1. Outcomes for wearers of hearing aids and improving hearing aid technology Harvey Dillon NAL CRC Hear Denis Byrne Oration Canberra, 2008.

2. Who benefits from hearing aids? What can hearing aids do for people with hearing loss? How can we make hearing aids work better? Dillon, NAL

3. The bits of this talk …. Who’s got hearing aids Who should have hearing aids Who’s got hearing aids but shouldn’t How people misjudge their hearing Why hearing aids are sometimes useless How technology is changing candidacy Hearing aids of the future What we should do differently now Dillon, NAL

4. Who is using hearing aids? Of those with >25 dB 4FAHL in better ear Don’t have 67 % Don’t use 10 % Use 23 % Source: Blue Mountains Study (Mitchell, Hartley et al) Australia UK Davis (2003) USA Kochkin (1992) Dillon, NAL

5. Percentage penetration of hearing aids Mitchell (2002) Dillon, NAL

6. Hearing loss in the future Sources: ABS series B Sth Aust population study Possible further increase from: Personal stereo use ↑  Rock music  ↑ Power tools  ↑ Premature baby survival  ↑ And decrease from: War exposure ↓ Manufacturing ↓ Rubella epidemics ↓ Dillon, NAL

7. Growth in people with hearing loss (>25 dB 4FAHL better ear) Blue squares = 2.5% compound growth Source: Hartley & Dillon, unpublished data Over 55 years Over 65 years Dillon, NAL

8. Growth in OHS voucher numbers Blue squares = 9% compound growth Dillon, NAL

9. Penetration: Hearing aid owners as a proportion of those with >25 dB 4FAHL better ear Hearing impaired growth: 2.5% OHS vouchers: 9% OHS vouchers: 5% Dillon, NAL

10. Conundrum 1.Older people more likely to need a hearing aid 2.Younger people more likely to adapt well to using a hearing aid Alberti (1977); Brooks (1985) Implication We need to know who will benefit from a hearing aid so those people get them as soon as possible Dillon, NAL

11. What should penetration be? Who does benefit from a hearing aid? Dillon, NAL

12. Experiment To determine the minimum hearing loss for which clients will receive benefit from hearing aids. –Previous research has not indicated a close relationship between benefit and hearing thresholds. –Some people with very mild losses are being fitted in the current scheme. –It is extremely unlikely that people with normal hearing would benefit from hearing aids. Should be possible to find the minimum aidable hearing loss Dillon, NAL

13. Procedure 400 clients sampled from OHS voucher database –41,521 new clients fitted Feb to Sept, 2004 Audiometric and other details obtained from selected clients’ files Questionnaire sent to selected clients –International Outcome Inventory for Hearing Aids –Plus 6 purpose-designed questions Selected clients followed up by phone or additional mail to get a high response rate (effectively 86%) Dillon, NAL

14. Hearing loss characteristics of study sample Dillon, NAL

15. Usage of hearing aids Dillon, NAL

16. Factor analysis of questionnaire Factor Loadings Factor 1Factor 2Factor 3 Q1: want aids0.690.300.21 Q2: difficulty unaided0.700.410.25 Q3: use0.74-0.180.08 Q4: benefit0.82-0.320.00 Q5: residual difficulty0.03-0.76-0.33 Q6: Worth it0.83-0.33-0.00 Q7: Residual handicap-0.29-0.56-0.06 Q8: Bother to others-0.18-0.68-0.26 Q9: Quality of life0.82-0.320.02 Q10: Replace them0.34-0.15-0.23 Q11: Face vision-0.29-0.420.74 Q12: paper vision-0.22-0.470.70 Proportion of variance0.32200.12 International Outcomes Inventory for Hearing Aids Dillon, NAL

