Effects of hearing loss and hearing aids on quality of life and cognitive decline Harvey Dillon, Gitte Keidser National Acoustic Laboratories and The Hearing Cooperative Research Centre Better Hearing National Conference 2013

Impact of untreated hearing loss on health Proven links between hearing loss and : –depression / mood / emotional state –social isolation, loneliness, withdrawal –self-sufficiency –cognitive ability –physical and psychological well-being –life expectancy anger / irritation distress / fear embarrassment unemployment restricted travel Asserted links between hearing loss and: anxiety paranoia exhaustion insecurity loss of group affiliation loss of intimacy

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

Effects of hearing aids? Hearing loss MortalityDepression Isolation Anxiety Insecurity etc

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

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 (internal locus of control) Fatalistic people (external locus of control)

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

Hearing loss, hearing aids and cognitive decline

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

Longitudinal study: Lin et al (2013) Johns Hopkins Centre, USA Sample 1,984 adults, mean age =77 years, no dementia 58% had hearing loss (>25 dB 4FA in better ear) Cognitive ability measured 6 years later Results Those with hearing loss had rate of cognitive decline 37% greater than those with no loss Rate of decline increased significantly with hearing loss Rate of decline much less for those with hearing aids, but difference not statistically significant & not randomised –Adjusted for age, sex, race, education, smoking status, hypertension, diabetes mellitus, stroke history –Cause and effect likely but not proven

Rate of cognitive decline per year Effect of hearing loss on cognitive decline

Rate of cognitive decline per year * * Beneficial effect of hearing aids

Effects of hearing loss Hearing loss Poor speech understanding Isolation Something else Poor Working memory Cognitive decline, dementia

UK Biobank Extensive data on over 100,000 people Aged 40 to 69 years Relation of hearing loss to other factors being analysed by Dr Keidser at NAL Attempting to investigate path from hearing loss to depression and cognitive abilities by statistical methods

UK Biobank data No hearing loss Hearing loss

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

Hearing loss in the future

Why do people hear but not understand? ….. and what NAL is doing about it

Good Noise damaged

What can go wrong? The hair cells can die (noise, drugs, age)

Sound level First formant oo Frequency (Hz) ee Second formant Vowel spectra and audibility

Intense Moderate Weak Too loud Too soft Norm (a) Sam Intense Moderate Weak Too loud Too soft (b) Intense Moderate Weak Too loud Too soft (c) Reduced dynamic range with hearing loss

Prescribing hearing aids to maximise intelligibility and control loudness NAL-NL2 (2011) NAL-NL1 (1999) NAL-RP (1991) NAL-R (1986) NAL (1976)

But hearing is still not normal!

Sound level (a) Frequency (Hz) Excitation (b) Frequency resolution in hearing loss

NAL binaural beamformer  + + Front Left Right Delay Beamformer and DOA  HRTF DOA Right Left + + Super-directional microphones To end To CAPD Mejia

Outcomes of children with hearing impairment Teresa YC Ching, and team

We measure outcomes as children grow, …

creating sound value TM Outcomes Expressive Communication Auditory comprehension Receptive vocab. Expressive vocab. Language Articulation Phonological dev Speech perception Spatial release from masking Speech Reading Writing Math reasoning Numerical operations Literacy & numeracy Aural-oral function in real life Pragmatics Strengths and difficulties Psycho- social skills Educational attainment Employment Education & employment T Ching, NAL, HEARing CRC

creating sound value TM T Ching, NAL, HEARing CRC At 5 years, early CI linked to better outcomes (n = 104)

35 So baby, how does it sound? Objective hearing aid evaluation for: young infants difficult-to-test people

HearLab

Hearing disorders in the brain Frontal lobe Temporal lobe Superior temporal gyrus Occipital lobe Parietal lobe Sylvian fissure

Spatial Processing Disorder Noise Speech Lack of spatial release from masking Cameron, Dillon & Newall

LISN & Learn Game Target at 0˚: Distracters at + and -90˚:

Target: The horse kicked six wet shoes

LiSN & Learn - Performance Over Time (n=9) LiSN & Learn SRT (dB) 10 dB Better Cameron & Dillon (2011)

Randomized Control Trial Earobics Lisn & Learn N = 5 Cameron, Glyde & Dillon (2012)

Future research Central processing disorders in elderly people Blue Mountains Study: Golding et al (2004) Studied 1576 people > 55 years Battery of 7 tests 76% failed 1 or more tests 64% failed 2 or more tests But can we give training to overcome it?

Thanks for listening NAL is funded by the Federal Department of Health, Office of Hearing Services. Volunteers needed !