The Sound is independent of the ten Vital Forces (Pranas) 

The Sidhas, Yogis, asked Guru Nanak:

Where is the home of the Shabd, through which is one ferried across the sea of existence? The air is said to be of ten kinds which one of these sustains it?

 Ramkali M1, 944-9

Guru Nanak replied:

The Shabd is inside us. It is invisible; wherever I look, I find It. The air issues from the void. The Shabd is not sustained by anything.

 Ramkali M1, 944-12

The Shabd is within us. It is invisible. Wherever I look, I see It. The air comes from the void, but the Shabd is not sustained by anything. 

Unless we turn inwards and rise beyond Sushmana, the Royal Vein, we cannot hear It. We can contact the Shabd only in the human body.

By purifying the mind one crosses this world. This is done by reflecting on the quintessence of the self. They who serve the Master enjoy peace, and Shabd pervades their inner being.

 Ramkali M1, 908-2

If one searches the township of the body through the Shabd, one gains the nine treasures of Naam.

Ramkali M2, 910-1

The human body is like a radio receiving-set for listening to the Shabd. When we tune in a radio set, we begin to hear a sound. 

Similarly, when the Master, Satguru tunes us inside, we become fit to hear the Divine Music. Then, by regulating this set, we hear various kinds of sound.