Our body has several tissues and muscles, and all of them have varying shapes and sizes, which also means there is a definite start and end, which is paramount to form shape, this disparity in the external and internal presentation/ behaviour of the body instigated observant people (commonly known as sages) to plunge to “know” why? With the available research, known as “yog”, Sanskrit word meaning "sum" in English, as one organ can’t work in solitary/ standalone mode, its fed by some other organ and it feeds another organ after processing) it was realised these muscles and organ contract and elongate themselves while performing their part of act, and during this process of elongating and contracting, they pass energy (as you would be well aware energy has at least two components, positive and negative terminals and there has to be a potential difference amongst them in order for it to flow, thus producing sound(s), it is this very sound which is observed by the brain which then acts to stimulate/activate the next...these are the sounds upon which meditation is taught.
In the procedure of activating these cosmic and ionic energies, by following strict rules and regimes for decades, as how these 114 points, which are within the body & circumventing energies, These energies are 33 in number by their behaviour, what they do and what all they control, and how they are interlinked. In deep state of Sadhana it can been experienced how Naad Yoga techniques can be used to refine these energies, leading which the life gets transformed for better, there are huge possibilities in each and everyone and the limits are just as conceptions of the person.
The analysis of these invisible but yet life defining energies, these energies are responsible for how life shapes for you, how you think &what you think is also defined by these energies, how people behave with you and you reciprocate to them also how these energies are within you, your love and relationships are it is also because of these energies. A psychic, is the one who decodes these invisible prevailing energies and then analyse how these energies can and should be refined to make the life better for its client.
It's the imbalancing of these energies which is the root cause of each and every issue, may it be sickness or things are just not happening in someone's life. By using the sound of cosmic energies, which are also referred as the sound of silence (because they resonate at higher frequencies so aren't audible to ears, that's why the name sound of silence) healing is done.