cheeping vs chirr

cheeping

noun
  • The sound of a cheep. 

chirr

noun
  • The trilled sound made by an insect. 

verb
  • To make the prolonged trilling sound of an insect (e.g. a grasshopper, a cicada). 

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