the Five Aggregates (Pañcakkhandha) process at the Ear Door (Sotadvāra):

1. When sound (sadda) strikes ear-sensitivity (sota-pasāda):
- Sound = Rūpakkhandha
- Ear-sensitivity = Rūpakkhandha

2. Hearing-consciousness (sota-viññāṇa) arises with:
- Feeling (vedanā)
- Perception (saññā)
- Mental formations (saṅkhāra), primarily cetanā (volition)
- Consciousness (viññāṇa)

These four mental factors (nāmakkhandha) always arise together - they cannot arise separately according to Abhidhamma principles.

3. Complete process includes:
- 4 Mental aggregates (nāmakkhandha)
- 1 Material aggregate (rūpakkhandha)
= Five Aggregates (pañcakkhandha)

Key References:
- MN 43 Mahāvedalla Sutta
- Abhidhammatthasaṅgaha, Chapter 3
- Visuddhimagga XIV, 81-82

This process demonstrates:
- Interdependence of mind and matter
- Momentary nature of experience
- How consciousness requires supporting mental factors