ozone vs whisper

ozone

noun
  • Fresh air, especially that breathed at the seaside and smelling of seaweed. 

  • An allotrope of oxygen (symbol O₃) having three atoms in the molecule instead of the usual two; it is a toxic gas, generated from oxygen by electrical discharge. 

  • Hypernym: greenhouse gas 

verb
  • To treat with ozone. 

whisper

noun
  • A low rustling sound, like that of the wind in leaves. 

  • A private message to an individual in a chat room. 

  • A rumor. 

  • A faint trace or hint (of something). 

  • The act of speaking in a quiet voice, especially, without vibration of the vocal cords. 

verb
  • To speak softly, or under the breath, so as to be heard only by one near at hand; to utter words without sonant breath; to talk without that vibration in the larynx which gives sonorous, or vocal, sound. 

  • To speak with suspicion or timorous caution; to converse in whispers, as in secret plotting. 

  • To make a low, sibilant sound. 

  • To mention privately and confidentially, or in a whisper. 

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