expiration vs falsetto

expiration

noun
  • That which is produced by breathing out, as a sound. 

  • A cessation, extinction, ending 

  • Emission of volatile matter; exhalation. 

  • The last emission of breath; death. 

  • The act of expiring. 

  • The act or process of breathing out, or forcing air from the lungs through the nose or mouth 

falsetto

noun
  • 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. 

  • A person who sings in falsetto. 

verb
  • To sing or utter in falsetto. 

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