sound out vs talk

sound out is not a noun while talk is a noun.

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

sound out (noun)	talk (noun)
	the act of giving a talk to an audience
	an exchange of ideas via conversation
	idle gossip or rumor
	a speech that is open to the public
	discussion; (`talk about' is a less formal alternative for `discussion of')

sound out (verb)	talk (verb)
try to learn someone's opinions and intentions	express in speech
speak, pronounce, or utter in a certain way	exchange thoughts; talk with
	reveal information
	use language
	deliver a lecture or talk
	divulge confidential information or secrets