growling vs vocalization

growling and vocalization both are nouns.

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

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

growling: a gruff or angry utterance (suggestive of the growling of an animal)
vocalization: the use of uttered sounds for auditory communication

Other hypernyms of growling include utterance.

growling (noun)	vocalization (noun)
a gruff or angry utterance (suggestive of the growling of an animal)	the sound made by the vibration of vocal folds modified by the resonance of the vocal tract
the sound of growling (as made by animals)	the use of uttered sounds for auditory communication