17. Factor analysis of questionnaire Factor Loadings Factor 1Factor 2Factor 3 Q1: want aids0.690.300.21 Q2: difficulty unaided0.700.410.25 Q3: use0.74-0.180.08 Q4: benefit0.82-0.320.00 Q5: residual difficulty0.03-0.76-0.33 Q6: Worth it0.83-0.33-0.00 Q7: Residual handicap-0.29-0.56-0.06 Q8: Bother to others-0.18-0.68-0.26 Q9: Quality of life0.82-0.320.02 Q10: Replace them0.34-0.15-0.23 Q11: Face vision-0.29-0.420.74 Q12: paper vision-0.22-0.470.70 Proportion of variance0.32200.12 Composite benefitComposite difficultyVision International Outcomes Inventory for Hearing Aids Dillon, NAL

18. Simple correlations People who more strongly wanted to get hearing aids: Use them more (Q3) Benefit from them more (Q4) Say they are worth it (Q6) Improve their enjoyment of life by using them (Q9) Would replace their hearing aids if lost (Q10) People who had the most difficulty unaided: Use their hearing aids more (Q3) Benefit from them more (Q4) Say they are worth it (Q6) Improve their enjoyment of life by using them (Q9) Would replace their hearing aids if lost (Q10) Dillon, NAL

19. Use Benefit Satisfaction QOL + + + Composite Benefit Dillon, NAL

20. Composite benefit for different daily usage High use goes with high benefit and vice-versa Dillon, NAL

21. What might account for variation in benefit? Hearing loss Age Gender Type of hearing aid Difficulty listening unaided Original desire to get hearing aids Visual ability Dillon, NAL

22. Difficulty hearing unaided and wish to get hearing aids Unaided difficulty related to wish to get hearing aids Dillon, NAL

23. Desire to get hearing aids + Need Difficulty listening unaided Dillon, NAL

24. Composite benefit Composite difficulty Better ear 3FA0.09-0.18 Worse ear 3FA0.13-0.17 Better ear 4FA0.08-0.23 Worse ear 4FA0.13-0.20 Age-0.150.03 Need strength0.51-0.44 Vision summary-0.080.19 Relationship between predictors and outcomes Only self-assessed need predicts outcomes Dillon, NAL

25. Effect of hearing loss on benefit Dillon, NAL

26. Effect of hearing loss on benefit Dillon, NAL

27. How is composite benefit related to need? Dillon, NAL

28. Benefit versus need Dillon, NAL

29. “I don’t wear my hearing aids – never did. I don’t know why they gave them to me.” - Participant 1-089 Dillon, NAL

30. Benefit for different degrees of hearing loss Dillon, NAL

31. Benefit for different hearing aid types Dillon, NAL

32. Benefit for top-up and free-to-client Dillon, NAL

33. Are outcomes affected by the provider the client goes to? Dillon, NAL

34. Benefit for different contractors Contractor C clients get less benefit, on average P=0.0004 Dillon, NAL

35. Why? Dillon, NAL

36. Hearing loss for different contractors Contractor C clients are less deaf 8 dB Dillon, NAL

37. Need strength for different contractors Contractor C clients express less need for assistance 0.8 scale points Dillon, NAL

38. Which: hearing loss or need? Allow for differences in hearing loss  difference in benefit remains (p=0.002) Allow for the differences in need  difference in benefit disappears (p=0.33) Dillon, NAL

39. Benefit vs Needs applies to all contractors Contractors A, B, D and E Contractor C Dillon, NAL

40. Implication Benefit is much more strongly determined by need than by hearing loss. “Need” = difficulty listening unaided + desire to get hearing aids in first place Dillon, NAL

41. Why don’t people with hearing loss acquire hearing aids? “My hearing loss is not bad enough to need them” (Kochkin, 1993) –beliefs about difficulties they are having –beliefs about hearing aid likely benefits –beliefs about emotional consequences of wearing hearing aids –beliefs about practical issues (expense, complexity, manipulation) Dillon, NAL

