In yoga it is called Brahmari Breath or the Breath of the Bumble Bee but not only the yogis think it is useful. Patrick McKeown, James Nestor and even Wim Hof found out that humming and audible exhales can help our breath to slow down and find back into a normal, healthier breathing pattern.
Humming increases the release of nitric oxide in the nasal passages 15-fold. There is the most effective, and simple, method for increasing this essential gas.
It may sound ridiculous, and feel ridiculous, and annoy those nearby, but the effects can be potent.