To clarify the this Heart chakra topic:
The Confusion And Corruption Of Eastern Teachings
https://www.ancient-forums.com/viewtopic.php?f=24&t=17673&p=66112&hilit=Yaum#p66112
The heart chakra is called Anahata which means the "Unstruck Sound" and the deity shown in this chakra traditionally represents the element of ether. Unstruck Sound in Hinduism is from what the knowledgeable swami's will tell you means the sound AUM. The heart chakra is ruled by ether and its bija mantra is AUM.
The AUM mantra the heart rules the flow of power upwards into the brain and upper chakra's and energy field. By switching this it weakens the flow of energy into the upper chakra's and the Aura and thought the chakra's. The Yaum by being moved into the heart removes the sound needed for the ignition of the chakra's of the third eye and opening the crown and by removing the crown mantra finishes this. This works to close one off from opening the chakra's in the head which rule the psychic functions and higher communication and knowledge abilities such as gnosis. And retards the progress of the Amirta to regenerate the body and activate the chakra's and nadi's for kundalini ascension.
The vibration for 4th and 6th Chakra vibrations has been changed.
https://www.ancient-forums.com/viewtopic.php?f=3&t=12433&p=43569&hilit=Yaum#p43569
The heart chakra is ruled by mercury which rules the element of spirit which is AUM. The sixth chakra is called Ajna…..Jana means wisdom the Goddess of wisdom....Jana is also Yana....Yaum.
Yaum has always been the moon chakra and Aum the heart however this was corrupted by the enemy and Azazel showed us the true way its used.
https://www.ancient-forums.com/viewtopic.php?f=3&t=3023&p=52215&hilit=Yaum#p52215
Note Ajna…… Jana which is Yana.....Yaum this is the Jana Pandita the Lord of Wisdom. In Kriya yoga the Aum is placed in the heart chakra.
My note: YAUM is the root sound of Yama, which means control. The sanskrit name for the 6th Chakra is Ajna, which means “Command Center” The 6th has to power to control and regukate the other chakras the same way the pituitary gland regulates the other endocrine glands.
To sum it up:
-the mantra YAUM is specific for and should be vibrated into the 6th, aka the Ajna aka “the Heart”
-the mantra AUM should be vibrated into the 4th, aka Anahata, aka “the Heart Chakra”