Breaking the Sounds of Silence - PowerPoint Presentation

1. Breaking the Sounds of SilenceAdult Cochlear Implant Forum 11 March 2017 Cochlear Implant Research in New Zealand (45 minutes): 1.45-2.30 pm, 2.45-3.30 pm, 3.45-4.30 pmSuzanne C PurdySpeech ScienceSchool of Psychology

2. CaptioningWorkshop: NZ Research (SP) Suzanne Purdy Room 731.203 (LC)http://captioningstudio.com/live/?bookingref=GXMG5DZP48203&fs=40bookingref=GXMG5DZP48203Live stream: https://auckland.zoom.us/j/828466835 

3. Improvements in speech perception over time are well documented for cochlear implant usersMost improvement occurs within a short time after cochlear implantation in adultsSome studies show a plateau in performance after several yearsAuditory evoked potentials (brain responses to sound) are of interest as they provide an objective measure of auditory brain changeSome evoked potential measures, especially cortical evoked potentials, correlate with performanceBackground3

4. TopicsAuditory evoked potentialsAuditory plasticity and trainingCognition and speech in noise in people with cochlear implantsProcessing of speech emotion (‘prosody’)(5 published New Zealand studies)

5. Recording brain responses to sound: cortical auditory evoked responses5http://www.the-scientist.com/?articles.view/articleNo/43843/title/The-Sounds-of-Silence/

6. Recording auditory evoked potentialshttp://images.slideplayer.com/11/3189898/slides/slide_3.jpg

7. 1. Electrophysiological and speech perception measures of auditory processing in experienced adult cochlear implant usersAS Kelly, SC Purdy, PR Thorne (2005). Clin Neurophys 116:1235-46. 250 Hz4 kHzBlack = control groupRed = ‘better’ CI: sentence scores >85%Blue = ‘poorer’ CI: sentence scores <40%Age range 27–74 years CI use 1.3-5.2 yearsNucleus CI–22MEvoked potentials recorded to tones delivered via loudspeaker P1N1P2P1N1P2

8. 2. Speech scores improve over timeSeminars in Hearing Volume 37 (1) · February 2016CI24 implant users

9. Evoked potentials improve over time, but with differing time course: 57 year old with congenital hearing loss, profoundly deaf for 10 years. P1 changed very little, N1 reached stable amplitudes at 1 month, P2 increased in amplitude over the 9 months.Switch on1 month3 months6 months9 monthsP1N1P2

10. Improvements in P2 area over the five visitsno change for most electrode locations over first 6 months8 of the 10 people had right ear implantssteady P2 increase over time for C4 (right hemisphere recording)https://www.sunshinecoastdaily.com.au/news/dad-gets-cochlear-implant-tattoos-support-his-kids/2991160/

11. 11http://aja.pubs.asha.org/article.aspx?articleid=2573094 3.

12. Auditory training is a way to reduce variability in CI outcomesSound and Beyond (Cochlear)Hearing for Life (Advanced Bionics)only a few independent studies have trialed these programs independently from the developers (Fu et al., 2007 & Stacey et al., 2010)

13. Speech in noise scores [and spectral (pitch) discrimination] improved after training13

14. 14N1-P2 amplitude significantly larger post-training for /baba/ stimulus in quietPre trainingPost trainingP1N1P2P1N1P2

15. 4. Impact of cognition and noise reduction on speech perception in adults with unilateral cochlear implants Investigators: Suzanne Purdy¹, David Welch2, Ellen Giles², Catherine Morgan3, Renique Tenhagen¹, Abin Kuruvilla-Mathew¹¹Speech Science, Faculty of Science, University of Auckland²Audiology, Faculty of Medical & Health Sciences, University of Auckland3Cochlear Ltd, Sydney, Australiain press, Cochlear Implants International

16. What is cognition?cog·ni·tion /kägˈniSHən/NounThe mental action or process of acquiring knowledge and understanding through thought, experience, and the senses. A result of this; a perception, sensation, or intuition.Synonymsknowledge – cognizance – acquaintancehttp://www.mcgill.ca/cogsci/

17. Cognitive processesExecutive function (“involved in complex cognitions, such as solving novel problems, modifying behaviour in the light of new information, generating strategies or sequencing complex actions” Elliot 2003 p.50)MemoryAttention Reference: R. Elliot. Executive functions & their disorders. British Medical Bulletin 2003;65:49–59)

