Unit 2 Flashcards
What is speech audiometry testing?
The presentation of standardized samples of speech through a calibrated system in attempt to quantify the patients ability to perceive complex information at threshold and supra threshold levels (ability to understand speech a different levels)
Detection
The level at which one becomes aware of the presence of speech
Discrimination
The level at which one is able to distinguish between individual speech stimuli
Identification
The level at which one is able to label what has been heard
What are the 2 parts of identification?
Reception and recognition
Reception
Threshold measure: focus is on assessing audibility not vocab
Recognition
Supra-threshold measure: focus is on intelligibility
Why do we do speech audiometry testing?
Communication is essential to life, high face validity (valid measure of real world task), rehabilitation( test before and after treatment), cross check for pure ton measure, differential diagnosis (HL differences contribute to different speech recognitions scores)
What are the types of speech perception tests?
Speech detection/awareness thresholds (SDT/SAT), speech reception thresholds (SRT), Speech recognition in quiet, speech recognition in noise
Purpose of SDT
To determine the lowest level that the patient can just detect the presence of speech 50% of the time
Stimuli of SDT
Spondaic words
Who do you test with SDT?
Children who don’t have large vocabulary and those with severe hearing losses
What are spondaic words
2 syllable words where both syllables are stressed (2 monosyllable words put together)
Examples of spondaic words
Baseball, hotdog, airplane, birthday, toothbrush, sunshine
Procedure for SDT
Patient instructed to listen for a word presented at a level above threshold, if response is given the level decreases 10 dB, if response occurs level is increased 5 dB, this continues until the patient response half the time and you record the threshold for speech detection
Is it hard or easy to determine the presence of HL on the basis of SDT?
Yes
What is the purpose of SRT?
To determine the lowest level at which the patient can perceive (repeat) words with 50% accuracy
What is the stimuli of SRT?
Spondaic words
What is the procedure for SRT?
The patient listens and repeats a word presented at a level above threshold, if if response is correct level decreased 10 dB, is response s incorrect the level is increased 5 dB, this continues until the patient responses correctly half the time so it is the patients threshold for speech perception
What is the interpretation of SRT involving PTA?
SRT should be within 5 dB of patients pure tone average
PTA
Pure tone average (DBat 500, 1000, and 2000 divided by 3)
If there is a steep sloping loss where should the SRT be>
Within 5 dB of the best hearing threshold
What is the purpose of WRS (quiet)?
The determine how well a patient perceives speech at levels experience in day-to-day communication
Can you determine the presence of a HL on the basis of SRT alone?
No
What is the stimuli of WRS (quiet)?
Words or sentences (phonetically balanced lists comprised of phonemes in the frequency with which they generally occur in conversational speech)
Procedure of WRS (quiet)?
The patient repeats each word or sentence presented above threshold, the percentage of words correctly repeated by the patient is recorded, performance for one or more presentation levels can be determined by descriptors of excellent, good, fair, poor, and very poor
Expectations for WRS (quiet)
At comfortable listening levels most patients should do well, these tests are very sensitive to pathologies that disrupt the integrity of the acoustic signal (something is going on past the inner ear)
Performance-Intensity function testing for normal hearing?
The scores get better and the sound singal increases
Performance-Intensity function testing for cochlear problem?
Performance increases to some maximum and remains there at higher presentation levels - still below normal
Performance-Intensity function testing for patient w neural disorders/rollover?
Rollover occurs when performance may decrease after a maximum (turn up volume) is reached
What the 2 effects of HL on speech intelligability
Audibility and distortion
Audibility
Sounds are quieter than they should be. Any time of hearing loss will cause this problem
Distortion
There is a static noise accompanying sound. Accompanies sensorineural hearing loss
Consonants determine
Clarity of speech (high pitch)
Vowels determine
Loudness/power of speech (low pitch)
High Frequency Sloping Configuration
can hear vowels and not consonants
Low Frequency Rising Configuration
can hear consonants by not vowels as well
Is outoacoustic emission objective or subjective?
Objective
What are we measuring with otoacoustic emission?
We are measuring the low-level sound that is generated by the cochlea
How do we measure and otoacoustic emission?
Place a sensitive microphone in the ear canal
What are the types of autoacousic emission?
Spontaneous & Evoked
Do we need an active cochlea for autoacousic emissions?
Yes
What are the types of evoked emissions?
Transient Evoked and Distortion Product
What is the generator of sound in autoacoustic emmission?
Outer hair cells
Transient Evoked
Short Stimulus
Distortion Products
Played 2 tones different pitches and played together to make a 3rd sound
What are the 2 components that the signal needs to have?
Forward Transmission, Backward Transmission
Forward Transmission
The signal proceeds through the auditory system toward the brain in an efficient manner
Backward Transmission
When the signal reaches the cochlea, the active process generated by the outer hair cells cause a ripple that moves backward along the traveling wave
Where does the ripple go when it is transmitted back?
Through the ossicular chain in the middle ear and then converted to an acoustic signal by the TM
With a louder click will the emission be bigger?
Yes
What protein helps activate the OHC by expanding and contracting?
Prestin
What is the acoustic signal/emission that is backwards trasmitted?
0 to 20 db
What is the technology used to detect the backwards OAE in the ear canal?
The probe assemble is in the ear canal and contains a loudspeaker (tone generator) and a microphone
What does the microphone measure?
The low level acoustic emissions coming back from the cochlea and routes them to a computer for signal averaging
Transient OAE
OAE’s that use a click stimulus to stimulate a wide range of frequencies along the basilar membrane
How long to transient OAE’s occur?
4 msec after the onset of the stimulus and last about 10 msec
What are the frequencies presented for transient OAE’s?
1000 to 5000 Hz
Where are transient OAE’s absent?
Thresholds >30 dBHL (If greater than 30 bd then we know there are some OHC damage)
Distortion Product OAE
Evoked by presenting 2 tones simultaneously that interact on BM to produce a third tone
What is the formula for Distortion OAE
2F1-F2
What are the frequencies presented for distortion OAE’s?
1000 to 8000 Hz
Where are distortion OAE’s absent?
> 40 dB
What are OAE’s best use for?
Screening tool and part of the diagnostic test battery such as new born hearing screening, difficult to test patients, and suspect of functional HL. It is also good for monitoring changes in cochlear function such as otoxicity, progressive HL, and noise exposure
What is the limitation of OAE?
Won’t give you an actual threshold because you only know that thresholds are better than 30 or 40 dbhl for specific regions
If there is an absent OAE what is the problem?
ME or OHC problem (use tymp to see if ME is working- type a ohc problem and type b middle ear problem)
Is the elecrophysicolocial assessment an objective test?
Yes
What is electrophysiologic assessment?
Recording of electrical signals of cells