This special sound is used in many Silva Mental Exercises. Play it while meditating with the Silva techniques or simply to drift off to sleep.
The Theta to Delta sound consists of two similar sounds. The Theta sound ticks at 5 beats per second whereas the Delta sound ticks at between 0-4 beats per second. It is used to help your brain frequency slow down towards a passive, deep and calm inner state associated with the theta frequency. At theta, the thinking is inductive. At this deep inner state old memories and experiences can be triggered as well as intuitive impressions and hypnagogic dreams.
Theta meditations are very deep and can result in sleep. . The shift from 5 ticks per second to 1 ticks per second helps the brain frequency go even deeper allowing for easy entry to a sleeping state.