Interesting… I will look into that. Part of Wim Hofs teachings include breathing with an extremely long exhale while humming which sounds related. I’ve heard of research showing that any type of breathing with longer exhales than inhales activates a parasympathetic response, calming you down.
Sounds like Indian Om chanting, 3/8th of the duration with 'O' with open mouth and 5/8th with the 'm' hum. There is also a 4 moments inhale, 4 moments hold and 4 moments exhale. We learned it as teens or young adults.
