speech organ vs glottis

speech organ and glottis both are nouns.

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

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

speech organ: any of the organs involved in speech production
glottis: the vocal apparatus of the larynx; the true vocal folds and the space between them where the voice tone is generated

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

speech organ (noun)	glottis (noun)
any of the organs involved in speech production	the vocal apparatus of the larynx; the true vocal folds and the space between them where the voice tone is generated