meep vs warning bell

meep

noun
  • A high-pitched exclamation of fear or concern. 

verb
  • to make a high-pitched exclamation 

intj
  • expressing surprise, dismay, fear, or concern 

  • imitating a small animal's cry, particularly a kitten or small bird 

  • imitating a small vehicle's high pitched horn 

warning bell

noun
  • A problematic or alarming aspect. 

  • A bell rung to warn people of a danger. 

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