I thought to add a little more, If one goes back to ancient Egyptian writings we see there too back then emphasis on sound. On words of power, of the importance of this but comming forth from the desire of the 'heart' by the power of the will, spoken by the tongue creation is manifest.
There comes into being in the heart.
There comes into being by the tongue.
(It is) as the image of Atum.
Ptah is the very great, who gives life to all the gods and their ka's. Lo, through this heart and this tongue. (Gods = Chakras here I believe)
The vibration of the words shaped by the desire, empowered by the Soul (Chi, energy) envisioned in the mind, expressed through the breath and the sound that comes forth directed and cemented by the Will to manifest.
The creation of the expressed sound of words comming from within and the breath these words travel upon carries the energy of the Soul.
When we vibrate words of power into the Chakras we adjust the sound, the pitch until we feel it there you know when it is right. This is when the vibration connects the right way with the energy of the Chakra.
Words created and spoken by Gods have great power and the teachings of this are all through our past and even the acousitics of Temples and Pyramids were designed just so to fine tune that vibration even further.
We best understand the power sound has from music. I enjoy musicals and theatre a bit of Opera it is a more recently aquired taste. Some songs, sung by just the right person who understands and feels what the music is to express can put such power into this peice to make it stick in your mind and ears like superglue and you never forget it, the music carries such energy it has such an impact. A lot goes on when a person hears a song it can incite any emotion pull up memories long forgoten, it can inspire or it can depress. It is so personal because music is vibration. We all vibrate a little differently and what feel and sounds good to one, may not to another and the music also carries emotion. It may mean everything to you. I hate hearing a song I love sung by someone else and done wrong, or without the same feel and emotion. Sometimes it is not just the song or the words but the energy of the one singing it.
It is the vibration of the sound plus the energy put into it by the one who makes the sound. When words of power are vibrated just right with the feel behind them, not just as empty words recited but words expressed with a passion in them this adds to the power. If you find yourself getting tired and bored and just repeating because you must you will not have the effect and be wasting your time.
The soul behind the voice, the Spiritual WITH the physical and the desire. The desire for the outcome that you are working towards.
I hope that made sense, I appologise if it didn't.
Hail Satan