National Acoustic Laboratories, Sydney, Australia
New Perspectives in
Central Auditory
Processing Disorder
Sharon Cameron
Harvey Dillon
National Acoustic Laboratories
National Acoustic Laboratories, Sydney, Australia
OVERVIEW OF PRESENTATION
1.
New perspectives on CAPD
2.
Description of the LiSN-S
3.
Research behind LiSN-S
4.
LiSN-S and the traditional APD test battery
5.
How to interpret LiSN-S results
6.
Management options
7.
Description of LiSN & Learn Auditory Training Software
8.
LiSN & Learn Phase I and Phase II Clinicial Trial Results
9.
LiSN Screening Test – Sensitivity and Specificity Study
10.
LiSN-S “Prescribed Gain Amplifier” - HI Study 6-60+ Years
11.
Question time
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What is CAPD?
For children with (C)APD…..
“….. internal distortions degrade the auditory
signal so that top-down processing typically
predominates in most listening situations,
particularly those in which complex linguistic
and cognitive demands are coupled with
background noise”
Putter-Katz et al (2002)
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Operations Required for Comprehension of Speech in Noise
Wingfield, A and Tun, P (2007). J Am Acad Audiol 18:548–558
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Source Discrimination
aka Auditory Stream Segregation
5
1.
The ability of the brain to tease apart all the
sounds that arrive simultaneously at the ears and
to form meaningful representations of the
incoming acoustic information
2.
Auditory cues such as the location of the sound,
or the pitch of a speaker’s voice, help us to
segregating the total stream of sound into its
original sources
National Acoustic Laboratories, Sydney, Australia
LiSN-S Development
LiSN-S was developed specifically to
assess how children use:


Spatial location cues (ITD, IID)
Pitch differences between voices
to separate target auditory stimuli from
distracting auditory stimuli that arrive
simultaneously at the ears
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LiSN-S Research – Spatial Processing Disorder
Noise
Noise
Speech
Noise
Noise
7
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Description
1.
Adaptive speech-in-noise-test
2.
Target sentences - 0º azimuth initially at 62dB SPL
3.
Competing speech - 0º or ±90º azimuth at 55dB SPL
4.
3-D auditory environment under headphones
5.
Offers alternative to free-field testing
6.
No special hardware required
7.
Four LiSN-S conditions
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LISN-S Conditions
Low Cue SRT - SV0º
DV0°
Talker Advantage
Spatial Advantage
SV 90°
High Cue SRT – DV90º
°
9
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LiSN-S SRT & Advantage Measures
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Client Screen
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Configure Language
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Client Session
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Diagnostic Screen
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Results Screen
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Explanation Screen
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Client Assessment Report
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NA LiSN-S Sentence Equivalence Study
Pre-adjusted Sentences
1
0.9
Percent Correct
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
-3
-2
-1
0
1
Variation in dB from Estimated SRT
2
3
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NA LiSN-S Sentence Equivalence Study
Sentences Adjusted in dB for Equal Intelligibility
1
Percent Correct
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
-3
-2
-1
0
Variation in dB from Estimated SRT
1
2
3
National Acoustic Laboratories, Sydney, Australia
Australian LiSN-S Normative Data
202 participants:



106 children - 6 yrs, 2 mths to 17 yrs, 7 mths
60 young adults - 18 yrs, 1 mth to 29 yrs, 10 mths
36 older adults – 31 yrs, 8 mths to 60 yrs, 7 mths

English as a first language;

no history of hearing disorders;

no learning or attention disorders;

normal pure tone audiogram and middle ear function.
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Low Cue SRT
4
3
2
Better
1
0
-1
Low Cue SRT
vs Age Group
-2
p < 0.000001
Low Cue SRT (dB)
-3
-4
-5
-6
9
8
7
6
11
10
50-60
40-49
30-39
25-29
20-24
18-19
16-17
14-15
12-13
Age Group
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High Cue SRT
-10
-11
-12
Better
-13
-14
High Cue SRT vs.
Age Group
-15
p < 0.000001
-16
High Cue SRT (dB)
-17
-18
-19
-20
9
8
7
6
11
10
50-60
40-49
30-39
25-29
20-24
18-19
16-17
14-15
12-13
Age Group
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Talker Advantage
10
9
Talker Advantage vs.
Age Group
8
p < 0.000001
7
Better
6
5
4
2
1
0
9
8
7
6
11
10
Talker Advantage (dB)
3
50-60
40-49
30-39
25-29
20-24
18-19
16-17
14-15
12-13
Age Group
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Spatial Advantage
18
17
Spatial Advantage
vs Age Group
16
p = 00005
15
Better
14
13
12
10
9
8
9
8
7
6
11
10
Spatial Advantage (dB)
11
50-60
40-49
30-39
25-29
20-24
18-19
16-17
14-15
12-13
Age Group
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Total Advantage
18
17
Total Advantage vs
Age Group
16
p = 0.003
15
Better
14
13
12
10
9
8
9
8
7
6
Total Advantage (dB)
11
11
10
50-60
40-49
30-39
25-29
20-24
18-19
16-17
14-15
12-13
Age Group
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Conclusions

LiSN-S SRT scores show that the ability to understand speech
in noisy environments develops with age, is adult like by 14
years and starts to decline by 50 years of age.