42. People act rationally, in their best interests, based on their beliefs Health belief model Hearing loss Cost Difficulties experienced: frequency, severity Self- image Ability to manage Hearing aid effectiveness Effect on others’ view Inconven -ience Dillon, NAL

43. People act rationally, in their best interests, based on their beliefs Health belief model Hearing loss Cost Difficulties experienced: frequency, severity Self- image Ability to manage Hearing aid effectiveness Effect on others’ view Inconven -ience Dillon, NAL

44. People act rationally, in their best interests, based on their beliefs Health belief model Hearing loss Cost Difficulties experienced: frequency, severity Self- image Ability to manage Hearing aid effectiveness Effect on others’ view Inconven -ience Dillon, NAL

45. Dominant community belief I don’t want hearing aids Circle of negative beliefs Hearing aids don’t work Acquire hearing aids anyway “Prove” that hearing aids don’t work Tell everyone positive Dillon, NAL

46. Expectations and benefit Higher expectations  greater use and benefit (Jerram & Purdy, 2001) Higher expectations  higher benefit (Cox & Alexander). Expectations Outcomes Satisfaction Use, benefit Dillon, NAL

47. What can a hearing aid actually do? 1.Amplify soft sounds 2.Emphasise frontal sounds 2501255001k2k4k8k 0 20 40 60 80 100 120 Frequency (Hz) Hearing threshold (dB HL) 35 dB 4FA HL Dillon, NAL

48. 1.Amplifying soft sounds Speech at 55 dB SPL Speech intelligibility index = 0.45  Percent words in sentences correct = 93% Dillon, NAL

49. Amplifying speech (quiet; no reverberation) People with mild to moderate loss can cope reasonably well in quiet. Dillon, NAL

50. 2. Speech in noise and reverberation Noise and reverberation both usually have biggest effect on low frequencies Dillon, NAL

51. Amplifying soft sounds Speech at 55 dB SPL Speech intelligibility index = 0.45  Percent words in sentences correct = 93% Dillon, NAL

52. Amplifying soft sounds Speech at 55 dB SPL Speech intelligibility index = 0.24  Percent words in sentences correct = 72% Dillon, NAL

53. Solution A directional microphone to lift the speech in front, but not the noise but ….. Dillon, NAL

54. Room acoustics Distance SPL Critical distance Direct Reverberant Total Dillon, NAL

55. Room acoustics Distance SPL Critical distance Direct Reverberant Total Dillon, NAL

56. Implication for beliefs about hearing? Speech with no noise, no reverberation  I can understand!  My hearing is OK Louder speech, noise, reverberation  I can’t understand  The noise makes it hard to understand, (My hearing is fine) Dillon, NAL

57. Implication for beliefs about hearing aids Speech with no noise, no reverberation  Hearing aid helps, if needed Close speech, directional microphone, noise & reverberation  Hearing aid helps Distant speech, directional microphone, noise & reverberation  Hearing aid doesn’t help Dillon, NAL

58. Impact of untreated hearing loss Dillon, NAL

59. Impact of untreated hearing loss on health Proven links between hearing loss and : –low mood / emotional state, greater depression –reduced capability for self-sufficiency, restricted social relationships –reduced life expectancy Asserted links between hearing loss and: –loneliness, –anxiety, –paranoia, –exhaustion, –insecurity, –loss of group affiliation, –loss of intimacy, –anger Dillon, NAL

60. Effects of hearing loss? Hearing loss Depression Mortality Cardio-vascular disease Activity restriction We just can’t deduce causation from these surveys of health Dillon, NAL

61. Effects of hearing aids? Hearing loss MortalityDepression Isolation Anxiety Insecurity etc Dillon, NAL

62. Cross-sectional studies Hearing loss Hearing loss and hearing aids Less isolation. More able to deal with problems Better: Mood / less depression Emotional state Self-sufficiency Social relationships Life expectancy Dillon, NAL

