listener vs readership

listener

noun
  • Someone who listens, especially to a speech or a broadcast. 

  • A musical anthology. 

  • A function that runs in response to an event; an event handler. 

  • A person's ear. 

readership

noun
  • The role or office of a reader. 

  • The collected readers of a publication. 

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