w3 - Ax of APD (scope of practice & screening) Flashcards
Who is an audiologist that works primarily with APD?
Dr. Angela Alexander
What is the hierarchy of hearing a sound?
1) Awareness: problem with this could mean HL (overcome awareness with Has) - ear
2) Discrimination: know that /b/ and /d/ are different - brain
3) Identification: know that /b/ means “b” and /d/ means “d” - brain
4) Comprehension: understanding what is being said - brain
With APD, issues can occur at any level of the hierarchy
What is CAP?
refers to the perceptual processing of auditory information in the central nervous system
CAP encompasses auditory mechanisms responsible for what 5 things?
1) speech and non-speech discrimination
2) sound localization
3) auditory pattern recognition
4)temporal aspects of hearing
5) performance with degraded or competing sounds
APD Ax are based on these components
What is APD?
APD is characterized by difficulty in auditory processing in one or more of the auditory-related skills listen above
What is bottom up processing?
- Bottom-up: a disorder of the auditory pathway that is affecting other aspects.
- auditory-driven hypothesis says APD is a difficulty in BUP
What is top down processing?
- Top-down: a cognitive disorder that affects auditory processing (a holistic view taking into account memory and executive functioning).
- cognitive-driven hypothesis says APD is a difficulty in TDP
APD Ax vs Dx
Ax: the process of collecting data regarding functional areas of strength and weakness
Dx: identifying and labeling/categorizing a specific impairment or dysfunction
APD Ax requires a ____
multidisciplinary team (audiologists, SLPs, psychologists, teachers, and paretns)
APD Dx is the responsibility of a ____
trained audiologist
What is the role of an SLP in APD?
- they collaborate with audiologists in the assessment (cognitive, speech, and language abilities) treatment of APD
- to identify and provide services for associated comorbidities
What are the 3 types of stimulus presentation?
1) monaural (monotic) presentation
2) dichotic presentation
3) diotic presentation
What is monaural/monotic presentation?
auditory stimuli are presented to only one ear (mostly used with SIN Ax)
What is dichotic presentation?
Auditory stimuli are presented to both ears simultaneously, with the stimulus presented to each ear being different (the 2 ears are receiving 2 different types of stimuli at the same time)
What is diotic presentation?
This term stands in contrast to dichotic, in which identical stimulus is presented to both ears simultaneously (both ears are receiving the same stimuli)
What are the 2 objectives for APD screening?
1) early identification of individuals at risk for CAPD
2) offering full diagnostic assessment and treatment if needed
Why are those with history of chronic OME at risk for APD?
This causes APD is because the brain is learning language and speech through a distorted signal (maladaptive brain plasticity)
Is there a universally accepted method for APD screening?
No
APD screening can involve what 4 things?
a) case hx, behavioural checklist, functional observations
b) parent/teacher questionnaires
c) specific screening test batteries (SCAN)
d) using a single APD test as a screening tool (DDT)
What are 4 common APD checklists and questionnaires?
- CHAPS (children’s auditory performance scale)
- Fisher auditory processing checklist
- SIFTER (the screening instrument for targeting educational risk)
- CHILD (children’s home inventory for listening difficulties)
What is the aim of CHAPS?
to judge whether or not a child has more difficulty than other children in each listening condition
CHAPS test structure
- 6 listening conditions
- 36 questions with 7 likert choices
CHAPS score interpretation
- pass range: +36 to -11
- at risk range: -12 to -130
What did research on CHAPS find?
- 45% required no special support services (over-referral or false positive)
- 55% required some type of special support or academic accommodations (sensitivity)
- 50% had below-grade-level reading ability
Overall, is CHAPS a good checklist?
- one of the most known checklists for identifying those at risk for APD
- however, has more complications (not a reliable test of APD screen, can use this + a diagnostic test)
- audiologists like this questionnaire because it looks at the amplification side of things evaluating performance in different environments
What is a great checklist for an APD screen?
- CHILD
- developed by audiologists
- covers all aspects of listening with APD
What are 2 types of objective APD screening tests?
a) SCAN
- SCAN 3:A (adult)
- SCAN 3:C (children)
b) differential screening test of processing (DSTP)
What is the SCAN?
SCAN: the screening test for auditory disorders
- an objective Ax that assess all areas of APD
What 4 screening tests does the SCAN use?
1) gap detection
2) auditory figure ground
3) competing words : free recall
4) filtered words test
What age is SCAN 3:A and C for?
SCAN 3C (5:0 - 12:11)
scan 3A (13:0 - 50:11)
How long does the SCAN take?
screening time = 10-15 min
diagnostic time = 30-45 min
What ages is DSTP for?
6:0 to < 12 years
How long does the DSTP take?
35 min
What are the 3 subtests of the DSTP?
