Why does Sound Meditation Work?

I've been recently going through the meditation playlist and found the sound meditation in particular to be very useful. I also saw the video regarding the effects of meditation on the body and found that very interesting, but it only describes the effects of breathing meditations, as well as why scientists think breathing like that leads to spiritual experiences.

I was curious as to how these questions could apply to sound meditation. What physiological effects does sound meditation have on the body, and why is it that sound meditation caused me to have what i can only describe as being unable to identify any aspect of myself or my body.