Schumann Resonance is said to be the earth resonance. It is entrainment at 7.8 hz.
Studies of the most advanced meditators have repeatedly shown 7.8 to be a significant frequency (M. Cade).

• It is said to stimulate the release of growth hormones (N. Shealy). 
• It is also referred to as the Hypnagogic (the mental state of an someone who is on the brink of sleep) state. 
• More spiritual experiences have been reported using this frequency than any other. 
• Out of body experiences have also been reported.