63. Cross-sectional studies Hearing loss Hearing loss and hearing aids Better: Mood / less depression Emotional state Self-sufficiency Social relationships Life expectancy Pro-active people Fatalistic people Dillon, NAL

64. Cross-sectional studies Hearing loss Hearing loss and hearing aids Unwell people, with hearing loss Attend to major sickness Healthy people, with hearing loss Better: Mood / less depression Emotional state Self-sufficiency Social relationships Life expectancy Attend to hearing loss Dillon, NAL

65. Longitudinal studies Hearing loss Better: Social relationships Cognitive functioning Memory Learning ability Less depression Less paranoia + Mulrow et al (1990); Dye & Peak (1983) Dillon, NAL

66. Aged-care facilities Hearing loss Appearance of dementia Reduced auditory stimulation Cognitive decline Actual dementia ?? Improved services  Improved quality of life Dillon, NAL

67. Technology advances in the last decade Integrated wireless receiver Adaptive directional microphones Multi-channel noise reduction Feedback cancelling Environment sensing Wireless-linked hearing aids Impulse noise rejection Wax guards Data logging Integrated rechargeable batteries Dillon, NAL

68. So why no increase in satisfaction? Increase in laboratory-measured benefit No increase in real-world reported satisfaction Technology advance Marketing, hype, cost Expectations increase  Performance increases (a little)  Gap between performance and expectations - ?? Satisfaction? Dillon, NAL

69. Some technology advances in the next few years - from the CRC for Hearing, including NAL Trainable hearing aids Improved occlusion reduction Improved intelligibility in noise Hybrid cochlear implants and hearing aids Fully implanted devices (implants and hearing aids)? Dillon, NAL

70. Moving on from prescriptions The trainable hearing aid Justin Zakis, Gitte Keidser, Hugh Mcdermott, Liz Convery Dillon, NAL

71. Trainable aid – general structure Programmable amplifier Learning algorithms Acoustic measurement module User control(s) Dillon, NAL

72. Aid user adjusts settings... Trainable Aid Dillon, NAL

73. Aid user adjusts settings... Trainable Aid Dillon, NAL

74. ...the hearing aid takes note Trainable Aid Dillon, NAL

75. Process repeats for other sounds Trainable Aid Dillon, NAL

76. After training, preferred settings are automatically applied... Trainable Aid Dillon, NAL

77. Trainable Aid After training, preferred settings are automatically applied... Dillon, NAL

78. Trainable Aid After training, preferred settings are automatically applied... Dillon, NAL

79. Trainable Aid After training, preferred settings are automatically applied... Dillon, NAL

80. Trainable aid philosophy Prescribe what can be prescribed, automatically and in minimum clinical time Prescribe what can be prescribed, automatically and in minimum clinical time Leave the rest to the client (and the intelligence of the hearing aid) Leave the rest to the client (and the intelligence of the hearing aid) Fine tuning Dillon, NAL

81. Training gain, CT, CR. CR CT Gain Dillon, NAL

82. Active occlusion reduction Jorge Mejia, John Coelho (deceased) Dillon, NAL

83. H/A Canal Cartilage Hearing Aid Electronic Venting C B A ∑ - Dillon, NAL

84. Vent and amplification path transmission Amplified path Vent path Combined path Directional mic Adaptive noise suppression Dillon, NAL

85. Occlusion reduction: Mean and Standard Deviation Note that feedback gain was adjusted for all subjects, filter settings remain the same (22 ears) Dillon, NAL

86. Super-directional hearing in noise Jorge Mejia Dillon, NAL

87. Improving understanding in noise Wireless transmission √ √ √ Wireless transmission √ √ √ Directional microphones √ Directional microphones √ (Adaptive noise suppression) (Adaptive noise suppression) √ Dillon, NAL

