let out vs let loose

let out and let loose both are verbs.

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

As verbs, let out and let loose are synonyms defined as:

let out and let loose: express audibly; utter sounds (not necessarily words)

Other synonyms of let out include emit, utter.

let out (verb)	let loose (verb)
make (clothes) larger	express audibly; utter sounds (not necessarily words)
make known to the public information that was previously known only to a few people or that was meant to be kept a secret	turn loose or free from restraint
express audibly; utter sounds (not necessarily words)
bring out of a specific state