enunciation vs mouthing

enunciation

noun
  • Mode of utterance or pronunciation, especially as regards fullness and distinctness or articulation. 

  • That which is enunciated or announced; words in which a proposition is expressed; formal declaration 

  • The act of enunciating, announcing, proclaiming, or making known; open attestation; declaration. 

mouthing

noun
  • The act of forming a shape with the mouth, especially as part of sign language. 

  • Ranting; passionate speech devoid of meaning. 

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