Surat Shabd Yoga

My question (which requires a little background info to set up) concerns a meditative practice involving listening to the “inner sound, “and how this concentrative practice contrasts/relates with the
practice of a silent mantra meditation. I began meditating in 20000, and after practicing this sporadically, learned a practice known as Surat Shabd Yoga, which involves listening to the inner sound (variously known as Nada, or Shabd, Cosmic Hum, etc.)
I believe someone wrote to you on this forum in the past about hearing inner sounds, and you referred to this as the Cosmic Hum, and that it might be best for the writer not to become too attached to this sound. For the most part, this made sense to me.
But I learned this inner sound practice not simply by coming across it during meditation, as a side effect, but as an actual concentrative practice within the context of the Surat Shabd Yoga tradition. I believe that you have some familiarity with this tradition, as you once wrote a forward in one of Rajinder Singh’s books…
The practice involves closing your ears with ear plugs, and listening to an internal sound, from the right side of the head. A high pitched, humming sound. This practice did bring me great peace at times, and if you listen to the sound long enough, it can become very strong- it definitely has an ethereal quality to it, and can often really slow the flow of thoughts. The idea is that eventually, listening to this sound will charm your mind, take you higher and higher, through various planes of existence (astral, causal, etc) and eventually allow you slip into the ultimate.

But does it lead directly to pure awareness, or pure consciousness? Because listening to this sound involves concentration, my impression is that the mind remains on the surface, at least at the beginning, whereas with mantra meditation, the “dive” into consciousness is relatively quick. But I can’t say for sure whether this is an authentic impression of my own, or if I am only parroting things I’ve read.

Perhaps I’m creating divisions where there are none. But this has been a source of confusion for me, and as I have limited time, I cannot practice everything. And because I go round and round in my mind with this, the sense of confusion often inhibits whatever inner peace I might have otherwise gotten from my practice. Some people have told me that this practice of listening to the Nada is a much more “powerful” practice than mantra meditation, others have said the opposite, that the mantra takes you right away to pure consciousness, which is really what you’re aiming for. I don’t know what to think.
At this point, I happen to be practicing mantra meditation again, often with good results, but these questions always linger.

So, to be more concise, my question is: in your long, wide ranging experience, have you come across this inner sound, and have you come to any conclusions regarding it? Is it a valuable, powerful point of focus in meditation, as many traditions such as Nada Yoga and Surat Shabd Yoga would have,
or is it rather a “symptom” of good meditation? Any thoughts on this — this Nada, or Cosmic Hum–what its value is in spiritual practice, or how it might be received, would be greatly appreciated.