Audiology: Exam 2 Flashcards
What is a pure tone threshold?
The lowest level at which a person responds to a tone
At how many frequencies is a pure tone threshold taken?
It is obtained at different frequencies to determine whether hearing loss is present
How can pure tones be obtained?
1 - air conduction
2 - bone conduction
What is used during air conduction?
headphones, insert phones, or speakers
What is used during bone conduction?
A bone conduction oscillator that is placed on either mastoid or head
What is the method used during pure tone testing?
You can either have the patient do a hand raise, press the button, or says “yes”
What is a true response?
The client accurately responds - they hear it, raider their hand or they don’t hear it and don’t raise their hand
What is a false response?
They inaccurately respond - they hear it and don’t raise hand or they don’t hear ir and raise hand
What is a positive response?
A response that you heard it (hear it and raise hand; tinnitus - hear own and raise hand; vibrating and raise hand but don’t really hear it; IA - raise hand because the good ear heard it)
What is a negative response?
When you don’t respond (faking it, misunderstood, asleep, too young, hearing tinnitus)
What is a true positive response?
when they accurately say they heard it
What is a true negative response?
when they accurately don’t respond
What is a false positive response?
inaccurately responded - said they heard it when they didn’t
What is a false negative response?
inaccurately say they didn’t hear sound (faking it, did not understand directions, sleeping)
Where do you start for the beginning of an evaluation?
ASHA says to begin at 30dBHL at 1000Hz or a level a person can hear
How long should you present the tone during an evaluations?
One to two seconds in duration
For the start of an evaluation, if the patient does not respond at 30dBHL, what should you do?
Increase to 50dBHL and increments of 20dBHL until you receive a response.
When do you begin a threshold search?
When the patient responds to the first tone
What is the ascending-descending approach?
When you are searching for threshold, we use the down 10dBHL, up 5dBHL method.
When a patient responds to the initial tone, what do you do?
You drop 10dBHL until you get no response
What do you do after you drop 10dBHL and get no response?
You ascend 5dBHL until you get a response
What is the lowest level at which a patient responses?
You must repeat the down 10, up 5 until the patient responses 2 or 3 times, giving you the lowest level
What frequencies are tested for air conduction?
1000, 2000, 4000, 8000, 1000, 500, 250
Also inter-octaves: 750, 1500, 3000, 6000
What frequencies are tested for bone conduction?
1000, 2000, 4000, 500, 250
Sometimes 6000
Also inter-octaves: 750, 1500, 3000
What is the symbol on the audiogram for the left ear, air conduction?
X
What is the symbol on the audiogram for the right ear, air conduction?
O
What is the symbol on the audiogram for the left ear, air conduction?
>
What is the symbol on the audiogram for the left ear, bone conduction?
<
What is the three frequency pure tone average?
the average of the thresholds at 500, 1000, and 2000Hz
What is the two frequency pure tone average?
the average of the two best threshold of 500, 1000, and 2000Hz
How do you interpret an audiogram?
You look at each ear separately and you describe: degree of hearing loss, nature of hearing loss, and audiometric configuration
What are the degrees of hearing loss?
normal, slight (children only), mild, moderate, moderately-severe, severe, and profound
What is a normal degree of “hearing loss?”
0-15dBHL
What is a mild degree of hearing loss?
26-40dBHL
What is a moderate degree of hearing loss?
41-55dBHL
What is a moderately-severe degree of hearing loss?
56-70dBHL
What is a severe degree of hearing loss?
71-90dBHL
What is a profound degree of hearing loss?
91dBHL+
What is the nature of hearing loss based on?
presence or absence of air-bone gap
What is a normal hearing loss?
When the BC agrees with AC and both are within normal limits
What is a conductive hearing loss?
When the BC is within normal limits and AC shows a loss
What is sensorineural hearing loss?
When the BC agrees with the AC and both show a hearing loss
What is a mixed hearing loss?
When the BC shows a loss but AC also shows loss even greater than BC
What are the audiogram configurations?
Flat (each threshold is within 10dB), gradually sloping, steeply sloping or markedly sloping, rising, and ski-slope or precipitously sloping
What are the ASHA guidelines for a pure tone screening?
Test frequencies 1000, 2000, and 4000Hz at 25dBHL (adults)
What does a failure of a pure tone screening consist of?
A lack of response to any one frequency in either ear
What is speech detection threshold (STD)?
the lowest level speech can be barely detected; also called speech awareness threshold (SAT)
COME BACK TO SLIDE 25
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What is the speech recognition threshold?
lowest hearing level speech is understood
How much louder is the SRT then the STD usually?
10dB and should agree with the PTA by 10dB
How do you classify the degree of hearing with SRT?
the same as pure tones
How is the SRT obtained?
by using spondaic words or “spondees;” two-syllable, compound words (doormat, cupcake, mousetrap, football) with equal stress
What should you remember when using SRT words?
make sure the client is familiarized with all the words before the threshold search, make sure you are using age-appropriate words, and discard unfamiliar spondees
What is a speech recognition score?
