W6: Audition Flashcards
(78 cards)
define
Sounds
audible variations in air pressure
almost anything that can move air molecules can generate sound
state
Audible Frequency Range of Humans
20Hz - 20,000Hz
Frequency of Sound
number of compressed or rarefied patches of air that pass by our ears each second
One Cycle of Sound
the distance between successive compressed patches
Hertz (Hz)
units expressing sound frequency, number of cycles per second
kind of a trick question – so like not a number
At what speed to sound waves propagate?
All sound waves propagate at the same speed!
Pitch
Whether a sound is perceived to have high / low tone, as determined by frequency
higher frequency = higher pitch
lower frequency = lower pitch
Intensity / Amplitude
Property of a sound wave - the difference in pressure between compressed and rarefied patches of air
Sound intensity determines the loudness we perceive (louder sounds having higher intensity)
List
First Stages of the Basic Auditory Pathway
Pinna -> Ear Canal -> Tymp. Memb. -> Ossicles -> Oval Window -> Cochlea
- Sound waves move the tumpanic membrane (bubinek)
- Ossicles (maleus, incus, stapes) move the membrane (footplate) at the oval window
- Motion at the oval window moves the fluid in the cochlea
- Movement of the fluid in the cochlea causes a response in sensory neurons (hair cells -> spiral ganglion)
define
Pinna
helps collect sounds from a wide area, its convolutions playing a role in localising sounds
define
Ear / Auditory Canal
entrance to the internal ear, extending ca. 2.5cm inside the skull before ending at the tympanic membrane
define
Ossicles
Maleus, Incus, Stapes
Series of bones connected to the medial surface of the tympanic membrane.
Smallest bones of the body
latin for “little bones”
define
Oval Window
Hole in the bone of the skull (covered by the footplate of the stapes)
define
Cochlea
Spiral cavity of the inner ear (fluid-filled) behind the oval window, containing the apparatus for transforming the physical motion of the oval window into a neural response (TRANSDUCTION)
MGN
Medial Geniculate Nucleus
list
Components of the Middle Ear (3)
- ONE tympanic membrane
- TWO tiny muscles attaching to ossicles
- THREE ossicles
Eustachian Tube
Ossicle 1
Maleus (hammer)
attached to tympanic membrane
Ossicle 2
Incus (anvil)
Ossicle 3
Stapes (stirrup)
its movements transmit sound vibrations to cochlea fluids
state
Role of Ossicles
sound force amplification
the fluid in the inner ear resists being moved much more than air does do more pressure is needed to vibrate the fluid than air can provide. The ossicles provide this necessary amplification in pressure
because
Pressure = force exerted / SA
state
Two Muscles Attached to the Ossicles
- Tensory Tympanu Muscle
- Stapedius Muscle
define
Sound Attenuation
Response to the onset of a loud sound that triggers a neural response that causes these muscles to contract. When these muscles contract, the chain of ossicles becomes more rigid, and sound conduction to the inner ear is greatly diminished. Sound attenuations is much greater at low frequencies than at high frequencies.
role of cohclea - state
Cochlea
Plays role in transforming sound into a neural signal