88. Physical arrangement simulated 6 mm Dillon, NAL

89. Loss of SNR in hearing loss Dillon, NAL

90. Blind source separation matrix (Inverse based on initial 100 ms of signal) Jorge Mejia Dillon, NAL

91. The result ? Hearing impaired people who can understand better in noise than people with normal hearing. Dillon, NAL

92. Things in your ears Now: –mobile phones, –MP3 players, –portable DVD players, –personal digital assistants, –and of course ….. hearing aids. In the future: –personal navigation aids, –Voice input/output internet connection, –local area (human communication) wireless networks, –……… all voice controlled, of course Dillon, NAL

93. What do we mean by hearing loss? 2 to 3% of children are estimated to have some form of central auditory processing disorder. CAPD reduces speech intelligibility in noise, just like sensorineural hearing loss. CAPD includes a group of different deficits, which can be present singly or mutiply. CAPD can be compensated for, and can probably be remediated as well. Dillon, NAL

94. Messages so far Hearing loss is on the increase due (at least) to aging Motivation is the major determinant of benefit Hearing aid penetration is: –low, but … –highest in world, and –rapidly increasing. Fitting hearing aids to people who don’t want them spreads negative, self-fulfilling stories Technology advances have been: –worthwhile, but … –oversold, and –will continue, or even accelerate Dillon, NAL

95. Aim To increase penetration rate of hearing aids and Increase usage and benefit Dillon, NAL

96. The solution is in the hands of: Clinicians Provider owners Government Manufacturers Researchers Dillon, NAL

97. Clinicians Don’t fit people who don’t seem to want them Dillon, NAL

98. Provider owners Provide incentives to clinicians for superior outcomes, not just superior sales Dillon, NAL

99. Government Pay for outcomes, not for processes Current system specifies process Payment is made for process Quality control inspects the process Result: No control over outcomes No financial motivation for providers to improve outcomes Financial benefit if clients don’t wear hearing aids Financial motivation for providers to maximise number of fittings Dillon, NAL

100. Government (cont) Alternative scheme Pay same for assessment Pay less for fitting Pay for outcomes Result: Providers with worse than current average outcomes earn less Providers with better than current average outcomes earn more Most providers will have better than current average outcmes Huge saving by government on people who won’t be fitted Dillon, NAL

101. Government (cont) Outcomes measurement Just measure: –Use –Benefit –Satisfaction –Quality of life improvement Need to allow for: –New versus return clients –Response rate –Degree of hearing loss International Outcomes Inventory for Hearing Aids Dillon, NAL

102. Manufacturers Continue technology improvements Change marketing: – don’t oversell; – don’t confuse Pursue convergence – hearing aid – communication device – hearing protector – better than normal hearing hearing aids normalised and desired Dillon, NAL

103. Hearing device of the future Pathway to many systems: Communication Information Entertainment Speech enhancer in noise Active hearing protector (Hearing aid) Dillon, NAL

104. Noise suppression Adaptive directionality Feedback cancelling Bernafon Oticon Phonak Siemens Starkey Dillon, NAL

105. Researchers What makes a hearing aid candidate ? –What other than motivation ? –How do you measure motivation ? –How do you change motivation ? How beneficial are hearing aid features ? –For different people –For different situations Dillon, NAL

106. Future behavioural research Why don’t some people seek help? Why do some people seeking help not get hearing aids? Why do some who get hearing aids not get benefit? Dillon, NAL

107. 60.7% 38.7% 27.7% 22.9% 24.8% Results from Telscreen Testing (n=4058) Golding, 2008 N=36 N=124 N=230 N=485 N=1001 N=1270 N=850 (N= 3996) (age range 16-100 years only) >25 dB 4FAHL Worse ear (Wilson et al) Dillon, NAL

108. The life quality of people with hearing loss - in the hands of: Clinicians Provider owners Government Manufacturers Researchers Dillon, NAL

109. Thanks for your attention Slides will be on the NAL web site www.nal.gov.au From May 28 Dillon, NAL