2 HONG SAU variations - shambhavi - ajapa japa - what is correct pronunciation

Why a variation can refresh a technique that has become boring, and the basic Hong-Sau method of mentally chanting with the breath. Two variations follow: breathing through the spiritual eye with eyes in Shambhavi Mudra, said to cool the brain via the frontal sinuses, and Ajapa Japa, listening to the breath's own sound as the true pronunciation.