18. Listening to speech in noise [effortful listening] depends on hearing and cognitionhttp://www.brainvolts.northwestern.edu/projects/speech/speechinnoise/index.php

19. http://thebrain.mcgill.ca/flash/a/a_07/a_07_p/a_07_p_tra/a_07_p_tra.html

20. Links between cognition and speech perception with hearing aidsThomas Lunner (2003) Cognitive function in relation to hearing aid use. International Journal of Audiology, 42:sup1, 49-58.Thomas Lunner, Mary Rudner, Jerker Rönnberg (2009). Cognition and hearing aids. Scandinavian Journal of Psychology, 50, 395–403Reading span task – process & retain information simultaneouslyWorking memory capacity measured by the reading span test influenced speech recognition thresholds in 72 new hearing aid users (40% of variance)

21. Reading span correlated with speech perception in noise in new hearing aid usersParticipants listen to sequences of letters that need to be recalled at the end Each letter in the sequence is preceded by an auditory semantic categorization test – sentence makes sense? yes or no?Letter recall is tested by asking participants to select letters they have already seen from a provided letter matrixhttp://www.millisecond.com/download/library/v5/ListeningSpan/AutomatedLSPAN.manual

22. Processing sentencesThe host greeted all the guests and asked them to sit at the {table | sky}.John never liked {crowds | chocolate} and that is why he now lives in the country.http://www.pitt.edu/~tol7/res/research/psych-tests/rspan/

23. Questions 1. Does SmartSound iQ (SNR-NR) noise reduction algorithm improve speech perception and decrease listening effort for CI recipients listening to speech in noise?2. What is the ability of people with poorer or better cognitive ability to benefit from the noise reduction?

24. Significant improvement in fixed SNR word score with SNR-NR on, independent of cognitive ability & age (N=13)7% average Improvement

25. Dual taskPrimary listening task (repeat sentences in noise)Secondary visual task correct identification of a number in a visual stream of numbersspeed & accuracy measuredSignal+Noise

26. Cognitive ability measured using Weschler Adult Intelligence Scale Fourth Edition (WAIS-IV Wechsler, 2008) Auditory digit span: forwards, backwards, sequencing (working memory), for exampleForward: 7 5 6 2 5 3 = 7 5 6 2 5 3Backward: 7 5 6 2 5 3 = 3 5 2 6 5 7Sequence: 7 5 6 2 5 3 = 2 3 5 5 6 7Coding: total number of correct symbols in timed period (processing speed)

27. Good vs. poor working memoryTrend for scores to be better with noise reduction ON for those with better with working memory during dual taskNo difference in speech scores with noise reduction ON vs. OFF for those with poorer working memory

28. Recognising emotion in speech (happy, sad, fearful, angry)5. International Journal of Audiology 54(7), 444-452, 2015

29. Key pointsSpeech perception with a CI varies but improves with experience and with trainingBrain responses to sound reflect auditory deprivation and can change over time with a CI (brain ‘plasticity’)Some brain responses correlate with performance but this differs across studiesImproved auditory attention and/or pitch perception could mediate improved P2 evoked responsesWorking memory may influence speech perception scores and interact with CI processing (further research underway)Perception of emotion in speech may be challenging – this could add to listening effort

30. Cognitive load Questions?http://www.fitwise.co.uk/files/9314/6356/5133/Pramudi_Wijayasiri.pdf

31. AcknowledgementsCI participantsDeafness Research FoundationCochlear LtdPindrop FoundationQuestions? Email me at sc.purdy@auckland.ac.nz

32. AbstractNew Zealand hearing researchers have been investigating outcomes and rehabilitation for adults using cochlear implants since the 1990s. This presentation will talk about findings of some of this research, including variable speech perception outcomes for adults and factors contributing to this. Changes in the auditory brain have been shown using auditory evoked potentials (electrical activity from the brain in response to sound that can be measured with sensors on the scalp). Brain changes occur within a short time after an adult receives a cochlear implant and continue over an extended period. Recent research has shown that adults who have used their implants for a long time can still benefit from auditory training and noise reduction in the cochlear implant improves speech outcomes but this may depend on cognitive factors such as memory.