( ( ( The sound ) ( of ( her sucking ) ) ) ( ( ( ( seemed loud ) , ) ( amplified ( by ( ( the ( hard walls ) ) ( of ( the cellar ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (NN sound)) (PP (IN of) (NP (PRP$ her) (NN sucking)))) (VP (VBD seemed) (ADVP (JJ loud)) (, ,) (S (VP (VBN amplified) (PP (IN by) (NP (NP (DT the) (JJ hard) (NNS walls)) (PP (IN of) (NP (DT the) (NN cellar)))))))) (. .)))
The sound of her sucking seemed loud, amplified by the hard walls of the cellar.
(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)))))))) (. .)))