consent vs sound off

consent

verb
  • To agree in opinion or sentiment; to be of the same mind; to accord; to concur. 

  • To express willingness, to give permission. 

  • To cause to sign a consent form. 

noun
  • Voluntary agreement or permission. 

sound off

verb
  • To hold forth about something in an opinionated manner. 

  • Command instructing a person to confirm that they are present or that some other objective has been met. 

  • Command instructing a person to speak up or acknowledge something. 

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