528 Hz - Theta

Frequency of 528 Hz also reduces total concentration of reactive oxidative species in brain tissue. Prolonged exposure to this sound wave showed reduction of anxiety related behaviors in rats. The results reveal that reduced anxiety is related to increased concentration of testosterone in brain.

https://higherfrequencies2.bandcamp.com/
Theta 4 - 8 Hz - Rem sleep, Deep relaxation and inner pace, Meditation, Enhanced creativity, Dreamlike states.