New Perspectives in Central Auditory Processing Disorder

1. New Perspectives in Central Auditory Processing Disorder Sharon Cameron Harvey Dillon National Acoustic Laboratories

2. New perspectives on CAPD Description of the LiSN-S Research behind LiSN-S LiSN-S and the traditional APD test battery How to interpret LiSN-S results Management options Description of LiSN & Learn Auditory Training Software LiSN & Learn Phase I and Phase II Clinicial Trial Results LiSN Screening Test – Sensitivity and Specificity Study LiSN-S “Prescribed Gain Amplifier” - HI Study 6-60+ Years Question time Overview of Presentation

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 18:548–558

5. Source Discrimination aka Auditory Stream Segregation • 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 • 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

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. Low Cue SRT - SV0º DV0° Total Advantage Talker Advantage Spatial Advantage ° LISN-S Conditions High Cue SRT – DV90º SV 90°

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 < 0.000001

22. High Cue SRT Better High Cue SRT vs. Age Group p < 0.000001

23. Talker Advantage Talker Advantage vs. Age Group p < 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 <0.00001; r ranged from 0.3 to 0.6)

34. Spatial Advantage

35. NA LiSN-S Critical Difference Scores

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. Managing Spatial Hearing Deficits • Teacher-directed strategies • Child-directed strategies • Language training • Classroom modification (+10 dB SNR) • Assistive listening device • Training in source discrimination

46. Auditory Training Research • Developdeficit-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.

47. 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

48. 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˚)

49. Target: The horse kicked six wet shoes

50. 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