sound out vs feel out

sound out and feel out both are verbs.

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

As verbs, sound out and feel out are synonyms defined as:

Other synonyms of sound out include check out.

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