Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Evolution of mammalian auditory ossicles wikipedia , lookup
Telecommunications relay service wikipedia , lookup
Hearing loss wikipedia , lookup
Hearing aid wikipedia , lookup
Sensorineural hearing loss wikipedia , lookup
Noise-induced hearing loss wikipedia , lookup
Audiology and hearing health professionals in developed and developing countries wikipedia , lookup
Outcomes for wearers of hearing aids and improving hearing aid technology Harvey Dillon NAL CRC Hear Denis Byrne Oration Canberra, 2008. 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 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 Who is using hearing aids? Of those with >25 dB 4FAHL in better ear Use Australia UK USA 23 % Don’t have 67 % Don’t use 10 % Davis (2003) Source: Blue Mountains Study (Mitchell, Hartley et al) Kochkin (1992) Dillon, NAL Percentage of people with hearing aids Percentage penetration of hearing aids 120% 107% 100% 92% 80% 57% 55% 60% Mitchell (2002) 40% 20% 11% 17% 1% 0% 0-24 25-44 45-64 65-120 Hearing threshold (4FA dB HL) Dillon, NAL Hearing loss in the future Sources: Proportion of population with >=25 dB 4FAHL ABS series B Sth Aust population study Percentage of population 25.0% 20.0% 70 & over 15.0% 60-69 10.0% 50-59 5.0% 15-49 0.0% 2003 Possible further increase from: 2006 2011 2021 2031 Year And decrease from: Personal stereo use ↑ War exposure ↓ Rock music ↑ Manufacturing ↓ Power tools ↑ Rubella epidemics ↓ Premature baby survival ↑ Dillon, NAL Growth in people with hearing loss People with hearing loss (million) (>25 dB 4FAHL better ear) 5 Blue squares = 2.5% compound growth 4 3 2 1 0 2000 2005 2010 2015 2020 Source: Hartley & Dillon, unpublished data 2025 2030 Dillon, NAL Growth in OHS voucher numbers OHS vouchers issued 250,000 200,000 150,000 100,000 Blue squares = 9% compound growth 50,000 0 2000 2002 2004 Year 2006 2008 Dillon, NAL Penetration: Penetratration rate Hearing aid owners as a proportion of those with >25 dB 4FAHL better ear 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% 2000 Hearing impaired growth: 2.5% 2010 2020 2030 Year Dillon, NAL 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 What should penetration be? Who does benefit from a hearing aid? Dillon, NAL 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 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 Percentage of population Hearing loss characteristics of study sample 100 80 60 Better ear Worse ear Left fitted Right fitted 40 20 0 0 20 40 60 80 100 120 3 FA Hearing Loss (dB) Dillon, NAL Usage of hearing aids 120 35% 100 80 21% 19% 60 13% Number of clients 40 10% 20 0 None 1-4 hrs/day >8 hrs/day <1 hr/day 4-8 hrs/day Q3: Daily usage Dillon, NAL Factor analysis of questionnaire Factor Loadings International Outcomes Inventory for Hearing Aids Factor 1 Factor 2 Factor 3 Q1: want aids 0.69 0.30 0.21 Q2: difficulty unaided 0.70 0.41 0.25 Q3: use 0.74 -0.18 0.08 Q4: benefit 0.82 -0.32 0.00 Q5: residual difficulty 0.03 -0.76 -0.33 Q6: Worth it 0.83 -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 life 0.82 -0.32 0.02 Q10: Replace them 0.34 -0.15 -0.23 Q11: Face vision -0.29 -0.42 0.74 Q12: paper vision -0.22 -0.47 0.70 Proportion of variance 0.32 20 0.12 Dillon, NAL Factor analysis of questionnaire Factor Loadings International Outcomes Inventory for Hearing Aids Composite benefit Factor 1 Factor 2 Factor 3 Q1: want aids 0.69 0.30 0.21 Q2: difficulty unaided 0.70 0.41 0.25 Q3: use 0.74 -0.18 0.08 Q4: benefit 0.82 -0.32 0.00 Q5: residual difficulty 0.03 -0.76 -0.33 Q6: Worth it 0.83 -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 life 0.82 -0.32 0.02 Q10: Replace them 0.34 -0.15 -0.23 Q11: Face vision -0.29 -0.42 0.74 Q12: paper vision -0.22 -0.47 0.70 Proportion of variance 0.32 20 0.12 Composite difficulty Vision Dillon, NAL 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 Use + Benefit + Satisfaction Composite Benefit + QOL Dillon, NAL Composite benefit for different daily usage 40 11% 10% 35 9% 30 25 7% 7% 20 15 4% 4% 10 2% Number of people 5 1% 0 0.5 1.5 1.0 0% 0% 0% 0% 0% 0% 2.5 2.0 3.5 3.0 4.5 4.0 5.5 0% 