U — crown resonance
Sahasrāra-region vowel
U is shown rising towards the crown as the sustaining middle movement of AUM. Crown placement is a comparative subtle-body convention and varies among mantra and chakra lineages.
Point 7 of 8 in Nāda Yoga — Sound-Body Resonance Map
Cross-tradition overlaps
- U — crown resonance ↔ Crown (distance 0.005)
Sources
Yoga Sūtras 1.27–29 (primary_canonical)
Praṇava contemplation is the textual basis for the AUM sequence.
Guy L. Beck, Sonic Theology: Hinduism and Sacred Sound (scholarly_modern)
Discusses transcendent and cranial readings of sacred sound.