Wongsifu, Repulsive Monkey, Mantis, TjD, etc.

[prana]

Om Ah Hum

I wont need to introduce these symbols to you guys (or girls if anyone else is here)... I am wondering if anyone uses the sounds to "energise" energy centers ? And if you do how so ?

I have been doing a fair bit of chanting out loud and it works well, especially the 6 syllable Om Mani Padme Hum mantra and the vibrations flow appropriately down ... and although I tend to practise whatever is taught to me faithfully, I am curious at how the sound actually energises the appropriate chakras ? Rinponchela has never said to chant outloud (not explicitly) though he does, but I know some schools of thought say so explicitly....eg.

My first master taught that chanting it like singing (Namo Amitofo) aloud is good, but I couldnt understand why. I am curious in terms of the "chanting out loud" reason. He was a great Qi-Gong grandmaster, but he emphasises chanting this mantrum aloud.
And at what tone ? Like what if a girl was to chant the same mantrum, would the vibrations be different ? Why do the yogis who meditate specifically on these syllables have extremely deep voices ? (and how it brings much peace to myself personally to hear the chants)
Also Brahmans believe this Om to be chanted out loud and meditated upon. Why so why such ? How does that affect the prana (Qi)

Thanks guys....