I had discovered this “inner sound” many years before but had never heard or read any reference to this in the Pali Canon. I had developed a meditation practice referring to this background vibration and experienced great benefits in developing mindfulness while letting go of any thoughts. It allowed a perspective of transcendent awareness where one could reflect on the mental states that arise and cease in consciousness.
‘Nada Yoga’ (meditation on the inner sound) is a practice that is known in Vedic, Buddhist and other traditions to be a powerful and liberating spiritual discipline and is also one that I have used for over twenty-five years, to great benefit. »
Ajahn Sumedho’s disciple, abbott of Amaravati monastery in the Forest lineage of the Theravada Buddhist tradition
The seeker requires concentration aids. Bodily sensation and attention to breathing comprise two excellent methods of returning to oneself in a continual now. In addition to these two aids, there is a particularly effective one to reduce inner chatter: it is the inner sound, the Nada as it is called in India, which can be heard inside the ears and head.