A binocular cue for perceiving depth. By comparing retinal images from the tow eyes, the brain computes distance--the greater the disparity (difference) between the two images, the closer the object.

A depth cue, such as retinal disparity, that depends on the use of two eyes.

A laboratory device for testing depth perception in infants and young animals.

The ability to adjust to changed sensory input, including and artificially displaced or even inverted visual field.

Perceiving Familiar objects as having consistent color, even if changing illumination alters the wavelengths reflected by the object.

Perceiving objects as unchanging (having consistent color, brightness, shape, and size) even as illumination and retinal images change.

An illusion of movement created when two or more adjacent lights blink on and off in quick succession.

The chamber between the eardrum and cochlea containing three tiny bones (hammer, anvil, and stirrup) that concentrate the vibrations or the eardrum on the cochlea's oval window.

A tone's experienced highness or lowness; depends on frequency.

The number of complete wavelengths that pass a point in a given time (for example, per second).

The sense or act of hearing.

A less common form of hearing loss, caused by damage to the mechanical system that conducts sound waves to the cochlea.

Hearing loss caused by damage to the cochlea's receptor cells or to the auditory nerves; the most common form of hearing loss, also called nerve deafness.

The innermost part of the ear, containing the cochlea, semicircular canals, and vestibular sacs.

A coiled, bony fluid-filled tube in the inner ear; sound waves traveling through the cochlear fluid trigger nerve impulses.

The theory that the spinal cord contains a neurological "gate" is opened by the activity of pain signals traveling up small nerve fibers and is closed by activity in larger fibers or by information coming from the brain.

In hearing, the theory that the rate of nerve impulses traveling up the auditory nerve matches the frequency of a tone, thus enabling us to sense its pitch (also called temporal theory).

In hearing, the theory that links the pitch we hear with the place where the cochlea's membrane is stimulated.

A device for converting sounds into electrical signals and stimulating the auditory nerve through electrodes threaded into the cochlea.