The voice of the silence is intuition. It is knowing without the interference of the intellect. The language of intuition is the language of the consciousness and God, which can only come as a result of ethical discipline (Yama and Niyama), posture (Asana), silence of mind (Pratyahara), concentration (Dharana), meditation (Dhyana) and ecstasy or comprehension (Samadhi).

This is well modeled in the Gnostic Meditation Course, which we recommend you study if you are not familiar with it. Without knowing the methods for developing intuition and experiencing the voice of the silence, one can achieve no genuine progress.