7.1 Audition Flashcards
When a tree falls, the tree and the ground ____, setting up sound waves in the air that strike the ears.
vibrate
____ ____ are periodic compressions of air, water, or other media.
Sound waves
Sound waves ____ in amplitude and frequency.
vary
The ____ of a sound wave is its intensity. A bolt of lightning produces a sound wave of great amplitude.
amplitude
____ is a sensation related to amplitude but not identical to it.
Loudness
The ____ of a sounds the number of compressions per second, measured in Hz. ____ is the related aspect of perception. Higher frequency sounds are higher in pitch.
frequency : Pitch
Most adult humans hear sounds ranging from about __Hz to somewhat less than ____Hz.
15 - 20,000
Children hear higher frequencies than adults, because the ability to perceive high frequencies ____ with age and exposure to loud noises.
decreases
Anatomists distinguish the ____ ear, the ____ ear, and the ____ ear.
outer : middle : inner
The outer ear includes the ____, the familiar structure of flesh and cartilage attached to each side of the head. By altering the reflections of sound waves, the ____ helps us locate the source of sound.
pinna
After sound waves pass through the ____ ____, they strike the tympanic membrane, or eardrum, in the middle ear.
auditory canal
The ____ ____ vibrates at the same frequency as the sound waves that strike it.
tympanic membrane
The tympanic membrane connects to 3 tiny bones that transmit the vibrations to the ____ ____, a membrane of the inner ear.
oval window
These bones of the middle ear are sometimes known by their English names (____, ____, and ____) and sometimes by their Latin names (malleus, incus, and stapes).
hammer, anvil, and stirrup
The tympanic membrane is about ____ times larger than the footplate of the stirrup, which connects to the oval window.
20
The ____ of the tympanic membrane transform into more forceful ____ of the smaller stirrup.
vibrations
The net effect converts the sound waves into waves of greater ____ on the small oval window. This transformation is important because more force is required to move the viscous fluid behind the oval window than to move the eardrum, which has air on both sides.
pressure
The inner ear contains a snail-shaped structure called the ____. Cochlea has three long fluid filled tunnels: the scala vestibuli, scala media, and scala tympani.
cochlea
The stirrup makes the oval window vibrate at the entrance to the ____ ____, thereby sitting in motion the fluid in the cochlea.
scala vestibuli
The auditory receptors, known as ____ ____, lie between the basilar membrane of the cochlea on one side and the tectorial membrane on the other.
hair cells
Vibrations in the fluid of the cochlea displace the hair cells. A hair cell responds by opening ___ ____ in its membrane.
ion channels
