In Sweden, they studied the heart rates of choir members as they sang together. The findings, published in Frontiers in Neuroscience, confirmed that this experience had calming effects on the heart — especially when singing in unison. Using pulse monitors attached to the singers' ears, researchers measured changes in the members' heart rates as they sang. They noticed their heart rates slowed down. When you exhale, the heart does slow down but what was really interesting was that it took almost no time for hearts to begin merging toward a shared rhythm.
- Dharma Center of Oklahoma Newsletter