3% 2% 2% 1% 0.5 5.0 3% 0% 0% 0% 0% 1.5 1.0 2.5 2.0 No use 3.5 3.0 4.5 4.0 5.5 5.0 0% 0% 0% 0.5 1.5 1.0 <1 hour per day 0% 0% 2.5 2.0 3.5 3.0 4.5 4.0 5.5 5.0 1 to 4 hours per day 40 35 30 25 6% 20 15 5% 4% 4% 10 5 0 0% 0% 1% 0% 1.5 0.5 1.0 2% 2% 2% 1% 0% 2.5 2.0 3.5 3.0 High use goes with high benefit and vice-versa 6% 4.5 4.0 4 to 8 hours per day 5.5 5.0 0% 0% 0% 1% 0% 1.5 0.5 1.0 2.5 2.0 0% 3.5 3.0 4.5 4.0 >8 hours per day 5.5 5.0 Dillon, NAL 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 Difficulty hearing unaided and wish to get hearing aids 60 50 40 30 20 10 0 1 2 3 4 5 Q2: No dif f iculty unaided 1 2 3 4 5 Q2: Slight dif f iculty unaided 1 2 3 4 5 Q2: Moderate dif f iculty unaided 60 No of obs 50 40 30 20 10 0 1 2 3 4 5 Q2: Quite a lot of dif f iculty unaided 1 2 3 4 5 Unaided difficulty related to wish to get hearing aids Q2: Very much dif iculty unaided Q1: Want hearing aids Dillon, NAL Difficulty listening unaided + Need Desire to get hearing aids Dillon, NAL Relationship between predictors and outcomes Composite benefit Composite difficulty Better ear 3FA 0.09 -0.18 Worse ear 3FA 0.13 -0.17 Better ear 4FA 0.08 -0.23 Worse ear 4FA 0.13 -0.20 Age -0.15 0.03 Need strength 0.51 -0.44 Vision summary -0.08 0.19 Only self-assessed need predicts outcomes Dillon, NAL Effect of hearing loss on benefit 5.0 4.5 4.0 3.5 3.0 2.5 Composite benefit 2.0 1.5 1.0 10-19 20-29 30-39 4FA HL in better ear (dB HL) 40-49 Dillon, NAL Effect of hearing loss on benefit 5.0 4.5 Composite benefit 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0-9.9 20-29.9 10-19.9 40-49.9 30-39.9 60-69.9 50-59.9 Poorer ear 3FA range (dB HL) Dillon, NAL How is composite benefit related to need? Dillon, NAL Benefit versus need 5.0 4.5 Composite benefit 4.0 3.5 3.0 2.5 2.0 1.5 1.0 1 1.5 2 2.5 3 3.5 Strength of need 4 4.5 5 Dillon, NAL “I don’t wear my hearing aids – never did. I don’t know why they gave them to me.” - Participant 1-089 Dillon, NAL Benefit for different degrees of hearing loss Current effect: F(14, 173)=.72691, p=.74537 5.0 4.5 Composite benefit 4.0 3.5 3.0 2.5 2.0 Worse ear 4FA: 20-29 Worse ear 4FA: 30-39 Worse ear 4FA: 40-49 1.5 1.0 1 1.5 2 2.5 3 Need strength 3.5 4 4.5 Dillon, NAL Benefit for different hearing aid types Current effect: F(12, 259)=1.3462, p=.19262 5.0 4.5 Composite benefit 4.0 3.5 3.0 2.5 2.0 1.5 ITE BTE ITC 1.0 1.5 2 2.5 3 Need strength 3.5 4 4.5 Dillon, NAL Benefit for top-up and free-to-client Top-up effect: F(8, 298)=1.2330, p=.27927 5.0 4.5 Composite benefit 4.0 3.5 3.0 2.5 2.0 1.5 Free-to-client Top-up 1.0 1 1.5 2 2.5 3 Need strength 3.5 4 4.5 5 Dillon, NAL Are outcomes affected by the provider the client goes to? Dillon, NAL Benefit for different contractors 4.2 4.0 P=0.0004 3.8 Composite benefit 3.6 3.4 3.2 3.0 2.8 2.6 2.4 2.2 2.0 1.8 A B C D E Contractor group Contractor C clients get less benefit, on average Dillon, NAL Why? Dillon, NAL Hearing loss for different contractors 54 52 Worse ear 4FA (dB HL) 50 48 46 44 42 40 8 dB 38 36 34 32 30 A B C D E Contractor group Contractor C clients are less deaf Dillon, NAL Need strength for different contractors 3.8 3.6 3.4 Need strength 3.2 3.0 2.8 0.8 scale points 2.6 2.4 2.2 2.0 1.8 A B C D E Contractor group Contractor C clients express less need for assistance Dillon, NAL 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 Benefit vs Needs applies to all contractors Contractor C excluded Current effect: F(8, 231)=7.0382, p=.00000 5.0 4.5 Contractors A, B, D and E 4.0 3.5 3.0 Contractor C alone Current effect: F(7, 68)=8.7632, p=.00000 2.5 it" + "Q9: QOL")/4 5.0 2.0 Contractor C 4.5 1.5 4.0 1 1.5 2 2.5 3 3.5 4 3.5 4.5 5 Need strength 3.0 2.5 it" + "Q9: QOL")/4 Composite Composite benefit: =("Q3: use" + "Q4: benefit" + "Q6: 1.0 2.0 1.5 1.0 1 1.5 2 2.5 3 Need strength 3.5 4 4.5 Dillon, NAL 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 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 Health belief model People act rationally, in their best interests, based on their beliefs Selfimage Cost Effect on others’ view Inconven -ience Hearing aid effectiveness Ability to manage Difficulties experienced: frequency, severity