speech vs vocalization

speech and vocalization both are nouns.

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

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

Other hypernyms of speech include utterance.

speech (noun)	vocalization (noun)
the mental faculty or power of vocal communication	the sound made by the vibration of vocal folds modified by the resonance of the vocal tract
(language) communication by word of mouth	the use of uttered sounds for auditory communication
the act of delivering a formal spoken communication to an audience
words making up the dialogue of a play
a lengthy rebuke
the exchange of spoken words
your characteristic style or manner of expressing yourself orally
something spoken