twang vs sound out

twang is a noun but sound out is not a noun.

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

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

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

twang (noun)	sound out (noun)
exaggerated nasality in speech (as in some regional dialects)
a sharp vibrating sound (as of a plucked string)

twang (verb)	sound out (verb)
pronounce with a nasal twang	try to learn someone's opinions and intentions
pluck (strings of an instrument)	speak, pronounce, or utter in a certain way
sound with a twang
cause to sound with a twang
twitch or throb with pain