waul vs yelp

waul

verb
  • To wail, to cry plaintively. 

yelp

verb
  • To utter an abrupt, high-pitched noise. 

noun
  • An abrupt, high-pitched noise or utterance. 

  • A type of emergency vehicle siren sounding quicker and more intense than the wail. 

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