S516 FInal
Differential diagnosis for normal hearing
Normal hearing • What relationships between speech scores and pure-tone thresholds? • SRT ± 7 dB = PTA • 88% or higher on 25-word list at 30 dB SL • No rollover (decline in PI as intensity increases) • UCL - SRT = 80-100 dB
speech audiometry
Performance intensity functions • Compares word and speech intelligibility scores across different intensities rollover happens bc of imparied differential sensitivity and indicates retrocochlear pathology
presentation mode
Pre-recorded vs monitored live voice (MLV) Response format: Open-set format vs Closed-set format signal-to noise ratio (SNR) and type of noise
QuickSIN administration
Present at 70 dB HL if PTA 45 dB or less Otherwise, set to "loud but ok" level Credit given for each correct keyword 30 words total (5 words, 6 sentences) SNR decrease with each sentence SNR loss = 25.5 - Correct Keywords = SNR for 50% correct, with NH correction Use 2 or 3 lists per ear/condition
differential diagnosis for retrocochlear hearing loss
Retrocochlear hearing loss • What relationships between speech scores and pure-tone thresholds? • SRT ± 7 dB = PTA • Reduced WRS lower than predicted by PTA • rollover (decline in PI as intensity increases) on affected (VII nerve) or also on opposite side (central) • UCL - SRT = 80-100 dB
rollover
Rollover occurs when the speech recognition score decreases more than 20% from the maximum performance (PB-max) obtained at a lower intensity level. This is consistent with retrocochlearpathology tested unilaterally
differential diagnosis for SN hearing loss
Sensorineural hearing loss • What relationships between speech scores and pure-tone thresholds? • SRT ± 7 dB = PTA • Reduced WRS predictable by PTA • No rollover (decline in PI as intensity increases) • UCL - SRT = 30-50 dB
which loudness percept tests should we do for HA
UCL and LCL
suprathreshold adaptation test (STAT)
abnormal adaptation (fatigue) occurs first at high intensities for retrocochlear losses
motivating factors for pseudohypocusis
adults: financial gain, special attention children: failed hearing screening, poor academic achievement, emotional support
SNR loss may be affected by
age ear cochlear dead regions working memory capacity musical training
site of lesion tests
black dots tell us pattern that corresponds to site of lesion
WRS process and masking
calibrate VU meter to 0 present word list (via CD) at 40 dB above SRT likely will have to mask, but check anyway... masking level should be 30 dB below (-40 + 10)
how should an audiologist handle pseudohypoacusis?
clinicians must be alert to presence of this "pathology" -identify clues -use tests to support or deny suspicions -ascertain actual hearing status, if possible -assist in managing the patient
test battery
collection of tests that usually assess a variety of different attributes varies depending on needs of assessment
SDT Clinical Chart
condition present vs absent positive (have disorder) vs. negative (don't have) positive + condition present = correct ID of condition (true +) negative + condition present = incorrect ID of normal condition (false -) positive + condition absent = incorrect ID of abnormal condition (false +) negative + condition absent = correct ID of normal condition (true -)
factors for asymmetry
confidence in scores obtained large vs. small range of confidence interval can use SPRINT chart to determine if difference is significant not as useful if bilateral retrocochlear pathology
what does SNR loss tell us that pure-tone audiograms do not?
degree of difficulty experienced when listening to speech in noise
audibility
did you hear- y or n
what does SNR loss compare?
difference in dB SNR compared to normative data is termed the "SNR loss" -deviation from performance by NH on a given test SNR at which an individual with hearing impairment understands 50% of sentences (speech material) & SNR at which a normal-hearing person can understand 50% of sentences
Quick Speech in Noise (QuickSIN) Test
each list takes about one minute 12 lists (plus practice lists) recorded on a CD
earphones vs. soundfield
earphones- calibration/standardization easier individual ear info and can mask soundfield- can use as baseline for aided verification
what type of masking does QuickSIN use?
energetic and informational
types of masking
energetic, noise masking signal information masking, interference from linguistic content
speech in noise testing during HA fits does what?
establishes a baseline and monitors performance over time assists with counseling helps patient to make a decision
Pseudohypoacusis
false hearing loss patient responds behaviorally only when stimuli are presented at levels well above true thresholds admitted thresholds are elevated and exaggerated other terms include: simulated loss and malingering
details of speech range
has short term fluctuations, but isn't random
differential sensitivity
how auditory system processes ability to detect changes in intensity, frequency, and temporal aspects of the signal, all of which are potential cues for speech recognition."
