You stimulate the cerebral cortex which in turn calms down the hypothalamus and even pain receptors. This may explain why people scream or yell when they get hurt!
Making a single tone stimulates the vagus nerve. The vagus nerve is the longest nerve of the human autonomic nervous system. It's fibers connect to all of your body's organs from the neck down (except the adrenal glands), making it the primary component of your parasympathetic nervous system. (Vagal nerve function is extremely important for healthy digestion!)
When you make the sound of AUM, your brainwaves produce more alpha and theta waves, and this is the state hypnotherapists like to get their subjects into as it is the time when suggestions work best.
Through the power of intention and visualization you can stimulate the creation of new brain cells in the cerebral cortex.
AUM is actually 3 syllables, A-U-M pronounced Ahhh, Ooooh and Mmmmm. Each of these tones creates a vibration in a different area of the body.
Ahhh = Stomach/Abdomen
Ooooh = Heart/Chest/Throat
Mmmm = Brain/Pineal/Pituitary Gland
Through this toning sequence you can vibrate and stimulate the endocrine glands and energy centers of each of these areas of your body.
This has the power to create, restore and revitalize the cells and organs important for your optimal health and longevity.
However it is the higher tones of Mmmm that stimulates your higher cortical functions and glands of the pineal and pituitary.
Let’s practice:
Now take a deep diaphragmatic breath, making sure your abdomen rises as you breath, for a count of 4 seconds.
On your out breath chant the sacred chant Aum with the full syllables focusing on Aaaa, then Ooooo, then Mmmmm – feeling and enhancing the vibrations on each region of your body with your intention.
Now repeat this exercise again for 5-10 minute. Breathe in Chant Aum. Then observe how you feel more relaxed and calm at the end of it.