chattering vs chirl

chattering

noun

  • A noise that chatters. 

  • Output fluctuation before reaching a stable condition. 

adj

  • That chatters 

chirl

noun

  • A kind of musical warble. 

verb

  • To emit a low sound; to warble. 

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