speech organ vs larynx

speech organ and larynx both are nouns.

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

As nouns, larynx is a hyponym of speech organ; that is, larynx is a word with a more specific, narrower meaning than speech organ:

speech organ: any of the organs involved in speech production
larynx: a cartilaginous structure at the top of the trachea; contains elastic vocal cords that are the source of the vocal tone in speech

Other hyponyms of speech organ include articulator, glottis, voice box.

speech organ (noun)	larynx (noun)
any of the organs involved in speech production	a cartilaginous structure at the top of the trachea; contains elastic vocal cords that are the source of the vocal tone in speech