voice box vs organ of speech

voice box and organ of speech both are nouns.

Word	Noun	Adjective	Verb	Adverb
voice box	Yes	No	No	No
organ of speech	Yes	No	No	No

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

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

Other hypernyms of voice box include speech organ, vocal organ, cartilaginous structure.

voice box (noun)	organ of speech (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