vowel vs vowelize

vowel

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

noun
  • A sound produced by the vocal cords with relatively little restriction of the oral cavity, forming the prominent sound of a syllable. 

  • A letter representing the sound of vowel; in English, the vowels are a, e, i, o, u, and y. 

vowelize

verb
  • To insert a vowel or vowels into. 

  • To give the quality, sound, or office of a vowel to. 

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