LiSN-S advantage measures show that ability to use spatial
and pitch cues does not decline once adult-like performance is
reached.

The ability to use spatial cues matures well before the ability to
use pitch cues and thus plays a greater role in how well
children, in particular, are able to hear speech in noise.
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LiSN-S Cut-Off Scores
•
Level below which performance on a LiSN-S measure is considered
outside normal limits.
•
Two and three-part regression equations fitted to account for
improvement with age.
•
Low and High Cue SRT:

•
max (intercept + B-value * age, max (c, d + e * age) +
(2 * SDs of the residuals from the age-corrected trend lines)
Talker, Spatial and Total Advantage:

min (intercept + B-value * age, c) –
(2 * SDs of the residuals from the age-corrected trend lines)
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Cut-off Scores - Low Cue SRT
6
4
2
0
-2
-4
Low Cue SRT (dB)
-6
-8
-10
-12
0
10
20
30
40
Age
50
60
70
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Cut-off Scores - High Cue SRT
-6
-8
-10
-12
-14
-16
High Cue SRT (dB)
-18
-20
-22
-24
0
10
20
30
40
Age
50
60
70
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Cut-off Scores – Talker Advantage
16
14
12
10
8
6
4
Talker Advantage (dB)
2
0
-2
0
10
20
30
40
Age
50
60
70
National Acoustic Laboratories, Sydney, Australia
Cut-off Scores – Spatial Advantage
22
20
18
16
14
12
10
Spatial Advantage (dB)
8
6
4
0
10
20
30
40
Age
50
60
70
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Cut-off Scores – Total Advantage
22
20
18
16
14
12
Total Advantage (dB)
10
8
6
4
0
10
20
30
40
Age
50
60
70
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LiSN-S Test-Retest Reliability
•
85 participants recruited from NA LiSN-S normative data
studies.
•
Retested on LiSN-S between 1 and 4 months after initial
testing (average 2 months, 2 weeks).
•
Mean test-retest difference ranged from 0.05 dB to 0.5 dB.
•
RM ANOVA revealed no significant difference between test
and retest (p = 0.307 to 0.974, age categorical variable).
•
Correlation between test and retest significant for all
measures (p = 0.006 to <0.00001; r ranged from 0.3 to 0.6)
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Spatial Advantage
Current effect: F(12, 72)=.81714, p=.63220
16
15
14
13
12
11
10
9
Spatial Advantage (dB)
8
7
6
5
6
7
8
9
10
11
12
13
Age Group
14
15
16
17 Adult
Test
Retest
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NA LiSN-S Critical Difference Scores
Correction Factor
(Mean Test-Retest
Difference)
SD of the
Mean TestRetest
Difference
1.64 x
SD
Critical
Difference
(Including
Correction)
dB
dB
dB
dB
Low-Cue SRT
-0.49
1.51
2.47
-3.0
High-Cue SRT
-0.44
2.40
3.93
-4.4
Talker Advantage
0.31
2.46
4.03
4.3
Spatial Advantage
-0.05
2.21
3.63
3.6
Total Advantage
0.06
2.35
3.85
3.9
Condition
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Australian LiSN-S APD Study

Nine children aged 6 to 11 years experiencing listening
difficulties in class relative to peers who had no learning
or attention disorder (SusAPD group).

Eleven children with confirmed learning or attention
disorders (LD group).

Assessed on LISN-S and results compared to 70 agematched controls.

Assessed with a traditional (C)APD test battery
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LiSN-S vs. Traditional Battery (LD Group)
LD Group
4
2
0
-2
-4
-6
-8
-10
Min-Max
Total Adv
Spatial Adv
25%-75%
Talker Adv
HC SNR
LC SNR
MLD
RGDT
DD (LE)
DD (RE)
-12
PPS (LE)
Median
PPS (RE)
Deviation from Mean Normal Performance
6
Cameron & Dillon (2008)
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LiSN-S vs. Traditional Battery – SusAPD Group
SusCAPD Group
4
2
0
-2
-4
-6
-8
-10
Total Adv
Spatial Adv
Talker Adv
HC SNR
LC SNR
MLD
RGDT
DD (LE)
Min-Max
DD (RE)
25%-75%
PPS (LE)
Median
-12
PPS (RE)
Deviation from Mean Normal Performance
6
Cameron & Dillon (2008)
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Better
Low Cue SRT
(LD)
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Better
Spatial Advantage
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LiSN-S Results – Normal
Male, 11 years, 10 months showing Normal Performance
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LiSN-S Results - SPD
Male, 7 years, 5 months with Spatial Processing Deficit
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LiSN-S Results – Memory Deficit
Male, 8 years, 3 months with Memory Deficit
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LiSN-S Results – Attention Issues
Female, 7 years, 10 months with Attention Issues
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Managing Spatial Hearing Deficits
1.
Teacher-directed strategies
2.
Child-directed strategies
3.
Language training
4.
Classroom modification (+10 dB SNR)
5.
Assistive listening device
6.
Training in source discrimination
National Acoustic Laboratories, Sydney, Australia
Auditory Training Research

