babble vs falsetto

babble

verb
  • To utter in an indistinct or incoherent way; to repeat words or sounds in a childish way without understanding. 

  • To reveal; to give away (a secret). 

  • To utter words indistinctly or unintelligibly; to utter inarticulate sounds 

  • To talk incoherently; to utter meaningless words. 

  • To talk too much; to chatter; to prattle. 

  • To make a continuous murmuring noise, like shallow water running over stones. 

noun
  • A sound like that of water gently flowing around obstructions. 

  • Idle talk; senseless prattle 

  • Inarticulate speech; constant or confused murmur. 

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 babble and falsetto occurred in a corpus of books? (source: Google Ngram Viewer )