drone vs phonation

drone

noun
  • A humming or deep murmuring sound. 

  • One of the fixed-pitch pipes on a bagpipe. 

  • One who performs menial or tedious work. 

  • A person without the ability to think critically and independently, especially one who follows a group blindly; a non-player character. 

  • A remotely controlled aircraft, an unmanned aerial vehicle (UAV). 

  • A Toyota HiAce or a similar van, especially one used by Ugandan state agents to kidnap opposition members. 

  • A male ant, bee or wasp, which does not work but can fertilize the queen. 

  • A genre of music that uses repeated lengthy droning sounds. 

  • A low-pitched hum or buzz. 

verb
  • To speak in a monotone way. 

  • To produce a low-pitched hum or buzz. 

  • To kill with a missile fired by unmanned aircraft. 

phonation

noun
  • The process of producing vocal sound by the vibration of the vocal folds that is in turn modified by the resonance of the vocal tract. 

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