vowel system vs vocalism

vowel system and vocalism both are nouns.

Word	Noun	Adjective	Verb	Adverb
vowel system	Yes	No	No	No
vocalism	Yes	No	No	No

As nouns, vowel system and vocalism are synonyms defined as:

vowel system and vocalism: the system of vowels used in a particular language

vowel system (noun)	vocalism (noun)
the system of vowels used in a particular language	the sound made by the vibration of vocal folds modified by the resonance of the vocal tract
	the system of vowels used in a particular language