When A Choir Sings Their Hearts Beat As One

Flickr/Dom ArcherA choir doesn't just sing together — when they are performing the groups' heart beats slow and synchronize, a new study found.

The study was published in the journal Frontiers in Neuroscience on July 9. Researchers brought high school choir singers into the lab, and studied their heart rates while they sang a Swedish hymn. When they started singing, their heart beats slowed and synchronized almost immediately.

The rhythm of the beating is guided by the song's tempo, the study authors said.

"When you sing the phrases, it is a form of guided breathing," study researcher Bjorn Vickhoff of the Sahlgrenska Academy, told NPR. "You exhale on the phrases and breathe in between the phrases. When you exhale, the heart slows down."