How Does Muntra Chanting Work?

Muntra chanting is useful in spiritual life. How does it work? I will not say much about it here. It's a very big subject. Two aspects of it i will mention, first of all, the psychological aspect. And the second one is the mystical aspect. The psychological aspect is very powerful. Our whole problem is in controlling the mind. We may have good intentions but because the mind itself is flickering, all these intentions are swept away. Real problem is with the flickering of the mind.