Phonetically based (PB) list of monosyllabic words presented at comfortable level for the patient (30-40dBSL) such as you, could, what, bathe, ace
What must you use when giving the PB list of words?
a carrier phrase
What categories do the SRS% scores have?
excellent, good, fair, poor, and very poor; usually 25 or 50 words - score is percent correct
Excellent SRS% score
90-100%
Good SRS% score
80-89%
Fair SRS% score
70-79%
Poor SRS% score
50-69%
Very Poor SRS% score
Less than 50%
What is the most comfortable loudness (MCL)?
continuous discourse is ideal to obtain MCL - ask patient to rate level of speech in terms of comfort
What is the normal listeners range of MCL?
40-55dBHL
What is the range for hearing loss given MCL?
it depends on the degree of hearing loss
What is uncomfortable loudness (UCL)?
continuous discourse is ideal to obtain UCL - can also use tones; ask the patient to rate the level of speech in terms of comfort
What is a normal listeners range of UCL?
100-110dBHL
What is a hearing impaired range of UCL?
it varies based on degree of loss but often lower levels than normal hearing listeners (those with senorineural loss)
What is dynamic range (DR)?
difference between SRT and UCL; it is also known as range of comfortable loudness (RCL)
What is the DR for normal listeners?
100dB
What is the DR for hearing impaired-sensorineural loss?
usually much less than normal hearing listeners
What is masking?
presenting a signal to one ear to mask its ability to respond when a signal is presented to the other ear
Why do we mask?
we want to make sure the ear we are testing is actually responding
When do we mask?
whenever a response is potentially attributable to the non-test ear; must first obtain threshold and consider inter aural attenuation
What is Interaural Attenuation (IA)?
When the loss of intensity of sound introduced to one ear and heard by the other ear
What is the IA of circumaural headphones?
40dBHL
What is the IA of insert headphones?
55dBHL
What is the IA of bone conduction?
0dBHL
When should you mask with air conduction?
When the AC threshold is greater than or equal to the AC or VC of the non test ear
When should you mask with bone conduction?
When the air bone gap of the test ear is greater or equal to 15dB
When to mask for SRT testing
SRT of test ear is greater than or equal to SRT or best BC of non test ear
When to mask for suprathreshold of speech testing?
if you had to mask for SRT you will have to mask for suprathreshold (slide 39)
How does it work?
only when we occupy the non-test ear, can we assume we are truly measuring the test ear
Stenger Effect
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Narrowband noise
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Masking for speech
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What is effective masking?
sufficiently masking the non-test ear and allowing the test ear to be measured accurately without the risk of under or over masking
What is minimum masking?
minimum intensity of noise required to effectively mask
What is maximum masking?
The maximum intensity allowed before risking overmasking
What is undermasking?
not enough noise is presented to the non-test ear and they still are responding to the tone in the non-test ear
What is overmasking?
The masking noise level is too intense in the non-test ear and is crossing back to the test ear and interfering with threshold measurement
What is central masking?
Threshold becomes 5dB poorer; increase of threshold by 5dB due to inhibition central auditory system; any time you mask, you may see a 5dB change just because you masked even if masking was not necessary
What is the symbol for left ear masked air conduction?
.
What is the symbol for right ear masked air conduction?
.
What is the symbol for left ear masked bone conduction?
}
What is the symbol of the right ear masked bone conduction
{
What is the objective tests of the auditory system?
Immittance testing (tympanometry, acoustic reflex threshold, acoustic reflex decay), otoacoustic emissions (OAEs), and auditory brainstem response (ABR)
What is tympanometry?
a measure of the pressure of the air contained in the middle ear space; 226 Hz probe tone presented while the pressure in the ear canal is changed from positive to negative; the probe tone is used to measure ear canal volume (ECV) and static compliance
What is static acoustic compliance?
a measure of how the tympanic membrane in response to pressure changes
What are the normal peak static acoustic compliances?
Infant: 0.25-0.92mmho
Child: 0.25-1.5mmho
Adult:0.3 - 1.7mmho
What is pressure?
the pressure at which the tympanic membrane is at maximum static compliance
What are normal pressures?
+50 to -100daPa
What is ear canal volume (ECV)?
a measure of the volume of the ear canal
What are the normal levels of ECV?
Young children: 0.3 to 0.9 cc
Older children: 0.6 to 1.5 cc
Adult: 0.6 to 2.0cc
What is a type A tympanogram?
Normal
What is a type As tympanogram?
s - stiff or shallow; stiff middle ear system (peak is less than normal) but normal pressure
What is type Ad tympanogram?
d = disarticulated or deep; flaccid or hypermobile ear system (peak is greater than normal) and normal pressure
What is a type B tympanogram?
flat; extreme stiffness or immobility of the middle ear (no peak or pressure)
What is a type C tympanogram?
negative pressure but normal compliance
How is acoustic reflex (AR) measured?
uses the same equipment as tympanomertry
How is acoustic reflex threshold (ART) found?
tone presented to elicit stapedius muscle; ipsilateral and contralateral stimulation
How is acoustic reflex decay (ARD) found?
tone presented to elicit the stapedius muscle at 10dB above ART
What levels is ARTs obtained?
500, 1000, 2000, and 4000Hz; measured at peak compliance
Do many normal hearing have ART at 4Hz?
no
How is contralateral stimulation possible?
because at the superior olivary complex it crosses over to other side causing AR via the facial nerve
What is normal hearing given the ART score?
85dBSL
What is a mild to moderate SNHL?
ART at Low ST
What is a severe SNHL or 7th nerve problem?
absent ART
