New Perspectives in Central Auditory Processing Disorder

1
New Perspectives in Central Auditory Processing
Disorder

• Sharon Cameron
• Harvey Dillon
• National Acoustic Laboratories

2
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

3
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)

4
Operations Required for Comprehension of Speech
in Noise
Wingfield, A and Tun, P (2007). J Am Acad Audiol
18548558
5
Source Discrimination aka Auditory Stream
Segregation

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 speakers voice, help us to
   segregating the total stream of sound into its
   original sources

6
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

7
LiSN-S Research Spatial Processing Disorder
Noise
Noise
Speech
Noise
Noise
8
Description

• Adaptive speech-in-noise-test
• Target sentences - 0º azimuth initially at 62dB
  SPL
• Competing speech - 0º or 90º azimuth at 55dB SPL
• 3-D auditory environment under headphones
• Offers alternative to free-field testing
• No special hardware required
• Four LiSN-S conditions

9
LISN-S Conditions
10
LiSN-S SRT Advantage Measures
11
Client Screen
12
Configure Language
13
Client Session
14
Diagnostic Screen
15
Results Screen
16
Explanation Screen
17
Client Assessment Report
18
NA LiSN-S Sentence Equivalence Study
19
NA LiSN-S Sentence Equivalence Study
20
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.

21
Low Cue SRT
Better
Low Cue SRT vs Age Group p lt 0.000001
22
High Cue SRT
Better
High Cue SRT vs. Age Group p lt 0.000001
23
Talker Advantage
Talker Advantage vs. Age Group p lt 0.000001
Better
24
Spatial Advantage
Spatial Advantage vs Age Group p 00005
Better
25
Total Advantage
Total Advantage vs Age Group p 0.003
Better
26
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.

27
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)

28
Cut-off Scores - Low Cue SRT
29
Cut-off Scores - High Cue SRT
30
Cut-off Scores Talker Advantage
31
Cut-off Scores Spatial Advantage
32
Cut-off Scores Total Advantage
33
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 lt0.00001 r
  ranged from 0.3 to 0.6)

34
Spatial Advantage
35
NA LiSN-S Critical Difference Scores
Condition Correction Factor (Mean Test-Retest Difference) SD of the Mean Test-Retest Difference  1.64 x SD Critical Difference (Including Correction)
Condition Correction Factor (Mean Test-Retest Difference) SD of the Mean Test-Retest 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
36
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
  age-matched controls.
• Assessed with a traditional (C)APD test battery

37
LiSN-S vs. Traditional Battery (LD Group)
Cameron Dillon (2008)
38
LiSN-S vs. Traditional Battery SusAPD Group
Cameron Dillon (2008)
39
Low Cue SRT
Better
(LD)
40
Spatial Advantage
Better
41
LiSN-S Results Normal
Male, 11 years, 10 months showing Normal
Performance
42
LiSN-S Results - SPD
Male, 7 years, 5 months with Spatial Processing
Deficit
43
LiSN-S Results Memory Deficit
Male, 8 years, 3 months with Memory Deficit
44
LiSN-S Results Attention Issues
Female, 7 years, 10 months with Attention Issues
45
Goal of Management Strategies

• The ultimate goal of CAPD management in children
  is to maximize the auditory learning abilities
  so that communication and classroom learning
  experiences are more successful
• Putter-Katz et al (2002)

46
Managing Spatial Hearing Deficits

• Teacher-directed strategies
• Child-directed strategies
• Language training
• Classroom modification (10 dB SNR)
• Assistive listening device
• Training in source discrimination

47
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 ALDs and other management
  strategies.

48
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

49
LISN Learn Game
Target at 0
The horse kicked six wet shoes
Distracters at and -90
Tamsins Blanket (-90) Erics Alarm Clock (90)
50
Target The horse kicked six wet shoes
51
Method

• 9 children (6 to 11 years) - LISN-S SA gt2SD
• 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

52
LiSN Learn - Performance Over Time (n9)
Better
10 dB
LiSN Learn SRT (dB)
Game Number
53
LiSN-S Results Pre vs. Post (n9)
LC SRT - p 0.158 Talker Advantage
- p 0.981 HC SRT - p
0.0002 Spatial Advantage - p 0.0002 Total
Advantage - p 0.001
54
Additional Results Pre- vs. Post Training

• CAPD SSQ
• Listening in Quiet p 0.103
• Listening in Noise p 0.0002
• TOVA-A
• Omissions p 0.168
• Commissions p 0.0004
• TAPS-3
• Memory Index p 0.003

55
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.

56
Method Phase II Clinical Study

• 20 children - LISN-S spatial advantage gt2SD from
  mean
• 10 x LiSN Learn (experimental group)
• 10 x Earobics (control group)
• Questionnaire
• Participant (LIFE)
• Parent (Fishers)
• Teacher (LIFE)
• LiSN Learn or Earobics training 15 minutes
  per day
• Re-evaluate LiSN-S and questionnaires
  post-training
• Offer LiSN Learn to control group.

56
57
Phase II Study - LiSN Learn Group (n1)
SD from Mean
58
Phase II Study - Earobics Group (n1)
SD from Mean
59
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.

60
LiSN Screening Test

• Client data
• End-user inputs client data
• Sound check
• Sets output level of computer soundcard
• Reference tone consists of pulsed speech-shaped
  broadband noise
• Reference tone is presented at 40 dB below level
  of combined distracters
• Listener adjusts volume control until he or she
  can just hear the reference tone
• Assumed to be at least 10 dB SPL
• Therefore level of distracters presented during
  test is approx 50 dB SPL

61
LiSN Screening Test

• Word familiarization task (in quiet)
• 3 target words (red, blue, green)
• 12 foils (e.g. hat, doll, milk)
• Listener clicks on picture that matches word
  until all words correctly identified.
• LiSN Screening Test
• Distracters looped stories (DV /- 90º)
• Targets and foils
• Female 1 at 0º
• initially presented at SNR of 4 dB
• 2 second ISI
• Listener clicks mouse when target heard.
• Adaptive procedure used to find SRT that yields
  50 intelligibility.
• Level of word stimuli adjusted in 3 dB steps.
• At least 6 targets presented as practice.
• SRT calculated over up to 40 scored targets

62
LiSN-S Screening Test Studies

• Target Stimulus Equalization Study
• 30 adults aged 18 to 29 years
• SRT of scored target words (red, blue, green)
  consolidated across participants and psychometric
  functions formulated
• Amplitude of target words adjusted for equal
  intelligibility
• Sensitivity and Specificity Study
• 40 children and adults with suspected CAPD
• Tested with LiSN Screening Test at referring
  centre
• Tested with LiSN-S no more than 3 weeks later at
  NAL
• Correlation between LiSN Screening Test and
  LiSN-S determined
• ROC analysis used to determine sensitivity and
  specificity
• Optimum criteria cut-off scores determined

63
LiSN-S Prescribed Gain Amplifier
64
CAPD and Hearing Impairment Studies

• LiSN-S Study
• 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
• LiSN-S PGA
• LIFE Questionnaire (6-17 years)
• SSQ Questionnaire (18-60 years)
• COGNISTAT (60 years)
• LiSN Learn Study
• 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
• LiSN-S PGA
• Memory Test
• LIFE Questionnaire (6-17 years)
• SSQ Questionnaire (18-60 years)

65
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), 377-391.
• 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)
  Test-retest reliability study. International
  Journal of Audiology, 46, 145-153.

66
Acknowledgements and QA

• Dr Harvey Dillon
• Director of Research
• National Acoustic Laboratories
• Helen Glyde
• Research Audiologist
• National Acoustic Laboratories