commend vs sound off

commend

verb
  • To praise or acclaim. 

  • To recommend. 

  • To entrust or commit to the care of someone else. 

  • To mention by way of courtesy, implying remembrance and goodwill. 

  • To congratulate or reward. 

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 commend and sound off occurred in a corpus of books? (source: Google Ngram Viewer )