अभ्यासादूर्ध्वरन्ध्रेण तालूर्ध्वं द्वादशान्तगे ।प्राणे गलितसंवृत्ते प्राणस्पन्दो निरुद्ध्यते
In plain words
Through practice, by way of the upper aperture, when prāṇa has gone to the dvādaśānta above the palate and has become dissolved there -- the vibration of prāṇa is restrained.