yodeller vs vocaliser

yodeller and vocaliser both are nouns.

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

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

yodeller: a singer who changes register rapidly (popular in Swiss folk songs)
vocaliser: a person who sings

Other hypernyms of yodeller include singer, vocalist, vocalizer.

yodeller (noun)	vocaliser (noun)
a singer who changes register rapidly (popular in Swiss folk songs)	a person who sings
	an organism that can utter vocal sounds