As a practitioner of Biofield Tuning which uses tuning forks around the body and I am also trained in crystal singing bowls, I can say personally and as a practitioner I have both had and seen amazing results with sound. Positive results both physical and emotional. Coherent sound produced by instruments such as these help entrain your body into a more coherent state. It can do this because everything is vibration. Your organs, your cells, your bones, etc. all have a natural frequency. When that frequency is out of its normal range or in discord then dis-ease can set in. Bringing it back to coherence by using an instrument that produces a coherent sound brings your body back to its factory settings. Back into balance.