With the addition of the ‘a’ and ‘h’ sounds, the Mutes become twenty seven and this is the number of the lunar constellations in the Vedic system . Each constellation marks thirteen degrees and twenty minutes of arc in the zodiac.
The Semi–vowels are the Antahsthah for they reflect the inner energies. Their significance in the body Chakra system of Tantrās is that they comprise the bīja mantrā for the lowest four body Chakras viz.’ya’ for the Heart or Anāhat Chakra ; ‘ra’ for the Navel or Maṇipūra Chakra ; ‘va’ for the Genitals or Swādhisthān Chakra ; ‘la’ the lower Pelvic or Mūlādhāra Chakra. The interesting symmetry in these Antahsthah is that their sounds are structured by the reverse combination of ‘a’ with the rest of the four primary svars. This is somewhat like the combination of the nucleotides C, G, A and T in the DNA structure.
We have seen here how an isomorphism from external reality to discursive language has been created. Thus, as we speak the first vowel ‘a’ to the last mute ‘ma’ – the glottis to the labials are traced and the entire mouth is virtually ‘shaped’ in the varṇas or letters. This is the universal ‘aum’.