Nitric oxide is known to be increased 15- to 20-fold by humming. Nitric oxide is a naturally produced molecule that plays a crucial role in blood vessel dilation, improving blood flow, and supporting overall cardiovascular health.

This is also why Monks hum, chant, or use specific sounds like "Om" or "Aum" during meditation or prayer to focus their minds, create a calming atmosphere and induce a meditative state.