churr vs thump

churr

verb
  • To make the low vocal sound of some birds. 

noun
  • A low vocal sound made by some birds. 

thump

verb
  • To throb with a muffled rhythmic sound. 

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

  • To cause to make a thumping sound. 

  • 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 churr and thump occurred in a corpus of books? (source: Google Ngram Viewer )