incant vs vocalize

incant

verb
  • To state solemnly, to chant. 

  • To recite an incantation. 

vocalize

verb
  • To express with the voice, to utter. 

  • To sing without using words. 

  • To produce noises or calls from the throat. 

  • To add vowel points to a consonantal script (e.g. niqqud in Hebrew) 

  • To turn a consonant into a vowel. 

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