doorbell vs tocsin

doorbell

noun
  • A button that activates an electric doorbell. 

  • A device on or adjacent to an outer door for announcing one's presence. It can be mechanical, directly sounding a bell, or a button that electrically sounds a chime or buzzer inside the building. 

verb
  • To ring many doorbells of (target people or an area) in an effort to contact people and thereby spread information or solicit. 

  • To ring many doorbells in an effort to contact people and thereby spread information or solicit. 

tocsin

noun
  • A bell used to sound an alarm. 

  • An alarm or other signal sounded by a bell or bells, originally especially with reference to France. 

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