Module 4.3 - The Auditory System Flashcards
what pushes air molecules together and apart in waves?
objects vibrating pushes air molecules together and apart in waves
what are the 2 functions of the human ear
1) to detect sound waves (sensation)
2) transform that information into neural signals (leading to perception)
frequency
a measure of wavelength reflecting the number of cycles a sound wave travels per second
what is frequency measured in?
Hertz (Hz)
pitch
the perceptual experience of sound wave frequencies
true or false: humans detect sounds from 20 - 20,000 Hz
True
amplitude
an element of a sound wave that determines its loudness
whats louder: high amplitude sound waves or low amplitude sound waves?
high amplitude sound waves are louder than low amplitude sound waves
what is loudness measured in?
Decibels (dB)
Timbre
the complexity of the sound. most natural sounds are complex, consisting of several different frequencies of vibration
what causes the basilar membrane to flex?
vibrations
what happens when the basilar membrane flexes?
it displaces fluid, which causes cilia to move. This movement stimulates auditory nerve fibers
cilia
hair like cells
true or false: cilia is arranged in rows from tallest to shortest
FALSE: cilia is arranged in rows from shortest to tallest
tip links
elastic filaments connecting groups of cilia in the cochlea
true or false: tip links are normally slightly stretched
true
does moving the bundle of cilia towards the tallest one increase or decrease the rate of firing
moving the bundle of cilia towards the tallest one increases the rate of firing
does moving the bundle of cilia towards the shortest one increase of decrease the rate of firing?
moving the bundle of cilia towards the shortest one decreases the rate of firing
what 3 places does the auditory nerve project to?
1) brainstem nuclei
2) the medial geniculate nucleus of the thalamus
3) the primary and secondary auditory corticles
sound localization
the process of identifying where sound comes from; it is handled by parts of the brainstem and the inferior colliculus
sound can be localized by means of? (3 things)
1) arrival time differences between ears
2) phase differences between ears
3) intensity differences between ears
sound shadow
intensity differences between ears
volley principle
groups of neurons fire in an alternating fashion, thus allowing the frequencies higher than 1000Hz (the max vibration rate of the basilar membrane) to be perceived
do loud stimuli or quiet stimuli cause the tympanic membrane to vibrate more?
very loud stimuli
true or false: a higher rate of neural firing is associated with a louder stimuli
true
primary auditory cortex
a major perceptual centre of the brain involved in perceiving what we hear
tonotopic organization
different areas of the auditory cortex respond to different frequencies
secondary auditory cortex
a temporal lobe region that helps us to interpret complex sounds, including those found in speech and music
is the right or left hemisphere slightly more sensitive?
the right hemisphere is slightly more sensitive
________ are involved in the detection of musical beats
basal ganglia
patients with _____ damage could not tell that musical pieces were scary
amygdala damage
what musical impairments are there with parkinsons disease?
detection of musical beats
what are the 3 functions of the vestibular system?
1) maintaining balance
2) maintaining the head in an upright position
3) adjusting eye movements to compensate for head movements
vestibular sacs/otolith organs
structures that respond to the force gravity and that provide information about the heads orientation
semicircular canals
structures that respond to angular acceleration (changes in the rotation of the head)
3 canals detect acceleration in different directions which are:
up-down, left-right, forward-backward
