|There is a physical phenomenon known as "harmonic resonance." This simply means that if one object vibrates powerfully enough, another object nearby will start to vibrate (or resonate) with the first if the second object has a natural vibratory rate in harmony with the first. As an example, if a violin note is played near a piano, the piano strings which have certain harmonic relationships to the violin note will sound; they will start to resonate. Thus, if you can control the vibration rate of one object, such as yourself, you will be able to cause certain reactions in other objects, such as those which exist on other planes of existence. Therefore, an understanding of how to vibrate words is essential for a magician.
There are two methods of vibrating words, commonly known as the two vibratory formulae. The first is an internal (invocatory) formula. In this formula you cause a certain part of your body (actually part of your astral body) to vibrate. This is exemplified in the Kabalistic Cross part of the LBRP. Let’s just look at the word AH-TAH. What you should do here is fully inhale until there isn’t room for one more drop of air. Then use the entire exhalation to vibrate the word. Thus, the word is elongated: AAAAHHHHHHH-TAAAAAAHHHH. It should be vibrated loudly in an almost chant-like tone of voice. The pitch is usually higher than the normal pitch of your voice. It is almost shouted. Most importantly, you should feel it vibrate or resonate within your head. Likewise, MAHL-KOOT should be felt in the groin, VIH-G’BOO-RAH in the area of the right shoulder, etc.
The second vibratory method is the external (evocatory) formula. With this formula the intent is to excite the atmosphere (actually the so-called astral plane) around you. This is exemplified in the Formulation of the Pentagrams part of the LBRP. The method is quite similar to the invocatory formula. You inhale fully, and as you exhale you loudly vibrate the appropriate words…The big difference between the two formulae is that in the evocatory formula you should sense that the entire universe in front of you is resonating in harmony with your vibration. Your entire body and the entire universe should be experienced as vibrating to your call...
Some student-magicians do not have the luxury of a place where they can loudly, firmly and authoritatively vibrate the God names and words of power. In fact, they need to keep their work a secret. If you find yourself in such a position, you may use what is disguisedly called the "Great Voice." That is, you may do the vibratory formulae silently or very quietly, perhaps at the level of a whisper or quiet conversation. However, if you do so, you must still experience the vibratory phenomena. You must feel the various parts of your body vibrate when doing the invocatory vibratory formula. You must sense the entire universe resonating in harmony to your use of the evocatory formula. In other words, you must have the same results whether you vibrate loudly or in the Great Voice.