Auditory Transduction and Visual Perception

Vocabulary flashcards covering the anatomical structures and sensory mechanisms of hearing and visual perception.

Auditory transduction

The process by which the ear converts sound waves in the air into electrical impulses that can be interpreted by the brain.

Tympanic membrane

A cone-shaped membrane that vibrates in response to sound and articulates with a chain of three auditory ossicles.

Auditory ossicles

A chain of three bones in the middle ear cavity consisting of the malleus, incus, and stapes.

Anterior malleol ligament

A ligament in the middle ear holding the malleus in place, which is particularly important for establishing the pivotal axis of the ossicles.

Posterior incudal ligament

A ligament in the middle ear cavity that helps hold the incus in place along the pivotal axis.

Paralymph

The fluid filling the bony labyrinth that is displaced by piston-like movements of the stapes footplate.

Round window

A flexible membrane that allows paralymph to be displaced so vibrations can enter the bony labyrinth.

Scala vestibuli

The portion of the spiral passage in the cochlea in which sound vibrations ascend to the apex.

Scala tympani

The descending portion of the spiral passage within the cochlea.

Cochlear duct

A structure situated between the scala vestibuli and scala tympani filled with endolymph.

Reissner's membrane

One of the flexible membranes visible in cross section that separates fluid-filled systems in the cochlea.

Basilar membrane

A flexible membrane supporting the organ of Corti that vibrates variably at specific locations in response to different sound frequencies.

Organ of Corti

A specialized structure situated on the basilar membrane that sends nerve impulses to the brain via the cochlear nerve when stimulated.

Hair cells

Specialized cells in the organ of Corti with hair clusters that trigger nerve firing when bent against the tectorial membrane.

Tectorial membrane

A structure closely covering hair cells against which hair clusters bend when the basilar membrane vibrates.

Tonotopic organization

The structural arrangement where lower sound frequencies vibrate the basilar membrane closer to the apex and higher frequencies vibrate closer to the base.

Consonance

A quality of musical frequency combinations that people generally find pleasant.

Dissonance

A quality of musical frequency combinations that people generally find unpleasant, irritating, or uncomfortable.

Digital audio converter (DAC)

A device required in digital audio processing to extrapolate missing waveforms between stored bit data points and convert them for speakers.

Tom Moulton

The individual credited with inventing the 12-inch single record format, which allowed for deeper, heavier bass response in dance music.

Cornea

The clear external tissue layer of the eye that helps focus incoming light.

Iris

The colored muscular structure behind the cornea that defines eye color.

Pupil

The black opening in the center of the iris through which light passes into the interior of the eye.

Lens

The flexible structure located behind the pupil that focuses light onto the retina.

Retina

A membrane on the rear interior of the eye containing millions of receptor cells that convert light into electrical signals.

Rods

Photoreceptors (approximately $1.2 \times 10^8$ per eyeball) responsible for black-and-white vision, low acuity, and high sensitivity in dim light.

Cones

Photoreceptors (approximately $6.0 \times 10^6$ per eyeball) located mostly in the fovea responsible for color vision and high acuity in bright light.

Fovea

The central focal region of the retina densely populated with cones.

Acuity

The visual clarity or precision of detailed vision.

Rhodopsin

A photopigment molecule in rods that undergoes a three-dimensional shape change when struck by light, opening sodium channels.

Receptor potential

A graded electrical potential generated across sensory receptor cell membranes during transduction.

Subtractive color mixing

Color mixing that occurs when combining physical pigments, dyes, or paints that absorb specific wavelengths and reflect others.

Additive color mixture

Color mixing that occurs when combining different light wavelengths directly, where combining all spectrum lights produces white light.

Three primary law

The law stating that every color can be created by mixing varying intensities of three correctly chosen unique wavelengths of light.

Law of complementarity

The principle stating that for any single wavelength of light, there exists another single wavelength that combines with it to be perceived as white.