announce vs listen

announce

verb
  • to give public notice, especially for the first time; to make known 

  • to pronounce; to declare by judicial sentence 

listen

verb
  • To pay attention to a sound or speech. 

  • To expect or wait for a sound, such as a signal. 

  • To accept advice or obey instruction; to agree or assent. 

noun
  • An instance of listening. 

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