dynamic range of speech
in amos, its 300 to 3000
test battery approaches
lax: positive if fails 1 of 3 tests strict: positive if they fail 3 tests
varying levels of speech by vocal effort
loud speech is 85 dB SPL (65 dB HL), typical loudness is 65 dB SPL (45 dB HL) and faint speech is 45 dB SPL (25 dB HL)" *audiometric threshold is reference
loudness balancing (ABLB)
measures recruitment
Short increment sensitivity test (SISI)
measures recruitment through change in tones
Long Term Average Speech Spectrum (LTASS)
more energy at low Hz from amos: 30 dB range, 12 up and 18 below used for HA
critical differences between conditions
more lists gives us more accuracy and we want 95% confidence
band importance
more weightings on certain Hz than others
Does the entire speech signal need to be audible for maximum speech recognition?
no
can we use all QuickSIN lists?
no, not all lists are equivalent
Gaussian Noise
noise that contains every frequency at equal amplitude and random phase
Selection of stimuli material
nonsense syllables, words, sentences/phrases, paragraph advantages and disadvantages for both
SNR loss related to degree
normal hearing=0-3 dB mild SNR loss= 3-7 dB moderate SNR loss= 7-15 dB severe SNR loss= > 15 dB
additional tests for pseudohypocusis
only ones we use here are ABR, reflexes, and OAE
bekesy audiometry
pt records their own audiometric levels used in armed forces patterns associated with pathology
threshold tone decay
quantifies amount of auditory fatigue when stimuli are presented at or near sensitivity threshold based on the idea that loudness of a tone decays over time... rapid decay consistent with retrocochlear and slow associated with cochlear
results of speech in noise testing
selection of the fitting arrangement hearing aid style and/or the need for speech features
Sensitivity vs. Specificity
sensitivity - how well a test identifies truly ill people (SNOUT - rules OUT) specificity - how well a test identifies truly well people (SPIN - rules IN)
count-the-dot
similar to AI but predicts different errors
SRT process and masking
start with unmasked SRT familiarization: Present at least 12 spondees at 30 to 40 dB above expected threshold or at a comfortable listening level down 10 for every correct until miss 2 then up 5 until they get 2 is masking needed? compare R and L ears then to BC of NTE if masking is needed-presentation - 40 dB + 10 dB present 2 words, if pt gets both correct you're good
Cross-Check Principle (Jerger, 1976)
the results of a single test are crosschecked by an independent test measure if you miss a disorder, pt won't get treated if you incorrectly diagnose, pt will waste time and money
why is speech in noise testing important for HA fits?
understanding speech in noise is likely the reason patient is seeking hearing help
how does pseudohypocasis present in the clinic?
variety of forms: unilateral, bilateral, mild in degree through profound, in children and adults difficult to determine whether conscious or unconscious
testing for pseudohypocusis
variety of tests devised to detect/reveal inaccuracy of admitted thresholds
importance of sensitivity and specificity
want both to be high
clinical signs of pseudohypocusis
• Poor test-retest reliability • SRT and PTA disagreement • Bone conduction loss bigger than IA • Failure to demonstrate shadow curve • Lack of false positives
spectrum
Amplitude Spectrum - Amplitude as a function of frequency • Phase Spectrum - Phase as a function of frequency
audiometry calibration
Calibration should be administered for CD (any recorded materials) as well as for talkback system. Different calibration for speech: 0 dB HL for speech (earphone) = 20 dB SPL
recruitment
Change in loudness is greater in the presence of cochlear hearing loss for a given change in intensity abnormal growth of loudness in SNHL
specific characteristics of speech in noise tests
Earphones or soundfield? Where to position patient/speaker(s)? What is the speech material and noise type? Noise mixed or separate? (ch 1 vs ch 2) How to calibrate? How to score? -Every word? Some of the words? Does the word have to be precisely repeated? What instructions do you give? Are all word/sentence lists equal? Are all word/sentence lists normed? How to interpret? What kind of score does the test give? How many items/lists are needed? How long does it take to administer? Adaptive vs. fixed SNR? Good for kids/adults/older adults/low cognitive ability?
