larynx vs speech organ

larynx and speech organ both are nouns.

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

As nouns, speech organ is a hypernym of larynx; that is, speech organ is a word with a broader meaning than larynx:

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

Other hypernyms of larynx include organ of speech, vocal organ, cartilaginous structure.

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