The Ear, Hearing, and Pain

Amplitude

Height of the wave; determines loudness (decibels)

Frequency

Length of the waves; determines pitch (measured in megahertz)

Auditory Canal

Ear canal carrying sound to the tympanic membrane

Pinna

Outer ear where sound waves are first collected

Tympanic Membrane

Thin membrane that vibrates when sound hits it

Malleus

Inner‑ear bone shaped like a hammer; vibrates and connects to the anvil

Incus (Anvil)

Inner‑ear bone connected to the stirrup; vibrates due to sound

Cochlea

Snail‑shaped, fluid‑filled structure reacting to vibrations

Organ of Corti

Neurons activated by movement of hair cells on the basilar membrane

Place Theory

Different hair cells respond to different frequencies based on location

Frequency Theory

Lower tones sensed by the rate at which hair cells fire

Conduction Deafness

Problem conducting sound to the cochlea

Sensorineural Deafness

Hair cells in the cochlea are damaged (often from loud noise)

Gate-Control Theory

Some pain messages have higher priority than others