chirp vs let out

chirp is a noun but let out is not a noun.

Word	Noun	Adjective	Verb	Adverb
chirp	Yes	No	Yes	No
let out	No	No	Yes	No

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

Other hypernyms of chirp include emit, let loose, utter.

chirp (noun)	let out (noun)
a sharp sound made by small birds or insects

chirp (verb)	let out (verb)
make high-pitched sounds	make (clothes) larger
sing in modulation	make known to the public information that was previously known only to a few people or that was meant to be kept a secret
	express audibly; utter sounds (not necessarily words)
	bring out of a specific state