Shiva Shakti

1. In the middle of ATHMA--PRANA is there
2. In the middle of PRANA--DHVANI(SOUND) is there
3. In the middle of DHVANI--NADA(sound vibration) is there
4. In the middle of NADA ----SADASHIVA(GOD) is there

http://aumshiva.blogspot.in/
http://www.yogavision.in/articles/30552bd2-7eda-40ec-8b2a-c1c97a5221e9.aspx