roll call vs vocalization

roll call and vocalization both are nouns.

Word	Noun	Adjective	Verb	Adverb
roll call	Yes	No	No	No
vocalization	Yes	No	No	No

As nouns, vocalization is a hypernym of roll call; that is, vocalization is a word with a broader meaning than roll call:

Other hypernyms of roll call include utterance.

roll call (noun)	vocalization (noun)
calling out an official list of names	the sound made by the vibration of vocal folds modified by the resonance of the vocal tract
	the use of uttered sounds for auditory communication