bleat vs falsetto

bleat

verb
  • Of a sheep or goat, to make its characteristic cry; of a human, to mimic this sound. 

  • Of a person, to complain. 

noun
  • The characteristic cry of a sheep or a goat. 

falsetto

verb
  • To sing or utter in falsetto. 

noun
  • A person who sings in falsetto. 

  • The "false" (singing) voice in any human, usually airy and lacking a purity of vowels; created by utilizing the next highest vocal folds above those used for speech and normal range singing. It is commonly confused with the head voice register. 

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