Audiology Flashcards
What are the three parts of the cochlea?
Scala vestibuli, scala media, scala tympani
What is contained in the scala vestibuli?
The oval window and Reisner’s membrane. It’s filled with perilymph
What is contained in the scala media?
Reisner’s membrane, organ of corti, stria vascularis. Full of endolymph
What is contained in the scala tympani
the circular window. full of perilymph
What is the oval window?
The oval window is the place where the incus and stapes push against to move the fluid through the cochlea
what is the circular window?
It’s the “exit” of the cochlea. it moves to accomadate pressure
What is Reisner’s membrane?
It’s the thing that separates the scala vestibuli from the scala media
What separates the scala tympani from the scala media?
The baslar membrane
The numatic amplification of the lever action of the malleus, incus, and stapes makes sound how many times louder?
22 times
How many rows of outer hair cells are there?
3
Which two membranes border the organ of corti?
the tectoral membrane (above) and the baslar membrane (below)
what tones are tested in pure tone audiometry?
250, 500, 1000, 2000, 4000, 8000
Threshold is the lowest level the patient responds what percent of the time?
50%
What is the range of normal hearing thresholds for kids?
-10 to 15dB
What is a normal hearing threshold for adults?
25dB
Mild hearing loss is from
26 to 40 dB
difficulty with only faint speech
Moderate hearing loss is from
41 to 55 dB
frequent difficulties with normal speech
Moderate-severe hearing loss is from
56-70 dB
frequent difficulty with loud speech
Severe hearing loss is from
71-90 dB
Can understand only shouted or amplified speech
Profound hearing loss is
91dB+
usually cannot understand even amplified speech
Most speech sounds are between
20-50dB
Air conduction tells us what about hearing loss?
degree
Bone conduction with air conduction tell us what about hearing loss?
type
How do you calculate pure tone average?
add thresholds from 500, 1000, 2000 and divide by three
what is the occlusion effect and what frequencies does it affect?
amplification of low sounds due to covering ears.
250- 30dB
500- 20dB
1000- 10dB
If you have normal air conduction, what will your bone conduction be?
normal
Interaural attenuation is
loss of energy of a sound as it travels from test to non test ear
0 dB bone conduction
40 dB supra aural earphones
50 dB inserts
If you’re using supra aural earphones and send 60dB into your right ear, how much sound would reach the left ear?
20 dB
because interaural attenuation with headphones is 40dB (meaning 40dB are lost to absorption or the environment) 20dB are left to reach the non test ear
If you’re using bone conduction on the mastoid and send 30dB to your left ear, how much sound would reach the right ear?
30dB
because interaural attenuation for bone conduction is zero, meaning no sound is lost so all of it will go the non test ear
Hearing loss is described by
degree shape degree type
ex. mild sloping to severe sensorineural HL
What are the audiogram shapes
flat, rising, sloping, precipitous (more than 20dB difference between 2 octaves)
What is atresia?
Absence of external auditory canal
What is microtia?
abnormally small pinna
What is macrotia?
abnormally large pinna
what is anotia?
absence of pinna
Which syndrome is more predisposed to atresia or stenosis of the EAC?
Treacher collins syndrome
Right AC symbol
O
Left AC symbol
X
Right BC symbol unmasked
<
Left BC symbol unmasked
>
Right AC symbol masked
Triangle
Left AC symbol masked
Square
Right BC symbol masked
[
Left BC symbol masked
]
What is the external auditory meatus?
The ear canal
What is otalgia?
ear pain often caused by foreign bodies causing swelling in EAM
What is external otitis?
swimmer’s ear. It’s an inflammatory disorder in the skin of the pinna, EAM or both. Caused by trapped water. skin gets swollen, hot to the touch, and sloughs off
Speech discrimination (WRT) scores will be normal with what kind of hearing loss?
conductive because WRT is a supra-threshold test
What is tympanosclerosis?
Scarring of the ear drum. can be caused by scar tissue after a TM perforation. Scar tissue affects mobility of ear drum and therefore hearing ability
what is a myringoplasty?
a surgery to fix the tympanic membrane. put tissue or surgical paper over the perforation on TM.
What can cause TM to burst?
flying, diving, and ear infections
perforation of TM causes what kind of hearing loss?
Conductive
What is otitis media?
ear infection (middle ear) due to eustachian tube dysfunction.
What is the process of otitis media?
- eustachian tube dysfunction (not opening and closing to equalize pressure
- negative pressure
- Vacuum effect which absorbs O2 in middle ear space
- Vacuum pulls fluid from cells lining middle ear space
- Fluid causes positive pressure
- positive pressure and excess fluid cause TM to bulge
- If nothing is done pressure will continue to build until ear drum perforates
- Ear drains
- TM heals
- If eustachian tube dysfunction is not resolved the cycle will repeat
What is cholesteatoma?
complication from otitis media with effusion (fluid). skin in middle ear space erodes bones around it. critical to fix b/c it could eventually affect brain. requires surgery. (tympanoplastey, mastoidectomy, tympanomastoidectomy, ossiculoplasty)
what is a myringotomy?
a surgery where they make a small incision in the tympanic membrane and insert a tube which stays in anywhere from 6months to a year
otosclerosis
middle ear pathology
-results in conductive or sensorineural HL depending on stage
-begins with growth of spongey bone on stapes (otospongeosis) causing conductive loss
-later hardens to become boney
Carharts notch (a dip in BC at 2000 Hz. sometimes also an increase in AC at 2000) is a type of mixed HL seen in what middle ear pathology?
