The Ear and Sound Transduction

Vocabulary flashcards covering the anatomy and physiology of the ear, sound wave properties, and the process of auditory transduction based on the lecture notes from 02/13/2026.

Amplitude

The property of a sound wave that determines its volume, loudness, or intensity.

Pitch

The perception of sound determined by the frequency of the wave; it has a positive relationship where pitch gets higher as frequency increases.

Hertz ($Hz$)

The unit of measurement for the frequency of a sound wave.

Pinna

The fleshy exterior part of the outer ear that collects sound.

Ear / Auditory Canal

The passage that connects the pinna to the ear drum.

Tympanic Membrane

Also known as the eardrum, this membrane translates sound strikes into vibrations that pass through the middle ear.

Ossicles

Three bones in the middle ear that connect the tympanic membrane to the oval window and conduct sound vibrations.

Oval Window

The membrane through which sound vibrations from the ossicles enter the inner ear.

Middle Ear Muscles

Two specialized muscles that, when contracted, cause the ossicles to vibrate less and reduce perceived volume.

Cochlea

A snail-shell shaped structure in the inner ear containing a spiral-shaped, fluid-filled space.

Organ of Corti

A spiral-shaped, multi-layered strip of tissue in the cochlea that detects waves and turns them into signals for the nervous system.

Basilar Membrane

A part of the Organ of Corti that ripples and flexes in response to waves; its regions are arranged by frequency from the base (highest) to the apex (lowest).

Hair Cells

The receptors in the Organ of Corti that transduce sound into electrical activity.

Stereocilia

Hair-like structures on hair cells embedded in the tectorial membrane that open mechanically-gated ion channels when deflected.

Tectorial Membrane

A membrane running parallel to the basilar membrane that does not flex in response to sound.

Generator Potential

A potential created by the opening of mechanically-gated ion channels that depolarizes the hair cell.

Glutamate

The neurotransmitter released by hair cells onto Spiral Ganglion neurons when voltage-gated calcium channels open.

Spiral Ganglion Neurons

A cluster of cell bodies following the spiral shape of the cochlea that make up the cochlear part of the vestibulocochlear nerve.

Vestibulocochlear Nerve

The nerve that conducts action potentials from the spiral ganglion neurons into the Central Nervous System (CNS).