“Vac’s themes are purification, protection, offerings and communication. Her symbols are the spoken word and fresh flowers. The Balinese/Hindu Goddess of charms and incantations, Vac joins today’s celebrations using Her powers to banish any lingering shadows or negativity from our lives. Traditionally, Vac is present in any sacred words that convey occult power or knowledge. This is especially true of mantras that reaffirm, sustain, and shelter one’s soul.
Artistic renderings reveal Vac as a mature, graceful woman bedecked in gold (an allusion to solar energy). She sometimes also appears as a cow, which is Her mother-Goddess aspect.
Bali legends say that hellish beings roam freely during this time of year, so everyone cleanses themselves and the land through magic and supplications. In this spirit, periodic spiritual ‘house cleaning’ is a good habit to get into, especially if you live in the city. Leave an offering of flowers on your altar, saying Vac’s name as you put them out. This begins the process of purging any clinging bad vibes and restoring your home’s sanctity.
Use noise makers to chase out any male-intended magic or spirits. Burn sweet-smelling incense to welcome Vac to your home, saying:
‘Vac, charge my speech with security
so no darkness can dwell in my home or me
Vac, be welcome in and through my words
Let the magic ever be heard!'”
(Patricia Telesco, “365 Goddess: a daily guide to the magic and inspiration of the goddess”.)
“Vāk or Vāc is the Sanskrit word for “speech”, “voice”, “talk”, or “language”, from a verbal root vac- “speak, tell, utter”. Personified, Vāk is a Goddess; most frequently She is identified with Bharati or Sarasvati, the Goddess of speech. In the Veda She is represented as created by Prajapati and married to him; in other places She is called the mother of the Vedas, having inspired the sages to write them, and wife of Indra. In certain texts She is a daughter of Daksa and the consort of Kasyapa. Alternatively She is the daughter of Ambhrna, and, also, is known by the epithet “queen of the gods” and is believed to be able to lead a man to become a Brahman. Vac also personifies truth and sustains soma, the liquid essence of vision and immortality.” 
“She is described in the Rig Veda as not only speech itself, but also as truth and perception, which allows us to turn divine knowledge into words. Vac’s name is also seen as Vak or Vach, and sacred texts give Her the following names… She is generally depicted as an elegant golden-skinned woman, dressed in gold; but in a secondary capacity as a mother Goddess, She is depicted as a cow, a symbol of nourishment.” 
“This Hindu Goddess’ manifestation is thought to have come from the early reliance on the sacred oral teachings “heard” by the rsis (holy men) properly intoned and accented, thrust the folk-divinity Vac into prominence. Since effective service depended upon effective speech, the supreme vehicle of knowledge and ritual power… Vac even gained precedence over Agni. As the “Word,” Vac is somewhat like the Neo-platonic “logos“: Vac is the source of creation, and the mother of the Veda. In the Tantric tradition She is celebrated as Para-vac, Transcendental speech, the mother of all sacred mantras.
Vac, although prominent in the Rig Veda, almost completely disappears from Hindu mythology later when being syncretized with the river Goddess Sarasvati, whose banks of the sacred river served as fertile soil for the growth of brahmanical culture.” 
Sabrina. Goddess A Day, “Vac“.
Kinsley, David. Hindu Goddesses: Visions of the Divine Feminine in the Hindu Religious Tradition, “Vāc“.
Sitarik, Jessica. Crystal Vaults, “Vac: Hindu Goddess of Written Words and Wisdom“.