At some level, all life is vibration, and sound is a product of vibration. Some sounds have the ability to heal, something that has been known and practiced as far back as 6th century China (as part of Oriental Medicine) and is still used today in Hindu and Buddhist temples throughout the world.
The vibrations that produce sound cause a resonance in the cells of the body which moves energy and fluid and removes blockages. In addition, hearing sound activates the vagus nerve, stimulating the parasympathetic nervous system (sometimes called the "resting and digesting nervous system.") This increased parasympathetic activity improves functioning of the heart, lungs, and other organs, facilitates deeper, slower breathing, and improves integration between the right and left hemispheres of the brain.
The Healing Vibration of Sound
by Avtar Puran and Nishtha Jane Kappy