432 Hz. sound
http://powerthoughtsmeditationclub.com/info-on-432hz-music/
Modern science has begun to recognize what the ancient mystics and wise men have told us for centuries; that everything is in a constant state of vibration. Everything down to the smallest physical particle to the things we cannot perceive with our (yet) limited senses.
The most elemental state of vibration is that of sound. Everything has an optimum range of vibration (frequency), and that rate is called resonance. When we are in resonance, we are balanced. Every organ and every cell in our precious body absorbs and emits sound with particular optimum resonate frequency. 432hz and 528hz tuned music creates resonance in our physical, mental, emotional and spiritual body.