Clinical applications of AI/SII framework
Estimate audibility of speech testing materials- based on average word lists • As a counseling tool -With audiogram -With REM • Hearing aid fittings SII predicts how someone hears in quiet
effects of masking
HA benefit poorest when background signal contains energetic and information masking
QuickSin
Speech in Noise test. Repeat sentences spoken by target talker. 5 key words in each sentence.
Word familiarity:
The target words should be within listeners' vocabularies. Speech material for adults cannot be used for children. One time of familiarization even can increase 3-4 dB
speech testing
WRS is a % correct-> suprathreshold SRT is a threshold for speech recognition
using signal detection theory, consider why we screen at 30 dB HL rather than 0 dB HL
at 0 dB, we'd refer so many more people we also don't want to miss anyone with HL so we keep it low
what Hz contribute to SRT and WRS
high Hz for WRS- monosyllabic low Hz for SRT- spondees
Are all speech frequencies equally important to speech recognition?
if you filter out certain Hz, it will have more of an affect than others
speech recognition threshold
the lowest intensity at which speech can barely be heard present 30-40 dB above threshold
noise waveform
time on x by amp on y
how do we express sound pressure level or sound intensity level for noise?
total power within bandwidth overall dB SPL [total power] = spectrum level (dB) + 10 log (bandwidth)
what is required for MLV speech audiometry?
two-room test suite *pre-recorded speech material is fine in one-room
expected SRT score
± 6 dB from PTA or 500/1000 Hz
Loudness perception
• MCL - most comfortable listening level (right in dynamic range) -typically ~40 dB above SRT in normal hearing • UCL - uncomfortable loudness level; level beyond which the sound be painful and intolerable -Typically determined using running speech -Presentation begins 20 dB above SRT and is typically ~100 dB above SRT (normal hearing) -Patient asked to judge loudness (cannot take any louder noise) • LDL - loudness discomfort level -below UCL so testing is not so uncomfortable
clinical decision analysis
"systematic approach to decision making under conditions of uncertainty" (from packet, p. 49, citing Turner & Nielson 1984) Decisions: -nature of auditory disorder -Management -Significance of certain texts -within context of a test battery
variables of speech audiometry
(1) Room (2) Calibration (3) Presentation mode (4) Response format (5) SNR and type of noise (6) Number of items (7) Familiarity to stimuli material (8) Selection of stimuli material
speech audiometry-rationale
-Performance intensity functions -Compares word and speech intelligibility scores across different intensities we can get specific information about a pt's speech understanding... can differ even in patients with identical audiograms
speech testing and retrocochlear pathology
2 indicators of retrocochlear pathology during speech testing: 1) rollover 2)asymmetry- most retrocochlear is unilateral more evident with suprathreshold testing (WRS)
Theory of Signal Detection
A theoretical approach for separating sensory capability from response proclivity conservative= fewer hits and misses vs. more responses and misses
adaptive vs fixed SNR
Adaptive: Either speech or noise is fixed and the other is varied Fixed: SNR is the same for all presentations
differential diagnosis for conductive hearing loss
Conductive hearing loss • What relationships between speech scores and pure-tone thresholds? • SRT ± 7 dB = PTA • 88% or higher on 25-word list at 30 dB SL • No rollover (decline in PI as intensity increases) • UCL - SRT = 80-100 dB
adding noise to standard word lists
DON'T DO IT standard lists do not continue to be equivalent if you add your own noise
Number of items (Half vs Full list presentation)
Fewer items = greater variability for 50% correct score. we want 95% confidence, so more in a list give us more accuracy
performance intensity function
Graph of percentage-correct speech recognition scores plotted as a function of presentation level of the target signals. compare config and max level a conductive would be normal, but shifted SNHL- wouldn't reach 100 for max and shifted
Audibility or Speech Inventory Index (AI/SII)
Hz weighting can be used to predict amount of speech audible band importance- 2000 Hz is more important range for speech intelligibility (WRS)
speechmap
LTASS with speech peaks and valleys
Prevalence of condition/disease and accuracy
Lower disease prevalence = lower chance of correct identification with a positive test result [highly specific] In many cases, we seek to "rule out" a disorder severe disorders = needs immediate attention [high sensitive]
3 factors for quantifying speech acoustics
-level at each Hz and overall level for various vocal effort levels (soft, casual, raised, shouted) -dynamic range for a single vocal effort level (range of levels from lowest to highest portions of speech at specified Hz) -level change over time (sometimes described by modulation rate and modulation depth)