chirl vs thump

chirl

verb
  • To emit a low sound; to warble. 

noun
  • A kind of musical warble. 

thump

verb
  • To cause to make a thumping sound. 

  • To throb with a muffled rhythmic sound. 

  • To hit (someone or something) as if to make a thump. 

  • To thud or pound. 

noun
  • A blow that produces a muffled sound. 

  • The sound of such a blow; a thud. 

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