Audition Flashcards
(117 cards)
0
Q
frequency
A
pitch
1
Q
amplitude
A
loudness
2
Q
complexity
A
timbre
3
Q
sound
A
pressure waves generated by vibrating air molecules
4
Q
timbre
A
characteristics and qualities of a tone apart from simply loudness and its pitch–usually described in qualitative terms
“complexity” of waveforms
5
Q
sound waves propagate in….creating…
A
3 dimensions
spherical “shells”
6
Q
adults + pitch
A
detect between 20Hz-10Khz
peak sensitivity of 2-3 khz
7
Q
presbycusis
A
hearing loss that occurs in old age
typically an age-dependent decrease in the upper limit of the freq range (loss of high freq hearing)
8
Q
parts of external ear
A
auricle- collects sound
external meatus- boost
9
Q
what does middle ear do?
A
energy boost (200x)
attenuation reflex
connection to nasopharynx via Eustachian tube
10
Q
what does energy boost mean?
A
avoid loss by reflection from air to fluid
larger tympanic membrane to smaller oval window
mechanical advantage/lever action of ossicles
11
Q
attenuation reflex components
A
tensor tympani muscle
stapedius muscle
12
Q
hyperacusis
A
extra sensitivty
13
Q
how much of a boost does external acoustic meatus provide
A
30 - 100 fold
14
Q
how mcuh does middle ear boost sound pressure?
A
~200 fold
via energy advantage (larger tympanic focussed to smaller oval window) and mechanical advantage (ossicles)
15
Q
two muscle of middle ear
A
tensor tympani- trigeminal nerve
stapedius- facial nerve
16
Q
how do muscles work?
A
contract by loud noises–>stiffen ossicles and reduce sound pressure to cochlea
17
Q
pharyngeal end of Eustachian tube
A
normally closed, but provides a pathway for equalizing pressure so if it gets blocked build up of pressure can hurt
18
Q
3 things in inner ear
A
cochlea
basilar membrane
organ of corti
19
Q
4 things in cochlea
A
scala vestibuli
scala tympani
scala media
stria vascularis
20
Q
scala vestibuli
A
perilymph
21
Q
scala tympani
A
perilymph
22
Q
scala media
A
endolymph (high K+)
23
Q
stria vascularis
A
produces endolymph
24
parts of organ of corti
tectorial membrane
| hair cells
25
stereocilia deflected away
hyperpolarize
26
stereociliar deflected towards kinocilia
depolarize
27
inner hair cells
afferent innervation sends info
28
outer hair cells
efferents from superior olive
29
what do efferents do
dampen response to loud sound
30
length of hair cells
lengthen in response to hyperpolarization
| shorten in response to depolarization
31
molecular motor of hair cells
prestin
32
cochlea
coiled tube where soundwaves are transformed to neural impulses
33
what separates cochlea into three compartments
cochlear duct
34
what produces endolymph
stria vascularis (secretory epithelium)
35
how are vestibuli and tympani connected?
helicotyrema
36
when pressure waves come through the oval window
transmits pressure waves into the scala vestibuli
37
shape of basilar membrane
narrower and stiffer at base--vibration during high freq
wider and more flexible at apex- vibe during low freq
---->tonotopy-systematic representation of sound freq along cochlea
38
rows of hair cells
3 rows outer hair cells
| 1 row of inner hair cells
39
tectorial membrane
gelatinous membrane- stereocilia are stuck in this
40
kinocilium
tallest stereocilium (only true cilia) disappears shortly after birth
41
stereocilia are displaced when
basilar membrane moves
42
stereocilia away from kinocilia
K+ channels close, cell hyperpolarizes, less Ca enters through Vgated Ca channels-->less NT release
43
stereocilia moves towards kinocilia
K channels open-->K flows in-->cell depolarizes-->more NT release
44
where does K flow when channels are open
INTO cell to drive to 125 mV of transmembrane potential
45
inner hair cells are connected to
afferent fibes
46
outer hair cells are targets of
```
efferent supply (which comes from superior olivary compelx)
-->Ach release from outerhair cells-->dampened response to loud sound (less response in afferent)
```
47
electromotility
depolaarization-->outer hair cells shorten-->more basilar membrane movement-->inner hair cell displacement
hyperpol-->outer hair cells lengthen
48
prestin
voltage-sensitive motor protein in outer hair cells
49
where is prestin found?