Develop deficit-specific remediation for children with a spatial
processing deficit.

Trains children to use binaural cues – i.e. differences in the timing
and intensity of signals arriving at the ears from various locations to attend to a target stimulus and filter distracting auditory signals.

Used in the home (as well as schools/clinics).

Provides detailed analysis, reporting and feedback.

Alternative/adjunct to ALD’s and other management strategies.
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Description of LISN & Learn

Four games presented on PC over headphones

Target sentences at 0º azimuth (initially 62 dB SPL)

Competing stories at ±90º azimuth (55 dB SPL)

Weighted up-down adaptive procedure used to
adjust the signal level of the target

SRT calculated over 40 sentences

131,220 unique sentences can be generated
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LISN & Learn Game
Target at 0˚:
The horse kicked
six wet shoes
Distracters at + and -90˚:
Tamsin’s Blanket (-90˚)
Eric’s Alarm Clock (+90˚)
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Target: The horse kicked six wet shoes
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Method

9 children (6 to 11 years) - LISN-S SA >2SD

TOVA-A

TAPS-3 memory sub-tests

CAPD Pediatric SSQ

LISN & Learn - 15 minutes per day; 5 days per
week; over 12 weeks (120 games)

Re-evaluate post-training; 3 months post-training
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LiSN & Learn SRT (dB)
Better
LiSN & Learn - Performance Over Time (n=9)
10 dB
Game Number
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LiSN-S Results – Pre vs. Post (n=9)
LiSN-S Score
(Population Standard Deviation Units)
2
1
0
LC SRT -
p = 0.158
Talker Advantage - p = 0.981
-1
HC SRT -
p = 0.0002
Spatial Advantage - p = 0.0002
Total Advantage -
-2
-3
Pre-Training
Post-Training
3M Post-Training
-4
LC SRT
HC SRT
Talker
LiSN-S Condition
Spatial
Total
p = 0.001
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Additional Results – Pre- vs. Post Training

CAPD SSQ:



TOVA-A



Listening in Quiet – p = 0.103
Listening in Noise – p = 0.0002
Omissions – p = 0.168
Commissions – p = 0.0004
TAPS-3

Memory Index – p = 0.003
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Conclusion

LiSN & Learn training has the potential to
strengthen or reorganize connections
dedicated to binaural processing.

Training results in enhanced ability to
process speech in background noise.
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Method – Phase II Clinical Study
1.
20 children - LISN-S spatial advantage >2SD from mean
a)
b)
2.
10 x LiSN & Learn (experimental group)
10 x Earobics (control group)
Questionnaire
a)
b)
c)
Participant (LIFE)
Parent (Fishers)
Teacher (LIFE)
3.
LiSN & Learn or Earobics training – 15 minutes per day
4.
Re-evaluate LiSN-S and questionnaires post-training
5.
Offer LiSN & Learn to control group.
56
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Phase II Study - LiSN & Learn Group (n=1)
2
1.5
SD from Mean
1
0.5
0
-0.5
-1
-1.5
-2
-2.5
-3
-3.5
Low Cue SRT
High Cue SRT
Pre-training
Post-training
Talker Adv
Spatial Adv
Total Adv
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Phase II Study - Earobics Group (n=1)
2
1.5
SD from Mean
1
0.5
0
-0.5
-1
-1.5
-2
-2.5
-3
-3.5
Low Cue SRT
High Cue SRT
Pre-training
Post-training
Talker Adv
Spatial Adv
Total Adv
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LiSN-S Screening Test

Develop screening test to be used by teachers, speech pathologist,
psychologists.

Fully-automated instructional, testing, scoring and reporting functions.

Accessible via internet.

End-users own computer and headphones used.

Aims to:


Decrease time taken to refer children (and adults) with suspected CAPD for diagnostic
testing with LiSN-S.

