moan vs ululate

moan

verb
  • To make a moan or similar sound. 

  • To complain; to grumble. 

  • To say in a moan, or with a moaning voice. 

  • To grieve. 

noun
  • a low, mournful cry of pain, sorrow or pleasure 

ululate

verb
  • to howl loudly or prolongedly in lamentation or joy 

  • to produce a rapid and prolonged series of sharp noises with one's voice. 

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