preachify vs sound off

preachify

verb
  • To preach didactically; to sermonize. 

sound off

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

  • 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. 

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