I was sitting by a window some foggy late morning in Japan, listening to the birds outside, their song experienced as a movement of Consciousness, my body as wide as the whole world. So internal and familiar was the birdsong, that their language seemed to be translating into English. And it goes just the same for every kind of perception. The birds are singing inside of you! To go through a whole life thinking oneself as a tension in the head with an attached biography is a small life compared to our full perceptual potential. The whole world is happening within your own vast consciousness, and your consciousness is as vast as the universe!
We all have glimpses of this, but it becomes a more permanent fixture of our experiential range the more our nervous system relaxes into Silence. And, if one becomes quiet enough, the sound of Om can lead one all the way back home to the primordial unity of the un-struck dawn.
How to access this place on nondual unity? While one doesn’t need any tool to experience what is already their own consciousness, in practical terms a good tool is extremely valuable. The Ishayas’ Ascension practice is the most effective I’ve personally encountered, though there are several others in the same ballpark, and different meditations will be more or less resonant for different people. Whatever tool one finds particularly useful, the key is to use it with consistency and dedication in order to enjoy the maximum harvest of its benefits. Go for it!