audiology Flashcards
1
Q
what is the resonant frequency of the ear canal
A
2500 Hz
2
Q
what frequency of sounds does the tympanic membrane respond to
A
low
3
Q
what bones are in the ossicular chain
A
- malleus which is embedded in the tympanic membrane
- incus which is connected in a tight joint that permits little movement
- stapes which inserts into the oval window
4
Q
what is the amplification of sound by the ossicular chain
A
30 dB
5
Q
which muscles dampen vibrations of the tympanic membrane
A
- tensor timpani: innervated by V and is the smallest muscle in the body
- stapedius muscle which stiffens the chain to reduce vibrations
6
Q
what is the acoustic reflex
A
the tympanic membrane stiffens toprotect the ears
7
Q
what is the function of the eustachian tube
A
- maintains equal air pressure in middle ear
8
Q
how does the eustachian tube function
A
- tensor veli palatini aids in opening
9
Q
what is the oval window
A
small opening in the temporal bone that houses the inner ear
10
Q
what are the labyrinths or tunnels in the inner ear filled with
A
a fluid called perilymph
11
Q
what are the major structures in the inner ear
A
- vestibular system
2. cochlea
12
Q
what fluid fills the cochlea
A
endolymph
13
Q
what ies on the floor of the cochlear duct that transmits sound
A
basilar membrane which contains the organ of corti
14
Q
what are the hair cells called
A
cilia
15
Q
how is sound transmitted through the cochlea
A
- vibrations from the footplate of the stapes create wave movements in the perilymph
- through REissners membrane, the movements are transmitted to the endolymph which transmits movement to the basilar membrane
- at the tip or apex the membrane is thicker, wider and more lax than the base
- low frequency sounds stimulate the apex and high frequency stimulate the base
- the cilia respond to the vibrations and are sheared. This turns the energy into electric which stimulates nerve endings
16
Q
where do the auditory nerve fibers exit the inner ear
A
internal auditory meatus
17
Q
what does hertz mean
A
cycles per second. 200 Hz means 200 cycles per second
18
Q
what is the normal sound pressure level of speech
A
50-70 dB
19
Q
what is the pain threshold for sound pressure
A
140 dB
20
Q
what is the hearing level
A
lowest intensity of a sound necessary to stimulate the auditory system. THe hearing level is the audiometric zero
21
Q
the human air is most sensitive to sounds in what frequency range
A
100-4000 Hz
22
Q
at what age can a baby turn its head towards sound`
A
3 to 4 months
23
Q
what factors increase a child at risk for hearing loss
A
- malformation of the head and neck
- maternal history of drugs or alcohol abuse
- maternal diseases (rubella, syphilis) during pregnancy
- genetics
24
Q
what are the degrees of hearing loss
A
16 to 25 dB HL: slight 26-40 dB HL: mild 41-55: moderately 56-70: moderately severe 71-90: severe
25
why is conductive hearing loss never profound
there is always some hearing left because of bone conduction
26
what are the causes of conductive hearing loss
1. abnormalities of the external auditory canal, tympanic membrane, or ossicular chain
2. birth defects, diseases, and foreign bodies
3. aural atresia, microtia, stenosis
4. external otitis: infection of the skin of external auditory canal
5. foreign objects in the ear canal and bony growths
6. otitis media
7. otosclerosis
8. otospongiosis
9. ossicular disconuity
27
what is aural atresia
where the external ear canal is completely closed
28
what is microtia
small pinna
29
what are the characteristics of otitis media
1. creates a conductive loss of 20-35 dB HL which often goes undetected in pure tone screens which are carrie out at 25 dB HL
2. serous otitis media: the middle ear is inflamed and filled with fluid. The Eustachian tube is blocked so fresh air does not ventilate. The middle ear becomes airtight. Increased air pressure out side the middle ear pushes the tympanic membrane inward reducing mobility
3. acute otitis media: sudden onset due to infection. Quick build up of fluid causing pain. Child has fever. May cause the tympanic membrane to rupture. treated by myringtomy where a small incision in tympanic membrane relieves pressure
4. chronic otitis media: from permanent damage to middle ear structures due to erosion of ossicles, cholosteotoma, atrophy or perforation of tympanic membrane
30
