Term | Definition |
absorption | the taking in of a wave's energy |
amplitude | the distance from the midpoint of a wave to a crest or a trough |
compression | a part of a longitudinal wave where the particles get pushed closer together |
crest | the highest point of a transverse wave |
frequency | the number of waves that pass a point in a given amount of time |
inner ear | the part of the ear that transmits information about vibrations to the brain (cochlea, semi-circular canals) |
compressional/longitudinal wave | a wave in which the particles of the medium vibrate parallel to the path of the wave |
mechanical wave | a wave that requires a medium |
medium | a material through which mechanical waves can travel through |
middle ear | the part of the ear that transfers vibrations from the outer ear to the inner ear (hammer, anvil, stirrup) |
outer ear | the part of the ear that gathers sound vibrations (pinna, outer ear canal, eardrum) |
rarefaction | the part of a longitudinal wave where the particles are spread apart |
transverse wave | a wave in which the particles of the medium vibrate in a direction perpendicular to the path of the wave |
trough | the lowest point of a transverse wave |
vibration | a repeated back-and-forth motion |
wave | a disturbance that transfers energy through matter and space |
wavelength | the distance from any point on a wave to the identical point on the next wave |
wave speed | the distance a wave travels per unit of time |
electromagnetic waves | a disturbance that can transfer energy through a vacuum or through matter |
reflection | the bouncing back of waves when they strike the surface of a new medium |
color filter | a piece of transparent material, such as colored glass, that absorbs some frequencies of light and transmits others |
convex lens | a lens that is thicker in the middle than it is at the edges |
cornea | the transparent layer that makes up the front of the eye |
diffraction grating | a device that separates white light into colors by means of many narrow slits |
electromagnetic spectrum | the range of all frequencies of electromagnetic waves |
infrared radiation | electromagnetic waves with frequencies below those of visible red light |
lens | the part of the eye that focuses light |
opaque | allowing no light waves to be transmitted |
optic nerve | the nerve that carries information from the retina to the brain |
plane mirror | a flat, smooth surface that can reflect light and produce a clear image |
prism | a transparent object that separates white light into the different colors that make up white light |
refraction | the bending of waves caused by a change in their speed as the pass from one medium to another |
retina | a light-sensitive layer at the back of the eye |
translucent | transmitting some light but scattering it |
transmission | the passing of waves through a medium |
transparent | transmitting most light waves; clear |
ultraviolet radiation | electromagnetic waves with frequencies higher than those of visible violet light |
visible light | electromagnetic waves that can be detected by the human eye |
visible light spectrum | the full range of electromagnetic waves that can be detected by the human eye |
anvil | (also called the incus) a tiny bone in the middle ear that passes vibrations from the hammer to the stirrup |
cochlea | a spiral-shaped, fluid-filled inner ear structure; it is line with cilia (tiny hairs) that move when vibrated and cause a nerve impulse to form |
eardrum | (also called the tympanic membrane) a thin membrane that vibrates when sound waves reach it |
echoes | reflections of sound waves |
Eustachian tube | a tube that connects the middle ear to the back on the nose; equalizes the pressure between the middle ear and the air outside. When you "pop" your ears as you change altitude, you are equalizing the air pressure in your middle ear. |
hammer | (also called the malleus) a tiny bone in the middle ear that passes vibrations from the eardrum to the anvil |
nerves | these carry electro-chemical signals from the inner ear (the cochlea) to the brain |
outer ear canal | the tube through which sound travels to the eardrum |
semicircular canals | three loops of fluid-filled tubes that are attached to the cochlea in the inner ear; helps us maintain our sense of balance |
stirrup | (also called the stapes) a tiny, U-shaped bone in the middle ear that passes vibrations to the cochlea--smallest bone in the human body (it is 0.25 to 0.33 cm long) |