aura vs mien

aura

noun
  • Distinctive atmosphere or quality associated with something. 

  • Telltale sensation experienced by some people with epilepsy before a seizure. 

  • An invisible force surrounding a living creature. 

  • Perceptual disturbance experienced by some migraine sufferers before a migraine headache. 

mien

noun
  • A specific facial expression. 

  • Demeanor; facial expression or attitude, especially one which is intended by its bearer. 

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