churr vs hiss

churr

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

noun
  • A low vocal sound made by some birds. 

hiss

verb
  • To make a hissing sound. 

  • To call someone by hissing. 

  • To condemn or express contempt (for someone or something) by hissing. 

  • To utter (something) with a hissing sound. 

  • To whisper, especially angrily or urgently. 

  • To emit or eject (something) with a hissing sound. 

  • To move with a hissing sound. 

noun
  • A sibilant sound, such as that made by a snake or escaping steam; an unvoiced fricative. 

  • An expression of disapproval made using such a sound. 

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