Concept:
- Reversing the hearing process: activating hair cells instead of sound waves entering the ear.
- When outer hair cells are stimulated (hypothetically by a zap), they contract/elongate, causing a pressure wave.
Pressure Wave Movement:
- This wave travels backward through the cochlea, middle ear ossicles, and eardrum.
- A faint sound wave exits the ear canal (inaudible to humans).
Detection and Applications:
- Detectable by a microphone in the ear canal and called otoacoustic emissions (OAEs).
- Used as a diagnostic tool to assess inner ear health, especially in infants and non-verbal individuals.
- OAE presence indicates a functioning cochlear amplifier.
Next Steps:
- The lecture will explore the link between OAEs and hearing loss.