Acoustic Resonance Therapy (A.R.T.) from SO Sound® combines the healing effects of sound and vibration to harmonize all systems of the body bringing you to a deeper state of relaxation. Attached at specific locations in the sauna, the SO Sound® system uses an amplified audio signal to resonate sound waves to the surface of the sauna. Listening to soothing music and feeling it resonate throughout the body stimulates the body’s natural relaxation response. It feels like light touch massage during your sauna session. SO Sound® can be easily installed into any wooden Sunlighten sauna.