what is otosclerosis
spongy growth starts on the footplate and they become rigid so the stapes does not move into the oval window
31
what is Carhart's notch
pattern of bone conduction thresholds characterized by reduced bone-conduction sensitivity at 2000 Hz
32
what is otospongiosis
disease that causes the stapes to become too soft to vitrate. The stapes is surgically removed by stapedectomy and a prothesis is inserted
33
what is ossicular discontinuity
discontinuity of the ossicuar chain
34
what are the characteristics of sensorineural hearing loss
1. both bone and air conduction are impaired so people have difficulty hearing themselves
2. high frequencies tend to be more profound than low
3. a symptom of hearing loss is recruitment which makes a person hypersensitive to intense sounds
35
what are the causes of sensorineural hearing loss
1. prenatal loss: drugs by mother during the 6th and 7th week
2. ototoxic drugs: antibiotics (mycins)
3. genetic factors
4. noise: prolonged exposure to intense sounds. Loss most profound between 3000 and 6000 Hz
5. birth defects
6. STORCH
7. acoustic neuroma
8. presbycusis
9. Meniere's disease
36
what is STORCH
major causes of hearing loss in fetuses and newborns
1. Syphilis
2. Toxoplasmosis
3. Rubella
4. Cytomegalovirus
5. Herpes
37
what is Meniere's disease
1. condition caused by fluctuating sensorineural hearing loss
2. due to excessive endolymphatic fluid pressure in the labyrinth which causes Reissner's membrane to become extended
3. symptoms include hearing loss, dizziness, sense of fullness in the ear, and tinnitus
38
what are central auditory processing disorders
hearing loss due to disrupted sound transmission between the brainstem and the cerebrum. The temporal cortex receives incorrect info
2. disorder in a person's ability to take in a spoken message, interpret it, and make it meaningful
3. there is no significant peripheral hearing loss
4. difficulty understanding distorted speech is a major symptom
39
what causes central auditory disorders
1. tumors
2. TBI
3. HIV
4. asphyxia during birth
5. genetics,
6. infections such as meningitis
7. metabolic disturbances
8. cardivascular disease
9. dementias and demylenating diseases
40
what are dichotic listening tasks
listener must process different messages presented simultaneously to both ears
41
what are the characteristics of a central auditory disorder
1. poor auditory discrimination
2. poor auditory integration
3. poor auditory sequencing skills
4. difficulty listening when background noise exists
5. por auditory attention
6. poor auditory memory
7. poor auditory localization
8. difficulty understanding rapid speech
9. difficulty following melodic and rhythmic elements of music
10. academic problems
11. difficulty with vocab and pragmatics
42
what are retrocochlear disorders
due to damage to nerve fibers along the ascending auditory pathway from the internal auditory meatus to the cortex
43
what causes retrocochlear disorders
unilateral tumors or acoustic neuromas
44
what are the symptoms of acoustic neuromas
1. unilateral high frequency hearing loss
2. tinnitus
3. disequilibrium
4. alterations of facial sensation and mvement due to facial and trigeminal nerve damage
5. pain and headach in the ear and mastoid
6. feeling of fullness in the affected ear
7. balance problems
45
what is von Recklinghausen disease
inherited disease characterized by numerous small tumors that grow slowly along peripheral nerves
46
what frequencies are generated by an audiometer
125, 250, 500, 750, 1000, 1500, 2000, 3000, 4000, and 8,000 Hz
47
what is a threshold
an intensity level at which a tone is faintly heard at least 50% of the time
48
which frequency is the first presented in an audiogram
1000 at 30 dB then up to 50 and 60 if the patient does not respond. Once the patient responds, decrease by 10 dB until no reponse, then increase by 5 dB until you get a response
down 10 up 5 pattern
49
what is a speech reception threshold
lowest level of hearing that a person understands 50% of spondee words
50
what is acoustic immittance
transfer of acoustic energy
51
what is impedance
resistance to the flow
52
what is admittance
amount of energy that goes through the system
53
what is tympanometry
a procedure that measures acoustic immittance
2. a sound stimulus is placed in the external ear canal with airtight closure.
