vocal organ vs speech organ

vocal organ and speech organ both are nouns.

Word	Noun	Adjective	Verb	Adverb
vocal organ	Yes	No	No	No
speech organ	Yes	No	No	No

As nouns, vocal organ and speech organ are synonyms defined as:

vocal organ and speech organ: any of the organs involved in speech production

Other synonyms of vocal organ include organ of speech.

vocal organ (noun)	speech organ (noun)
any of the organs involved in speech production	any of the organs involved in speech production