plasma membrane
50
furosemide
intereferes with outer hair cell contraction-->decreases cochlear amplification
51
cochlear amplifier
change in the exten of basilar membrane movement
52
advantages of cochlear amplifier
- -protects cochlea from damage by loud sounds
| - -dampen background noise and selectively enhance specific frequencies
53
spiral ganglion
afferent nerves from cochlea
54
analysis of frequency
dorsal cochlear nuclei
55
sound localization
ventral cochlear nuclei
56
time delay
medial superior olive neurons
57
intesnity difference
lateral superior olive
58
integrate with somatosensory info
projection to inferior colliculus
59
Two brainstem mechanisms for sound localization
time delay
| intensity differences in each ear
60
path of 8th nerve
```
dorsal/ventral cochlear nuclei
superior olivary nuclei
inferior colliclulus
medial geniculate of thalamus
superior temporal gyrus of cortex
```
61
below 3 Khz use
time delay
62
above 3Khz use
intensity differneces
63
maximum time difference that will occur in humans
0.6 ms
64
humans can detect time differences as little as
5 microseconds
65
coincidence detectors are found in the
neurons of hte medial superior olive
66
coincidence detectors
have dendrities that receive information from two ears
| stimulated maximally when info from each ear arrives at the same time
67
if the length of the dendrite differs for the axons from each ear
there will be COINCIDENT ARRIVAL depending ont he delay between thw two ears, so the cell will be stimulated best when the sound originates from one ear or the other
68
lateral superior olive neurons
stimulated by sound from ipsilateral
| inhibited from sound coming from contralateral via interneurons in medial nucleus of trapezoid body
69
for low frequency sounds that are continuous
difference in the time that it takes for a particular point in the phase of the sound wave to reach each ear can also be used to localize source of sound
70
inferior colliculus
integration of auditory information with other somatosensory inputs frm the body
**startle reflex & vestibulo-ocular reflex
integration of auditory/space map
sounds filtered out
71
4 aspects of primary auditory cortex
superior temporal gyrus
tonotopic projection
columnar orgnaization
cells specific for combinations of sounds
72
secondary auditory cortex
cells sensitive to combinations of sounds
73
wernickes area
comprehending speech
74
columnar organization
all cells in a verticle column have same best frequency
75
secondary auditory areas (belt areas)
neurons sensitive to specific combinations of sounds used in vocalizations
76
wernicke's area
posterior to primary auditory cortex
| understanding speech -->receives input from visual areas of cortex as well as auditory
77
ventral stream
primary auditory cortex & inferior frontal gyrus being responsible for pitch of sound
78
dorsal stream
superiro frontal gyrus & superior parietal cortex
| involved in determining location of sound
79
phonemes
sounds that make up human speech
80
lexemes
correspond to sound groups "th" or "st" or short words like "we"qech
81
echolocation
emit sounds and listen for echoes reflected from their target
82
echolocation in humans shows activity in..
auditory cortex
| occipital lobe
83
doppler shift
frequency of sound shifts if the object is moving
| 1kHz= approx 3 m/s
84
Broca's area
produces speech
85
Broca's area sends projections to..
motor cortex controlling mouth and lips
| a lesion= broca's aphasia
86
wernicke's area receives input from
auditory cortex and from visual system
| lesion= wenicke's aphasia= can speek but not understand speach
87
arcuate fasiculus
fiber tract that connects wernicke's area to Broca's area
| lesion= similar t broca's aphasia
88
supermarginal gyrus
neurons in this region are important for matching incoming sounds received by auditory system (speech) with phenmes that indivudals find meaninful
89
angular gyrus
neurons in this region are important for matching incoming visual information (graphemes) to phonemes that are meaningful
90
McGurk Effect
explains the interaction between auditory and visual information when understanding speech
a listening is presented with audio recording of syllable "pa", while watching a video of face saying "ka" and a majority will report hearing "ta"
91
combination sensitive neurons
neurons in the auditory association areas respond better to specific combinations of tones than tones a lone
92
Broca's area and music
important for determining whether a note is on or off key
93
pathway for music
primary auditory cortex-->auditory association zones in temporal zone--> inferior frontal cortex in R & L hemispheres
94
perfect pitch
ability to attach verbal labels to individual tones for a large set of notes
95
pitch changes
temporal regions of the R hemisphere
96
congenital amusia
tone deafness--->cant detect PITCH
about 4% of population
abnormalities in auditory cortex and inferior frontal cortex
97
timbre is processed..
right frontal cortex/hemisphere
98
rhythm, pitch, familiarity
left hemisphere
99
changes in the brain upon musical training
increases in motor areas & auditory areas (Heschl's gyrus)
100
presbycusis
late onset hearing impairment
| occurs with old age and usually due to loss of hair cells & loss of high frequency end of sound spectrum
101
hyperacusis
reduced tolernace to ordinary environmental sounds
| -->damage muscles of middle ear, or the mechanisms that control them (Bell's palsy)
102
auditory agnosia
cannot verbalize the meaning of a nonverbal sound
103
conduction deafness
disturbance in the conduction of sound from the outer ear to the cochlea
can be due to.. wax in the ear, tympanic membrane rupture, pathology of ossicles
104
sensorineural deafness
loss of hair cells or neurons in auditory nerve
105
acquired hearing loss
acoustical trauma
infection of inner ear
ototoxic drugs (kanamycin, gentamycin)
old age (presbycusis)
106
genetic causes of hearing loss
nearly 50 genes have been identified
absence of K channels in hair cell cilia, absence of proteins necessary for proper alignment of cilia, inability to produce high K+ containing endolymph in cochlea
107
rinne test
can be used to distinguish between conduction deafness and sensorineural deafness
108
rinne test results
conductive hearing loss- bone conduction heard longer than air conduction
sensorineural hearing loss- air conduction is heard longer than bone conduction but less than twice as long
109
tinnitus
perception of sound in absence of stimulus
| --often accompanies disorders involving cochlea, auditory nerve, or even changes in auditory cortex
110
acoustic neuroma
slow growing tumors of schwann cell origin
originate in vestibular nerve-->but can influence cochlear nerve as well
can result in hearing loss and/or tinnitus
111
Meniere's Disease
progressing hearing loss (often in the low freq range) due to excess fluid buildup in endolymphatic sac surrounding cochlea
cause unknown, though could be due to blockade or restriction of endolymphatic duct or in production of endolymph by stria vascularis
112
how can you make hair cells regenerate
induce non-sensory epithelial cells of cochlea to differentiate into hair cells
virus mediated gene delivery of Math1/Atoh1 -->generation of hair cells with innervation and function
113
cochlear implants
microphone on side of head sends signals to a processor-->converts freeq information into digital signal-->info sent to receiver under scalp-->sends signal through wires threaded into cochlea-->selectively stimulate auditory nerve at various places along cochlea
114
issues with cochlear implants
timbre perception is poor (ability to caputre emotional content/prosody) also poor
combo of visual/auditory is poor
115
optic tectum
owl equivalent to superior colliculus
116
if child gets a cochlear transplant after 2.5 years old
not too much successwith visual auditory fusion
