The use of sound is a key part of ceremonial magick. One theory claims that the vibration set up by a mantra has a purifying effect on the whole constitution of a person; that by its vibrating action the coarser elements in the body are gradually expelled, a refining process taking place which affects not only the physical body, but also the Body of Light and the entire mental structure within the scope of its actions.
A simple example of the power of sound and vibration can be seen in the opera singer who yaps a glass and then matches the note with their voice. After a moment, when the voice is vibrating in unison with the galls, the singer suddenly changes the note to a higher one and wine galls shatters as it tries to match the vibration.
And so the vibration of God-names is an important essential in the practice of magick since the knowledge (and by knowledge I also mean understanding) of the name is to possess a degree of control over it. But it is essential that the name is properly vibrated for it take effect.
To do this, inhale very deeply, slowly and forcefully. At the moment when the air strikes against the nostrils, it should be imagined that the name of the god (or word of power) is being inhaled with the air. Picture the name in great letters of fire and flame, and as the air slowly fills the lungs, the name should be imagined to permeate and vibrate throughout the whole of the body. Then the god name is vibrated as the air is exhaled. That is to say, one must discover the method or humming of pronouncing the words which will assist in producing a vibration. It may be found through experiment that a moderately deep pitch, slightly higher than the ordinary speaking voice is most suited to produce the required vibration, no-one part being accented at the expense of another. The test of the vibration is that it should detonate in the palms of the hands and the soles of the feet.
It is difficult to explain this without demonstrating how it should be done. But it will be clear when this is done correctly as a tingling sense will be felt in every cell and nerve of the body.
