aftersound vs thudding

aftersound

noun
  • A sound that persists or remains audible after its source has ceased to produce it; the perception of such a sound. 

  • The second, slower phase of decay in the sound made by a piano string when it is struck. 

thudding

noun
  • A dull banging sound; a thud. 

How often have the words aftersound and thudding occurred in a corpus of books? (source: Google Ngram Viewer )