utterance vs vocalization

utterance and vocalization both are nouns.

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

As nouns, utterance and vocalization are synonyms defined as:

utterance and vocalization: the use of uttered sounds for auditory communication

utterance (noun)	vocalization (noun)
the use of uttered sounds for auditory communication	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