coo vs howl

coo

verb
  • To make a soft murmuring sound, as a pigeon. 

  • To speak in an admiring fashion, to be enthusiastic about. 

intj
  • An expression of approval, fright, surprise, etc. 

adj
  • Cool. 

noun
  • The murmuring sound made by a dove or pigeon. 

  • An expression of pleasure made by a person. 

howl

verb
  • To make a noise resembling the cry of a wild beast. 

  • To utter a loud, protracted, mournful sound or cry, as dogs and wolves often do. 

  • To utter a sound expressive of pain or distress; to cry aloud and mournfully; to lament; to wail. 

  • To utter with outcry. 

noun
  • Any similar sound. 

  • A prolonged cry of distress or anguish; a wail. 

  • The protracted, mournful cry of a dog, wolf or other canid; also of other animals. 

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