Speech Discrimination and Spatial Hearing in Toddlers with Cochlear Implants

1. WAISMAN CENTER Binaural Hearing and Speech Laboratory Speech Discrimination and Spatial Hearing in Toddlers with Cochlear Implants Christi Hess, Ph.D CCC-SLP CI Day with the Experts May 31, 2014

3. Where we are • Access to sound • Age of implantation • Bilateral cochlear • implants (BiCIs)

4. Where we want to be Understanding the impact of early BiCIs on: ? • Fine-tuned auditory abilities • Spatial hearing ? ? • Language development

5. This is what we can do now Reaching for Sound Litovsky, Ehlers, Hess & Harris, 2013

6. Stimuli

7. Participants • 13 toddlers who use BiCIs: • Mean age: 32.4 mo. (8 Male, 5 Female) • At least 1 year of experience with CI1 at visit • Native English speaker • Primary communication mode = oral/aural • No diagnosed developmental disabilities • Did not control for: age of implant, device manufacturer, bilateral exp. • 13 toddlers with NH: • Mean age: 31.8 mo. (8 Male, 5 Female) • No history of hearing loss, ear infections, or other developmental delays • Tympsand hearing screening performed

8. Procedure Live-Voice Familiarization Training (4/5 Criterion) Pea/Key vs. Bye Testing: (4 contrasts; 18 trials each) Place Voicing(hard) Place+Voicing Voicing(easy) Place+VoicingPlace Voicing(easy) Voicing(hard)

9. NH are more accurate than BiCI * p=0.03

10. p=0.04 *

13. * * p=0.002 p=0.001 * * p=0.002 p=0.002

16. * r2=0.32 r2=0.08 r2=0.005 r2=0.07

19. Quiet = IDEAL!

20. But, unrealistic

22. Location Cues

23. - = Spatial Hearing

24. CRISP Garadat & Litovsky, 2007

25. Testing Conditions Quiet = Target (Male) = Masker (2 Females) Separated Collocated

26. CRISP Garadat & Litovsky, 2007

27. Stimuli • Target:male-talker, adaptive (starting 60 dB SPL) • Masker:2 female talkers, fixed (55 dB SPL) Garadat & Litovsky, 2007

28. Procedure Familiarization with target words • Training (4 trials) • Quiet and Collocated conditions Testing: 4-AFC task (repeated 2 times for each condition) Quiet Collocated Separated Collocated Separated Quiet Collocated Quiet Separated Quiet Separated Collocated Speech Reception Threshold (SRT) 80% correct criterion, calculated using a 3-down/1-up procedure Garadat & Litovsky, 2007

30. Better SRTs when masker is in a different location than the target

31. p=0.001 p=0.02 * * • * • * • * • * • * p<0.001 p<0.001 p<0.001

32. - = + SRM Collocated SRT Separated SRT - = 0 SRM - = Spatial Release from Masking (SRM)

34. More bilateral listening experience = greater benefit from spatial separation

35. BiCI BiCI NH NH Adult (5-7) (7-9) (5-7) (7-9) BiCI BiCI BiCI NH NH NH Adult (2-3) (5-7) (7-9) (2-3) (5-7) (7-9) Misurelli& Litovsky, 2012

36. Where we want to be Where we are Understanding the impact of early BiCIs on: • Fine-tuned auditory abilities • Spatial hearing ? • Language development

37. What does this mean? Speech Language Pathologists Auditory Verbal Therapists Parents Educators Audiologists

38. Thank you! • Members of the BHSL who have helped with data collection and analysis • Families who travel to participate • My family and friends for all of their support

39. References • Garadat, S., & Litovsky, R.Y. (2007). Speech Intelligibility in Free Field: Spatial Unmasking in Preschool Children. J. Acoust. Soc. Amer. 121: 1047-1055. • Grieco-Calub, T., Litovsky, R.Y., & Werner, L.A. (2008). Using the observer-based psychophysical procedure to assess localization acuity in toddlers who use bilateral cochlear implants. Invited paper in special issue of Otology and Neurology. 29(2):235-239. • Litovsky, R.Y., Ehlers, E., Hess, C., & Harris, S. (2013). Reaching for sound measures: An ecologically valid estimate of spatial hearing in 2- to 3-year-old children with bilateral cochlear implants. Otol. & Neurotol. 34(3): 429-435. • Misurelli, S.M., & Litovsky, R.Y. (2012). Spatial release from masking in children with normal hearing and with bilateral cochlear implants: Effect of interferer asymmetry. J. Acoust. Soc. Am. 132(1): 380-391.