audible vs voiceless

audible

noun
  • The act of or an instance of changing the play at the line of scrimmage by yelling out a new one. 

verb
  • To change the play at the line of scrimmage by yelling out a new one. 

adj
  • Able to be heard. 

voiceless

adj
  • Spoken without vibration of the vocal cords; unvoiced, surd, breathed. Examples: [t], [s], [f], [m̥], [u̥]. 

  • Without a vote; having no input into a decision. 

  • Lacking a voice, without vocal sound. 

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