vowelize vs sound out

vowelize and sound out both are verbs.

Word	Noun	Adjective	Verb	Adverb
vowelize	No	No	Yes	No
sound out	No	No	Yes	No

As verbs, sound out is a hypernym of vowelize; that is, sound out is a word with a broader meaning than vowelize:

Other hypernyms of vowelize include articulate, enounce, enunciate, pronounce, say.

vowelize (verb)	sound out (verb)
pronounce as a vowel	try to learn someone's opinions and intentions
	speak, pronounce, or utter in a certain way