Pranava dhyana

Sri Sadgurubhyoh Namah

VBT 39 :

Pranavaadisamuchchaaraat plutaante shoonyabhaavanaat,

shoonyayaa parayaa shaktyaa shoonyataam yeti bhairavi

Translation :

Perfectly recite Pranava meditating protractedly on the void, experience the void, and by that void experience the transcendental void, O Bhairavi.

Commentary :

Pranava is AUM. It consists of three sounds 'Aa', 'Uu' and 'Mmm'. With each chant of Omkar, these three sounds are recited and the sound is followed by a silence, which is referred to as shoonya (void) in this sutra. Any sound has four levels, Vaikhari (gross physical sound which you can hear with ears), Madhyama (whispering level), pashyanti (mental image associated with sound) and para (cosmic level).

You can practice chanting of Pranava along with the void, at all three levels (vaikhari, madhyama, pashyanti).

The length of duration for each sound in Omkar should be equal. Giving equal time for each sound 'Aa', 'Uu', 'Mmm' and long protracted length of time for listening to the silence that follows the chant of AUM. Silent mind is the gateway to Godliness.

How to do :

a) Vaikhari chanting : Chant Omkara loudly. When you chant 'Aa' observe the lower portion of spinal chord. When you chant 'Uu' observe the middle portion of spinal chord upto neck. When you chant 'Mmm' observe the head region. After the sounds, your mind becomes silent and keep your attention on the crown of head and observe the silence for such length of time, till your mind doesnt start getting disturbed. Then start the next Omkar chanting. Chant minimum 18 rounds in one sitting. 

b) Madhyama : Do the above with low sound, audible only to you in whispering level.

c) Pashyanti : Do the above chanting in your mind, without uttering any sound.

The silence of mind that you gained becomes deeper and deeper, and through that silence you will understand the transcendental Shakti.

You can do all the three a, b, c in one sitting one after the other which gives better results.