contralto vs vocaliser

contralto and vocaliser both are nouns.

Word	Noun	Adjective	Verb	Adverb
contralto	Yes	Yes	No	No
vocaliser	Yes	No	No	No

As nouns, vocaliser is a hypernym of contralto; that is, vocaliser is a word with a broader meaning than contralto:

Other hypernyms of contralto include singer, vocalist, vocalizer.

contralto (noun)	vocaliser (noun)
the lowest female singing voice	a person who sings
a woman singer having a contralto voice	an organism that can utter vocal sounds

contralto (adjective)	vocaliser (adjective)
of or being the lowest female voice