churr vs shrill

churr

noun
  • A low vocal sound made by some birds. 

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

shrill

noun
  • A shrill sound. 

verb
  • To make a shrill noise. 

adj
  • Sharp or keen to the senses. 

  • Having a shrill voice. 

  • Fierce, loud, strident. 

  • High-pitched and piercing. 

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