, and you were not, so shut up and stop twitching,' the microbe's tone of voice changed, it was lower and more resounding.
( ( ( ( ( We ( were ( playing ( ( all sorts ) ( of sports ) ) ) ) ) , ) and ) ( you ( ( ( were not ) ( , ( ( ( so ( shut up ) ) and ) ( stop ( twitching ( , ( ' ( ( ( the ( microbe 's ) ) tone ) ( of voice ) ) ) ) ) ) ) ) ) changed ) ) ) ( , ( it ( ( was ( ( lower and ) ( more resounding ) ) ) . ) ) ) )
(ROOT (S (S (S (NP (PRP We)) (VP (VBD were) (VP (VBG playing) (NP (NP (DT all) (NNS sorts)) (PP (IN of) (NP (NNS sports))))))) (, ,) (CC and) (S (NP (PRP you)) (VP (VBD were) (RB not) (PRN (, ,) (S (VP (VP (ADVP (RB so)) (VB shut) (PRT (RP up))) (CC and) (VP (VB stop) (UCP (ADJP (JJ twitching)) (, ,) ('' ') (NP (NP (NP (DT the) (NN microbe) (POS 's)) (NN tone)) (PP (IN of) (NP (NN voice))))))))) (ADJP (JJ changed))))) (, ,) (NP (PRP it)) (VP (VBD was) (ADJP (ADJP (JJR lower)) (CC and) (ADJP (RBR more) (JJ resounding)))) (. .)))
The microbe's tone was now lower than it previously had been. 
( ( ( The ( microbe 's ) ) tone ) ( ( ( ( was now ) lower ) ( than ( it ( previously ( had been ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (NN microbe) (POS 's)) (NN tone)) (VP (VBD was) (ADVP (RB now)) (ADJP (JJR lower)) (SBAR (IN than) (S (NP (PRP it)) (ADVP (RB previously)) (VP (VBD had) (VP (VBN been)))))) (. .)))