Mantras are perhaps the most important tools for clearing and cleansing the mind. Mantra helps break up our unconscious and subconscious thought and desire patterns which keep us in bondage to past conditioning. If we observe ourselves we see that all day long there is a background chatter in the mind. It may be the repetition of some song we have heard on the radio, it may be a rehashing of some experience we have just had, an insult or argument for example, or a consideration of what we about to do, but all the time this background noise is going on. It forms the field of our thoughts and serves to drain away our energy of attention.

It is usually not possible for us to directly silence the mind. Our mind is too divided and we have too many unresolved conflicts. It is, however, always within our power to chant a mantra. If we do this regularly, above all, if it becomes our primary mental activity, it gradually replaces this background noise of the mind. Instead of hearing an old song or childhood experience reverberating behind our surface mind, we hear the mantra; Om, Ram, Hare Krishna or whatever it may be. Our subconscious is restructured by the energy of the mantra and ceases to resist the intentions of our conscious mind to meditate. This is the right use of the mantra.

Rightly employed mantras can be used to clear negative emotions from the mind. The mantra Hum, for example, eliminates fear. The mantra Ram gives peace.

Hence, mantra is also an important part of Yoga psychology. It is the main Yogic tool for deconditioning the mind. It does not require any elaborate Psychoanalysis but only an ongoing practice. Through it we can change the structure of the mind that allows psychological problems to exist in the first place. In this way we change the nature of the mind rather than merely analyse it (which does not have the power to fundamentally change it anyway). As long as our thoughts are not mantric we are bound to have some emotional problems in life. The solution is not to study our emotions but to practice the mantra. It is the personal or egoistic energisation of the mind which causes mental suffering. The spiritual energisation of the mind through mantra is the antidote.

Mantra thus leads us to meditation and silence. It is not an end in itself to repeat a sound. Hence, we should remain open after our repetition of the mantra to that stillness of mind and learn to dwell in it. This is where the Om vibration leads us. The sound of the waves merges us back into the silent depths of the ocean.

Quoted from "From the River of Heaven" by David Frawley