chorister vs vocalizer

chorister and vocalizer both are nouns.

Word	Noun	Adjective	Verb	Adverb
chorister	Yes	No	No	No
vocalizer	Yes	No	No	No

As nouns, vocalizer is a hypernym of chorister; that is, vocalizer is a word with a broader meaning than chorister:

Other hypernyms of chorister include singer, vocaliser, vocalist.

chorister (noun)	vocalizer (noun)
a singer in a choir	a person who sings
	an organism that can utter vocal sounds