Hearing loss Dillon, NAL Health belief model People act rationally, in their best interests, based on their beliefs Dillon, NAL Health belief model People act rationally, in their best interests, based on their beliefs Dillon, NAL Circle of negative beliefs positive I don’t want hearing aids Dominant community belief Hearing aids don’t work Tell everyone Acquire hearing aids anyway “Prove” that hearing aids don’t work Dillon, NAL Expectations and benefit • Higher expectations greater use and benefit (Jerram & Purdy, 2001) • Higher expectations higher benefit (Cox & Alexander). Outcomes Use, benefit Satisfaction Expectations Dillon, NAL What can a hearing aid actually do? 1. Amplify soft sounds 2. Emphasise frontal sounds Frequency (Hz) 125 250 500 1k 2k 4k 8k Hearing threshold (dB HL) 0 20 40 60 80 35 dB 4FA HL 100 120 Dillon, NAL Speech level and threshold (dB SPL) 1. Amplifying soft sounds 90.0 80.0 70.0 Speech at 55 dB SPL 60.0 50.0 40.0 30.0 20.0 10.0 100 1000 10000 Frequency (Hz) Speech intelligibility index = 0.45 Percent words in sentences correct = 93% Dillon, NAL Intelligibility (% correct) Amplifying speech (quiet; no reverberation) 100 80 60 Unaided Aided 40 20 0 40 50 60 70 80 Speech level (dB SPL) People with mild to moderate loss can cope reasonably well in quiet. Dillon, NAL 2. Speech in noise and reverberation Noise and reverberation both usually have biggest effect on low frequencies Dillon, NAL Speech level and threshold (dB SPL) Amplifying soft sounds 90.0 80.0 70.0 60.0 Speech at 55 dB SPL 50.0 40.0 30.0 20.0 10.0 100 1000 10000 Frequency (Hz) Speech intelligibility index = 0.45 Percent words in sentences correct = 93% Dillon, NAL Speech level and threshold (dB SPL) Amplifying soft sounds 90.0 80.0 70.0 60.0 Speech at 55 dB SPL 50.0 40.0 30.0 20.0 10.0 100 1000 10000 Frequency (Hz) Speech intelligibility index = 0.24 Percent words in sentences correct = 72% Dillon, NAL Solution A directional microphone to lift the speech in front, but not the noise but ….. Dillon, NAL Room acoustics SPL Total Reverberant Direct Critical distance Distance Dillon, NAL Room acoustics SPL Total Reverberant Direct Critical distance Distance Dillon, NAL 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 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 Impact of untreated hearing loss Dillon, NAL 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 Effects of hearing loss? Hearing loss Mortality Cardio-vascular disease Depression Activity restriction We just can’t deduce causation from these surveys of health Dillon, NAL Effects of hearing aids? Mortality Depression Hearing loss Isolation Anxiety Insecurity etc Dillon, NAL Cross-sectional studies Hearing loss Better: Less isolation. More able to deal with problems Mood / less depression Emotional state Self-sufficiency Social relationships Hearing loss and hearing aids Life expectancy Dillon, NAL Cross-sectional studies Fatalistic people Hearing loss Better: Mood / less depression Pro-active people Emotional state Self-sufficiency Social relationships Hearing loss and hearing aids Life expectancy Dillon, NAL Cross-sectional studies Unwell people, with hearing loss Attend to major sickness Hearing loss Attend to hearing loss Better: Healthy people, with hearing loss Mood / less depression Emotional state Self-sufficiency Social relationships Hearing loss and hearing aids Life expectancy Dillon, NAL Longitudinal studies Better: + Social relationships Cognitive functioning Memory Hearing loss Learning ability Less depression Less paranoia Mulrow et al (1990); Dye & Peak (1983) Dillon, NAL Aged-care facilities Hearing loss Appearance of dementia Reduced auditory stimulation Cognitive decline Actual dementia ?? Improved services Improved quality of life Dillon, NAL 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 So why no increase in satisfaction? • Increase in laboratory-measured benefit • No increase in real-world reported satisfaction Marketing, hype, cost Technology advance Expectations increase Gap between performance and expectations - ?? Satisfaction? Performance increases (a little) Dillon, NAL 