The study, part of an overarching project called Body Score, evaluated the heart rhythms of 15 18-year-old high school students as they hummed, sang a Swedish hymn and chanted a slow mantra.
“Singing regulates activity in the so-called vagus nerve which is involved in our emotional life and our communication with others and which, for example, affects our vocal timbre. Songs with long phrases achieve the same effect as breathing exercises in yoga. In other words, through song we can exercise a certain control over mental states,” Björn Vickhoff, the study’s lead author, said in a statement.
The researchers are unsure exactly why the synchronized heart rhythms occur, but speculate it is because of the regular breathing pattern that comes with singing in unison. As a result, they also hypothesize this could have health benefits, which they ultimately hope will lead to more understanding of how music could be used in medical rehabilitation and preventative care.
“In the case of controlled breathing, the heart rate or pulse decreases when breathing out during exhalation in order to then increase again when breathing in during inhalation. This is due to breathing out exhalation activates the vagus nerve that lowers the heart rate which slows down the heart. The medical term for this fluctuation in heart rate the connection between breathing and heart rate is RSA and it is more pronounced with young people in good physical condition and not subject to stress. Our hypothesis is that song is a form of regular, controlled breathing, since breathing out exhaling occurs on the song phrases and breathing in inhaling between these,” Vickhoff said.
“We already know that choral singing synchronizes the singers’ muscular movements and neural activities in large parts of the body. Now we also know that this applies to the heart, to a large extent.”