Now, each of these chakras starting from the Mooladhara to the Sahasrara also have their associative sounds which are known as the bijaksharas–seed sounds. The lowest Mooladhara chakra is associated with the sound–lung. It is not lun, it’s not lum but somewhere in between–lung. So, lung is the sound associated with or is the bijakshara of the Mooladhara chakra. When the yogi fixes his attention on the Mooladhara and continuously chants the lung, the energy is supposed to activate or awaken the chakra.
The sound or bijakshara of the next chakra–the Swadisthana chakra is wung. The sound of the Manipura chakra is rung. Rung is the sound of Aruna or the fire. The bijakshara of the Anahatha chakra is yung. Anahatha chakra at the center of the chest is activated by the sound of yung. The seed sound or the bijakshara of the throat chakra–the Vishuddha chakra–is humng. You know it is the great bijakshara of the Buddhist mantra; most of the Tibetan Buddhist mantras have the sound of humng. It is the sound of the Vishuddha chakra or the chakra of purity. For instance, consider the famous mantra–’Om mani padme humng’. Humng is the sound.
Then, the Agya chakra and the Sahasrara chakra are together covered by the sound of pranava–aum. So, when you say aum, it covers both the Agya at the eyebrow’s centre and the Sahasrara chakra or the crown chakra. So, these are the bijaksharas. So, when we chant it from the Mooladhara upwards, it is in the order of lung, wung, rung, yung, humng and aum.
Now, there are many techniques and ways to awaken the Kundalini that are given in the shastras. For instance, there is what is known as the ‘Sri Vidya Upasana’ that the followers of Samaya Marga use to awaken the Kundalini energy.