vowelise vs sound out

vowelise and sound out both are verbs.

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

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

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

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