( ( A ( loud ( sound amplifier ) ) ) ( ( was ( used ( at ( the ( receiving end ) ) ) ) ) . ) )
(ROOT (S (NP (DT A) (JJ loud) (NN sound) (NN amplifier)) (VP (VBD was) (VP (VBN used) (PP (IN at) (NP (DT the) (NN receiving) (NN end))))) (. .)))
A loud sound amplifier was used at the receiving end.
(ROOT (S (S (VP (VBN Amplified))) (, ,) (NP (PRP it)) (VP (VBZ becomes) (SBAR (S (NP (NNP louder)) (VP (VBZ happens) (VP (VB do) (NP (DT the) (NN sound)) (PP (IN during) (NP (DT a) (NN resonance)))))))) (. .)))