3. the changes in the acoustic energy are measured
4. instrument helps create either negative or positive change in the ear canal. Acoustic immittance is altered by air pressure changes
54
what is acoustic reflex testing used for
detects middle ear disease
55
what are auditory-evoked potentials
electrical changes produced by sound stimuli
56
what is an Auditory brainstem response
a technique used to record electric activity in the auditory nerve, brainstem, and cortex. Useful in detecting brainstem disease and helpful in testing newborn hearing
57
how is a hearing screening administered
1. pure tones presented at 20-25 dB
| 2. the frequencies of 500, 1000, 2000, and 4000 are tested
58
what are the 2 primary types of newborn hearing screening
1. otoacoustic emissions
| 2. auditory brainstem response
59
what is visual reinforcement audiometry
used with older infants
| a sound is presented to see wheter the infant will turn towards it
60
what is behavioral observation audiometry
used when infant is not able to turn the head and use visual reinforcment
61
what is an air-bone gap
indicates a conductive hearing loss
when bone conduction is normal and air conduction is abnormal
a difference of 10 dB or more implies a conductive loss
62
what is acoustic highlighting
a technique for interacting with children that involves emphasis on key words, shorter sentences, increased repetition, slower speaking rate, nearness to the listener, increased pitch and rhythm, emphasis on the ends of sentences
63
what is a behind-the-ear model of hearing aid
fits behind the ear and has an internal receiver. The components are all contained in the same case
64
what is the in-the-ear-canal model of hearing aids
fits in the canal with a case behind the ear that contains the amplifier and microphone. A small bud contains the receiver located in the ear canal
65
what are BAHA
bone anchored hearing aids. used for conductive hearing loss, single side deafness, unilateral loss or those who cant wear traditional hearing aids
66
what are cochlear implants
electronic devices that are surgically placed in the cochlea to deliver sound directly to te acoustic nerve ending
67
what are the 4 elements of a cochlear implant
1. microphone: picks up sound and converts it to electrical impulses
2. processor behind the ear over the internal magnet. It suppresses extraneous noise and selects sounds salient to comprehending speech
3. external transmitter coil: held on the head via the magnet in the internal cochlear implant
4. digitized info is sent across the skin to the receiver/stimulator via radio waves. The receiver/stimulator picks up the radio signal and sends it via a thin wire to an electrode array in the cochlea
68
what is auditory habiitation
teaches a person with hearing loss to listen to amplified of electrically transmitted sounds, recognize their meanings, and discriminate sounds
goals include discrimination of environmental and speech sounds, word pairs, phrases and sentences within meaningful tasks such as board games, show and tell etc
69
what is speech reading
deciphering speech by looking at the face and using visual cues
70
what is cued speech
may be used to supplement speech reading. It is produced with manual cues that represent the sounds of speech
2. made of 8 hand configurations
3. helps to distinguish among homopheonous sounds
71
wha is the Aural/oral method of training
use amplification with speech reading instruction so they fit well into mainstream society
72
what is the manual approach
nonverbal communication that involves signing and fingerspelling
73
what is total communication
signs and speech used simultaneously
74
what is ASL
manual signing
considered a separate language
signs are used to express ideas through complex hand and finger movements
75
what does air conduction tests tell you
the degree of loss
76
what does bone conduction tell you
type of loss
77
what is the primary objective of auditory training
improve speech recognition by using auditory cues
78
what is the hierarchy of auditory skill development
1. detection
2. discrimination
3. identification
4. comprehension
79
what are visemes
groups of phonemes that look the same on lips
80
what are homophenes
words that look the same on the mouth
