Vishuddha Chakra:
Vishuddha Chakra is situated within the Sushumna Nadi at the base of the throat, Kantha-Mula Sthana. This corresponds to Janar Loka. It is the centre of Akasa Tattva (ether element). The Tattva is of pure blue colour. Above this, all other Chakras belong to Manas Tattva. The presiding deity is Sadasiva (Isvara Linga), and the Goddess is Shakini. From this centre emanate 16 Yoga Nadis which appear like the petals of a lotus.
The vibrations that are produced by the Nadis are represented by the 16 Sanskrit vowels:—Aö A:ö Eö Iö uö Uö ?ö @ö ;ö =ö Oö Oðö A:ðö A:òö Aö AH (aü àü iü ãü uü åü çü éü ëü íü eü aiü oü auü aü and aþ). Akasa Mandal (the region of ether) is round in shape like the fullmoon. The Bija of Akasa Tattva hö (haü) is in this centre. It is of white colour. This Chakra corresponds to Laryngeal plexus in the physical body.
The concentration on the Tattva of this Chakra is called Akasa Dharana. He who practises this Dharana will not perish even in Pralaya. He attains the highest success. He gets the full knowledge of the four Vedas by meditating on this Chakra. He becomes a Trikala Jnani (who knows the past, the present and the future).