"Mantra is the main and most direct Ayurvedic tool for healing the mind" - David Frawley
The significance of the spoken word is something which spans across a great many ancient cultures & wisdom traditions.
In the Yoga tradition, Sanskrit Mantra is seen as one of the most effective and direct tools for enticing the mind into a state of meditation, and a deeper connection to self and nature. Bhakti Yoga is the practice of devotion, using mantra and intention to reconnect to the heart. While in ancient Ireland, the spoken word (as Gaeilge, usually in the form of poems or incantations) was a way of relating to nature, the landscape, and the way in which beliefs, ideologies & affections were shared. Many devotional practices in the Celtic tradition revolved around the recitation of specific sounds and songs.
When practiced alone or in a group setting (& with intention), mantra has the power to create a space of deep clarity, ease & receptivity - the ideal conditions from which a calm, balanced life can unfold!
Interestingly, when we start to look closer at the stories of the Vedic Gods & Goddesses - who they are, what they represent, and why we'd sing mantras about them - we start to see parallels between this and our own Celtic and Indo-European origins.