This sound healing uses only one of my Crystal Singing Bowls. This journey is focussed on the 432Hz A-note singing bowl. 

There is some evidence to say that the 432 Hz solfeggio frequency is in tune with the Shumann Resonance, and others note that the 432 Hz may be a healing frequency through reducing anxiety and promoting sleep.

Whether there is sufficient evidence for these or not, I hope that you may find the crystal singing bowl journey relaxing.