otosclerosis
what is presbycusis
age related sloping sensorineural hearing loss. characteristic normal low frequencies sloping to HL in high frequencies. occurs in 60% of population over 65. most common treatment is hearing aids.
what is meniere’s disease? (also called endolymphatic hydrops)
excess endolymph fluid which causes pressure. results in awful vertigo/spinning sensation, tinnitus, and fluctuating unilateral SNHL
ototoxicity
Killing off of inner hair cells by medications like IV antibiotics, chemo, diuretics, sedatives, quinine, and more. symptoms start with tinnitus, then HL, then vertigo.
noise induced hearing loss will show a notch between what frequencies
4k and 6k
What kind of hearing loss has normal BC and abnormal AC with an air bone gap?
conductive
What kind of hearing loss has abnormal AC and BC w/o an ABG?
SNHL
What kind of hearing loss has abnormal AC and BC w/ an ABG?
Mixed
what is the formula for finding out if you need to mask in air conduction?
ACte - BCnte >/= IA
What is the formula for finding out how much you need to mask for AC?
ACte + 15
What is the formula for finding out if you need to mask in bone conduction?
ABgap >/= 15
What is the formula for finding out how much you need to mask in bone conduction?
ACnte + occlusion effect + 15
Go describe the hearing losses on this audiogram and find out the PTA and if and how much masking you need for AC and BC https://quizlet.com/444303081/practice-audiograms-flash-cards/
good job!
Go write out each hearing loss degree and it’s range
normal -10 to 25
mild. 26 to 40
moderate 41 to 55
moderately severe 56 to 70
severe 71 to 90
profound 91+
Name the parts of the auditory pathway
8th cranial nerve
cochlear nucleus
superior olivary complex (soc)
lateral lemniscus
inferior colliculus
medial geniculate body
auditory cortex
what does tympanometry tell us?
whether or not there’s a pathology in the middle ear
what does tympanometry evaluate
it evaluates from the EAM to the end of the middle ear (oval window, but not cochlea)
What do OAEs evaluate?
They evaluate the cochlea to the 8th nerve
True or. false, tympanometry is a test of hearing
false, it just tells us how the middle ear is functioning. it should be used in conjunction with AC and BC
A type A tympanogram tells us what?
That everything is normal. Can show a normal audiogram or a SNHL
a Type As tympanogram has a normal pressure peak and a low (shallow) degree of compliance. What can cause this?
Limited movement of the TM due to scarring, plaque, or otosclerosis.
the tympanogram is in the center, but is super short
a type Ad tympanogram has a normal pressure peak and high (deep) degree of compliance. what can cause this?
Excessive movement of the TM due to disarticulation of the ossicles, thin or monomeric TM
the tympanogram is in the center, but is super tall
what type of tympanogram
-has no TM movement detected
-no middle ear pressure reading
-abnormally low compliance
-normal or very large ear canal volume
Type B
What type of hearing loss can you expect with a type B tympanogram?
conductive or mixed hearing loss. recommend medical referral
What can cause a type B tympanogram
-wax if ear canal volume is small
-fluid if volume is normal
-PE tube if volume is huge
What type of tympanogram is a flat or slanted line with normal volume, but no peak
Type B
In a type C tympanogram is it pressure or volume that is abnormal?
pressure peak outside the normal range
What does a type c tympanogram suggest about middle ear pressure?
there is significant negative pressure in the middle ear
What can cause a type C tympanogram
allergies, blocked eustachian tube, developing or resolving middle ear infection. may or may not cause conductive HL
What recordable sound is generated by basilar membrane vibration (caused by outer hair cell movement) and echoes or leaks out of the ear canal?
Otoacoustic emissions (OAE)
present OAEs mean what?
-good outer hair cell function
-good middle ear transmission
-PTA 30dB or less
If you have any hearing loss at all, can you still have an OAE
Nope
True or false, OAE’s are function detectors not hearing measures
true
What is an ABR?
auditory brainstem response. measures brainstem response (8th nerve and above)
which is more thorough? OAE’s or ABR’s
ABR’s because they go from the EAM through the auditory pathway
What three things do ABR’s look at?
Latency-how long does it take the wave to show up
amplitude- how high
morphology- sharp peaks?
How many waves does an ABR have?
3, each pertaining to a different park of the auditory pathway
what part of the auditory pathway does wave 1 of an ABR pertain to?
8th cranial nerve
what part of the auditory pathway does wave 2 of an ABR pertain to?
also the 8th cranial nerve
what part of the auditory pathway does wave 3 of an ABR pertain to?
cochlear nucleus
what part of the auditory pathway does wave 4 of an ABR pertain to?
superior olivary complex (soc)
what part of the auditory pathway does wave 5 of an ABR pertain to?
lateral lemniscus and inferior colliculus
Go read “relationship of mild hearing loss to listening and learning needs” page in pdf
good job
Go read “relationship of moderate hearing loss to listening and learning needs” page in pdf
good job
Go read “relationship of moderately severe hearing loss to listening and learning needs” page in pdf
noice
Go read “relationship of severe hearing loss to listening and learning needs” page in pdf
you go girl
Go read “relationship of profound hearing loss to listening and learning needs” page in pdf
nicely done