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 Moving on from prescriptions The trainable hearing aid Justin Zakis, Gitte Keidser, Hugh Mcdermott, Liz Convery Dillon, NAL Trainable aid – general structure Acoustic measurement module Learning algorithms User control(s) Programmable amplifier Dillon, NAL Aid user adjusts settings... Trainable Aid Dillon, NAL Aid user adjusts settings... Trainable Aid Dillon, NAL ...the hearing aid takes note Trainable Aid Dillon, NAL Process repeats for other sounds Trainable Aid Dillon, NAL After training, preferred settings are automatically applied... Trainable Aid Dillon, NAL After training, preferred settings are automatically applied... Trainable Aid Dillon, NAL After training, preferred settings are automatically applied... Trainable Aid Dillon, NAL After training, preferred settings are automatically applied... Trainable Aid Dillon, NAL Trainable aid philosophy Prescribe what can be prescribed, automatically and in minimum clinical time Leave the rest to the client (and the intelligence of the hearing aid) Fine tuning Dillon, NAL Training gain, CT, CR. 30 Gain Gain (dB) 25 20 CR 15 10 5 CT 0 30 40 50 60 70 80 90 Input level (dB SPL) Dillon, NAL Active occlusion reduction Jorge Mejia, John Coelho (deceased) Dillon, NAL Electronic Venting H/A C ∑ A Hearing Aid Canal B Cartilage Dillon, NAL Vent and amplification path transmission Directional mic Adaptive noise suppression 20 Insertion gain (dB) 15 Combined path 10 5 0 -5 -10 Amplified path Vent path -15 -20 125 250 500 1k 2k 4k 8k Frequency (Hz) Dillon, NAL Occlusion reduction: Mean and Standard Deviation Note that feedback gain was adjusted for all subjects, filter settings remain the same (22 ears) Dillon, NAL Super-directional hearing in noise Jorge Mejia Dillon, NAL Improving understanding in noise Wireless transmission √ √ √ Directional microphones √ √ (Adaptive noise suppression) Dillon, NAL Physical arrangement simulated 6 mm 6 mm Dillon, NAL Increase in SNR needed (dB) Loss of SNR in hearing loss 16 14 12 10 8 6 4 2 0 0 20 40 60 80 100 Hearing loss (dB) Dillon, NAL Blind source separation matrix (Inverse based on initial 100 ms of signal) Jorge Mejia Dillon, NAL The result ? • Hearing impaired people who can understand better in noise than people with normal hearing. Dillon, NAL 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 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 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 Aim To increase penetration rate of hearing aids and Increase usage and benefit Dillon, NAL The solution is in the hands of: • • • • • Clinicians Provider owners Government Manufacturers Researchers Dillon, NAL Clinicians Don’t fit people who don’t seem to want them Dillon, NAL Provider owners Provide incentives to clinicians for superior outcomes, not just superior sales Dillon, NAL 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 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 Government (cont) Outcomes measurement Just measure: – – – – Use Benefit Satisfaction Quality of life improvement International Outcomes Inventory for Hearing Aids Need to allow for: – New versus return clients – Response rate – Degree of hearing loss Dillon, NAL 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 Hearing device of the future • Pathway to many systems: Communication Information Entertainment • Speech enhancer in noise • Active hearing protector • (Hearing aid) Dillon, NAL Noise suppression Adaptive directionality Feedback cancelling Bernafon Oticon Phonak Siemens Starkey Dillon, NAL 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 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 Results from Telscreen Testing (n=4058) Golding, 2008 N=1270 N=1001 N=850 N=485 60.7% 38.7% >25 dB 4FAHL Worse ear (Wilson et al) N=230 27.7% N=124 N=36 24.8% 22.9% (N= 3996) (age range 16-100 years only) Dillon, NAL The life quality of people with hearing loss in the hands of: • • • • • Clinicians Provider owners Government Manufacturers Researchers Dillon, NAL Thanks for your attention Slides will be on the NAL web site www.nal.gov.au From May 28 Dillon, NAL