groan vs vocalization

groan and vocalization both are nouns.

Word	Noun	Adjective	Verb	Adverb
groan	Yes	No	Yes	No
vocalization	Yes	No	No	No

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

Other hypernyms of groan include utterance.

groan (noun)	vocalization (noun)
an utterance expressing pain or disapproval	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

groan (verb)	vocalization (verb)
indicate pain, discomfort, or displeasure