addressee vs collocutor

addressee

noun
  • A person or entity to whom discourse is directed, or the words referring to such an entity. 

  • The person or organization to which something, such as a letter or message, is addressed or sent, for whom the item is intended. 

collocutor

noun
  • Any of the people engaged in a conversation 

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