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

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.