In a cave, all outer sounds are smothered by rock and earth, but this makes the sounds of one's own heartbeat and breath audible. In the same way, contemplative stillness turns us away from everyday clamor but allows us to hear the subtle in our own lives.

When listening not with the ear but with the spirit, one can perceive the subtle sound. By entering into that sound, we enter into supreme purity. That is why so many religious traditions pray, sing, or chant as a prelude to silence. They understand that the repetition and absorption of sound leads to sacredness itself.

The deepest sound is silence. This may seem paradoxical only if we regard silence as an absence of life and vibration. But for a meditator, silence is sound unified with all of its opposites. It is both sound and soundlessness, and it is in this confluence that the power of meditation emerges.