speech organ vs vocal organ

speech organ and vocal organ both are nouns.

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

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

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

Other synonyms of speech organ include organ of speech.

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