"We sing the mantra of Padmasambhava in three different ways for differing reasons vis-à-vis their effect on the rTsa rLung system. Four contrasting qualities of sound are used in the singing: hard and soft; loud and quiet; fast and slow; high and low. Once the subtlety of the changes in quality of the sound are mastered, the singing of the mantra becomes a powerful experience and a valuable tool in terms of practising with the different characteristics of our own energy."
Aro Buddhism, Ngala Nor’dzin Pamo