Cochlear implants and radio aids. University of Southampton Auditory Implant Service (USAIS)

Transcription

1 Cochlear implants and radio aids University of Southampton Auditory Implant Service (USAIS) Stuart Whyte, Sarie Cross, Sam Bealing 11 March 2017

2 Effective fitting of radio aids with CI Our workshop aims include: a review of the variety of systems and how they connect how to fit matching and checking based on the protocols used at USAIS methods to evaluate the benefit resource implications and when to fit an opportunity for discussing and sharing good practice 2

3 Cochlear Implant Systems at USAIS Cochlear implants can work well with radio aids. We will describe 0ur practice and experience of systems at USAIS demonstrate the CI and RA test procedure. 3

4 A leading question... What is the purpose of balancing radio aids? To ensure that the level and quality of sound a user hears through the radio aid microphone matches what they hear through the microphone of the hearing instrument or the sound processor. 4

5 UK Quality Standards: July 2008, updated February

6 QS1 Every deaf child Has potential Through technological advances and enhanced processing strategies the majority of children with hearing impairment have the potential to access all of the sounds of spoken language. Needs a sound start A good a listening experience right from the start, appropriate support and appropriate use of technology achieves better outcomes. See McCracken et al.(2012), Ching (2015) and Yoshinaga-Itano & Wiggin (2016). 6

7 QS3 Ensure the desired advantage Level too High Serious risk of distortion A distraction Danger of compression 7

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9 QS3 Ensure the desired advantage Level too High Serious risk of distortion A distraction Danger of compression Level too Low Makes little difference to the user A waste of resources and leads to disenchantment Disadvantaged access to spoken information 9

10 Getting the level right is crucial Why? Because the dynamic range of hearing for cochlear implant users is markedly reduced compared to individuals with hearing within normal limits. 10

11 What is different with CI? We can t listen to the whole system output via the processor - only a CI user can do this. However, we can monitor the input. We can: use the relevant listening accessory to monitor the radio aid signal received by the sound processor use the relevant hearing instrument test box lead to obtain the frequency response of the microphone of the sound processor and with the radio aid input. 11

12 Acoustic transparency QS8 Most devices can be balanced in the test box using specific leads 12

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14 Acoustic transparency QS8 Most devices can be balanced in the test box using specific leads Some devices require extra equipment or have to be done through the manufacturer s fitting software. Work by SOECIC (USAIS), Cochlear and the UKFMWG led to an electroacoustic test protocol for cochlear implant sound processors and radio aids that provides the desired advantage (see previous QS and guidance). also see Schafer et al. (2013) 14

15 Obtaining the curves.

16 Ready? 16

17 Processor on its own 17

18 Processor on its own 18

19 Processor and radio aid at default setting 19

20 Processor and radio aid at default setting 20

21 Processor and radio aid: new gain setting 21

22 Evaluation

23 System evaluation QS7, 8, 10 Measures of benefit must not only include objective measures, but also patient perception of benefit Clark et al. (2016:4) Observation of behaviours and functional listening Real world questionnaires (Haigh 2016, Zanin & Rance 2016) Evaluate speech recognition in quiet Evaluate speech recognition in noise with and without the radio aid system 23

24 Speech perception in noise ~ db(a) at 15-20cm speech 65dB(A) + variable noise McCormick Automated Toy Discrimination test Ousey et al. (1989), Palmer et al. (1991) Summerfield et al. (1994) and Lovett et al. (2013) 24

25 Resource Implications Timing When to fit? Radio Aid CHIP 25

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27 Resource Implications Timing When to fit? Radio Aid CHIP Processor settings and map stability Setting up and evaluation Is the child ready to do a Toy Test? 27

28 Resource Implications Provision of suitable Radio Aid QS11 what is being fitted? are there any other radio aid users in the setting? is there a particular frequency/channel needed? is there a soundfield system being used? QS12 28

29 What you can do locally Comprehensive radio aid checks on a regular basis Checking of gain settings via test box Ling sounds Speech tests Regular dialogue with user for their feedback liaison with implant centre 29

30 In summary: plan, liaise, fit, match & check UKFMWG Quality Standards for the use of personal radio aids: Promoting easier listening for deaf children (NDCS 2017) Consider candidacy, ability and experience QS1, 2 Liaise well QS9, 11 Ensure that the sound level is appropriate for the child QS3 Monitor and evaluate regularly QS4, 7, 8, 10, 12 Keep up to date QS5, 6 30

31 Any questions? Discussion points?

32 References Clark J.L., Pustejovsky C. & Vanneste S Objective and perceptual comparisons of two bluetooth hearing aid assistive devices. Disability and Rehabilitation: Assistive Technology, 1-4. Dillon H., James A. & Ginis J Client Oriented Scale of Improvement (COSI) and its relationship to several other measures of benefit and satisfaction provided by hearing aids. Journal of the American Academy of Audiology, 8, Haigh C LIFE-R questionnaire. BATOD Magazine. January: Text also available at: 32

33 References Lovett R., Summerfield Q. & Vickers D Test-retest reliability of the Toy Discrimination Test with a masker of noise or babble in children with hearing impairment. International Journal of Audiology, 52, McCracken W., Roberts A., Wilding T. (2012). Oticon Foundation Study of FM in Real World Settings. Manchester University. Report downloadable from: Ousey J., Sheppard S., Twomey T. & Palmer A.R The IHR-McCormick Automated Toy Discrimination test--description and initial evaluation. British Journal of Audiology, 23, Palmer A.R., Sheppard S. & Marshall D.H Prediction of hearing thresholds in children using an automated toy discrimination test. British Journal of Audiology, 25,

34 References Schafer E.C., Musgrave E., Momin S., Sandrock C. & Romine D A proposed electroacoustic test protocol for personal FM receivers coupled to cochlear implant sound processors. Journal of the American Academy of Audiology, 24, Summerfield Q., Palmer A.R., Foster J.R., Marshall D.H. & Twomey T Clinical evaluation and test-retest reliability of the IHR-McCormick Automated Toy Discrimination Test. British Journal of Audiology, 28, Yoshinaga-Itano C. & Wiggin M A Look into the Crystal Ball for Children Who Are Deaf or Hard of Hearing: Needs, Opportunities, and Challenges. Seminars in Speech and Language, 37, Zanin J. & Rance G Functional hearing in the classroom: assistive listening devices for students with hearing impairment in a mainstream school setting. International Journal of Audiology, 55,

35 Thank you for coming. University of Southampton Auditory Implant Service (USAIS) Stuart Whyte, Sarie Cross, Sam Bealing BATOD Conference 2017