Reduce inappropriate referrals.
Reduced referral time will result in speedier implementation of management
and remediation programs for those with SPD.
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LiSN Screening Test
Client data
1. End-user inputs client data
Sound check
1. Sets output level of computer soundcard
2. Reference tone consists of “pulsed”
speech-shaped broadband noise
3. Reference tone is presented at 40 dB
below level of combined distracters
4. Listener adjusts volume control until he
or she can “just hear” the reference tone
5. Assumed to be at least 10 dB SPL
6. Therefore level of distracters presented
during test is approx 50 dB SPL
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LiSN Screening Test
Word familiarization task (in quiet)
1.
3 target words (red, blue, green)
2.
12 “foils” (e.g. hat, doll, milk)
3.
Listener clicks on picture that matches word
until all words correctly identified.
LiSN Screening Test
1.
Distracters – looped stories (DV +/- 90º)
2.
Targets and foils:
•
•
•
Female 1 at 0º
initially presented at SNR of +4 dB
2 second ISI
4.
Listener clicks mouse when target heard.
5.
Adaptive procedure used to find SRT that
yields 50% intelligibility.
6.
Level of word stimuli adjusted in 3 dB steps.
7.
At least 6 targets presented as practice.
8.
SRT calculated over up to 40 scored targets
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LiSN-S Screening Test Studies
1.
2.
Target Stimulus Equalization Study
a)
30 adults aged 18 to 29 years
b)
SRT of scored target words (red, blue, green) consolidated across
participants and psychometric functions formulated
c)
Amplitude of target words adjusted for equal intelligibility
Sensitivity and Specificity Study
a)
40 children and adults with suspected CAPD
b)
Tested with LiSN Screening Test at referring centre
c)
Tested with LiSN-S no more than 3 weeks later at NAL
d)
Correlation between LiSN Screening Test and LiSN-S determined
e)
ROC analysis used to determine sensitivity and specificity
f)
Optimum criteria cut-off scores determined
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LiSN-S Prescribed Gain Amplifier
National Acoustic Laboratories, Sydney, Australia
CAPD and Hearing Impairment Studies
1.
LiSN-S Study
a)
b)
c)
160 participants (40 x 6-17; 20 x 18-29; 20 x 30-59; 80 x 60+)
Confirmed mild-to-moderately-severe SNHL (3FAHL of 65 dB)
Assessment gools:
•
•
•
•
2.
LiSN-S + PGA
LIFE Questionnaire (6-17 years)
SSQ Questionnaire (18-60+ years)
COGNISTAT (60+ years)
“LiSN & Learn” Study
a)
b)
c)
60 participants (10 x 6-17; 10 x 18-60; 10 x 60+)
Confirmed mild-to-moderately-severe SNHL (3FAHL of 65 dB)
Assessment tools:
•
•
•
•
d)
LiSN-S + PGA
Memory Test
LIFE Questionnaire (6-17 years)
SSQ Questionnaire (18-60+ years)
“LiSN & Learn” + PGA (120 games) then re-assess
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References

Brown, D., Cameron, S. Martin, J., Watson, C., & Dillon, H. (in press). The North American Listening in
Spatialized Noise – Sentences Test (NA LiSN-S): Normative data and test-retest reliability studies for
adolescents and young adults.

Cameron ,S., Brown, D., Keith, R., Martin, J., Watson, C., & Dillon, H. (2009). Development of the North
American Listening in Spatialized Noise - Sentences Test (NA LISN-S): Sentence equivalence,
normative data and test-retest reliability studies. Journal of the American Academy of Audiology, 20(2),
128-146.

Cameron, S. & Dillon H. (2009) Listening in Spatialized Noise – Sentences test (LISN-S) (Version 1.013)
[Computer software]. Murten, Switzerland: Phonak Communications AG.

Cameron, S. & Dillon, H. (2008). The Listening in Spatialized Noise – Sentences Test: Comparison to
prototype LISN test and results from children with either a suspected (central) auditory processing
disorder of a confirmed language disorder. Journal of the American Academy of Audiology, 19(5), 377391.

Cameron, S. & Dillon, H. (2008). Spatial hearing deficits as a major cause of auditory processing
disorders: Diagnosis with the LISN-S and management options. In R. Seewald & J. Bamford, eds. A
Sound Foundation Through Early Amplification 2007. Proceedings of the Fourth International
Conference: Phonak AG, Switzerland, 235-241.

Cameron, S. & Dillon, H. (2007). Development of the Listening in Spatialized Noise - Sentences Test
(LISN-S). Ear and Hearing, 28(2), 196-211.

Cameron, S. & Dillon, H. (2007). The Listening in Spatialized Noise - Sentences Test (LISN-S): Testretest reliability study. International Journal of Audiology, 46, 145-153.
National Acoustic Laboratories, Sydney, Australia
Acknowledgements and Q&A

Dr Harvey Dillon
Director of Research
National Acoustic Laboratories

Helen Glyde
Research Audiologist
National Acoustic Laboratories