1) level 1 (acoustic subtests)
- a) dichotic digit test (binaural integration skills)
- b) temporal pattern test (sequences of high and low soudns)
- c) auditory discrimination test (nonsense syllables presented in background noise)
2) level 2 (acoustic linguistic subtests)
- d) phonemic manipulation test (recognizing the number of discrete sounds in words, blending discrete phonemes into a word, and changing or modifying specific discrete phonemes)
- e) phonic manipulation test (three tasks of sound-symbol associations)
3) level 3 (linguistic subtests)
- f) antonyms
- g) prosodic interpretation
- h) language organization (the student hears clues and uses them to generate a response)
In the DSTP, what does poor performance in 1 or more subtests indicate?
Need for diagnostic referral
What do audiologists think of the DSTP (3)?
- not as popular as the SCAN (more of a linguistic test created by SLPS, very language based)
- smaller age range
- less studied with limited psychometric properties reported
When using a diagnostic test for an APD screening, what 3 choices do you have?
1) SIN tests
2) dichotic tests
3) frequency pattern sequences test (FPST)
What are 3 examples of SIN tests?
1) Quick SIN
2) BKB SIN
3) WIN
In all tests, the noise (multi-talker babble noise) level is fixed, and the speech level varies
What is an example of a dichotic test?
- DDT: a test of binaural integration, binaural separation, and interhemispheric transfer
- a test with little linguistic load
- relatively resistant to cochlear dysfunction (peripheral HL)
What do frequency pattern sequences tests test (3)?
a test of frequency discrimination, temporal ordering, and acoustic labelling
Quick SIN
a) purpose
b) age
c) presentation
a) to evaluate a persons ability to understand speech in background noise
b) adults
c) monaural, typically using headphones
Quick SIN - test structure
- consists of 6 sentences (each list holds 5 target words)
- SNRs range from +25 dB (easy) to -10 dB (difficult)
Quick SIN - scoring method
- lists are scored based on the number of correctly identified keywords
- based on the SNR 50 (the SNR at which the person achieves 50% speech intelligibility across all 6 lists)
Quick SIN - SNR loss 0-3dB
- normal/near normal
- may hear better than normal peers in noise
Quick SIN - SNR loss 3-7 dB
- mild SNR loss
- may hear similar to normal peers in noise
Quick SIN - SNR loss 7-15 dB
- moderate SNR loss
- requiring directional microphone
Quick SIN - SNR loss >15 dB
- severe SNR loss
- requiring maximum SNR
- use of FM system
What is the QuickSIN cutoff for needing a full APD eval?
- those identified with mild SNR should be sent for a full eval (3-7 dB)
BKB SIN
a) purpose
b) age
c) presentation
a) provides materials for listeners for whom the quickSIN is too challenging
b) 5+
c) monaural
BKB SIN - test structure
- includes short sentences preceded by the verbal cue “ready”
- consists of 18 pairs composed of 20 sentences spoken by a male talker
- SNR varies with sentences (+21 to -6 dB SNR)
BKB SIN - scoring method
- lists are scored based on the number of correctly identified keywords
- based on the SNR 50
WIN
a) purpose
b) age
c) presentation
a) to evaluate the ability of listeners to understand words in noise
b) commonly used for identifying those at risk for APD in older adults
c) monaural
WIN - test structure
- including 70 words spoken by a female speaker
- consisting of 10 words in 7 SNR levels from 24 to 0 in 4dB increments
WIN - scoring method
- lists are scored based on the number of correctly identified words
- based on the SNR 50
What is the NIH toolbox?
A combination of SIN tests for assessing APD
DDT - age
> 7 years old
DDT - test structure
- composed of naturally spoken digits from 1 to 10 (excluding 7)
- includes 20 digit pairs for a total of 40 test items per ear
- tow different digits are presented to each ear simultaneously
DDT - test instruction
you will hear 2 numbers in each ear. listen carefully in both ears and repeat all the numbers you hear in any order. if you are not sure about the number you heard, please guess.
What stimulus level (dB SL) is the DDT completed at?
earphones at 50 dB SL (at a comfortable level)
DDT - scoring method
each ear score is compared with age appropriate norms
Explain the DDT scoring (why are results in the RE better, why do we expect the same scores for both ears after age 12)
These are the cut off scores
- Ex) Score below 55% in the L and below 70% in the R = abnormal
- 95% get better results in the R compared to the L (right ear advantage)
- Greater than 12 years we expect the same scores for both ears (corpus callosum maturing); below 12, the CC is NOT mature enough to give the same score
FPT
a) aim
b) age
c) presentation
a) to assess the ability for frequency/pitch discrimination
b) < 8 years
c) monaural under headphones in a quiet testing environment
FPT - stimuli
- a series of tone stimuli with varying patterns (2 frequencies x 3 presentations = 6 different patterns)
- this person is instructed to respond verbally or manually
FPT scoring and interpretation
- the percentage of correctly identified frequency patterns
- the results are compared with age appropriate normative data
What is a great resource of APD screening and diagnostic tests?
Auditec Inc
