noun (n)

• the system of vowels used in a particular language(noun.communication)

  Synonym:
  vowel system
  

  source: wordnet30
• the sound made by the vibration of vocal folds modified by the resonance of the vocal tract(noun.communication)

  Synonym:
  phonation, vocalisation, vocalization, voice, vox
  

  source: wordnet30
• The exercise of the vocal organs; vocalization.(noun)

  source: webster1913