vocalism vs vowel system

vocalism and vowel system both are nouns.

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

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

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

vocalism (noun)	vowel system (noun)
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
the system of vowels used in a particular language