Srimad-Bhagavatam: Canto 11 - Chapter 14 - Verse 34
Srimad-Bhagavatam: Canto 11 - Chapter 1 - Verse 34 Sanskrit: हृद्यविच्छिन्नमोङ्कारं घण्टानादं बिसोर्णवत् ।प्राणेनोदीर्य तत्राथ पुन: संवेशयेत् स्वरम् ॥ ३४ ॥ ITRANS: hṛdy avicchinam oṁkāraṁghaṇṭā-nādaṁ bisorṇa-vatprāṇenodīrya tatrāthapunaḥ saṁveśayet svaram Translation: Beginning from the mūlādhāra-cakra, one should move the life air continuously upward like the fibers in the lotus stalk until one reaches the heart, where the sacred syllable om is situated like the sound of a bell. One should thus continue raising the sacred syllable upward the distance of twelve aṅgulas, and there the oṁkāra should be joined together with the fifteen vibrations produced with anusvāra....