Download change - National Hearing Conservation Association

Otoacoustic Emissions in Monitoring NIHL
for Professional Musicians:
A 2-Year Follow-up Study
Annual NHCA Conference, 20 February 2016
Hilde Eising, MSc.
Hiske W. Helleman, MSc.
Prof. Wouter A. Dreschler
Academic Medical Centre, Amsterdam, The Netherlands
[email protected]
linical & Experimental
Audiology
Content

Professional musicians from 3 symphonic orchestras

2 years of (music) noise exposure

Audiometry

Otoacoustic emissions (OAEs)
linical & Experimental
Audiology
Content


Background
•
Otoacoustic emissions (OAEs)
•
Noise exposure in a symphonic orchestra
What do we know from literature?
•


OAEs versus audiometry
OAEs in monitoring NIHL for professional musicians:
•
Research questions
•
Preliminary results
Discussion
linical & Experimental
Audiology
Background - Noise induced hearing loss

Noise effects outer hair cells first

‘Noise notch’ around 4-6 kHz visible in
the audiogram

Often accompanied by tinnitus
linical & Experimental
Audiology
Background - Otoacoustic emissions (OAE)

Gives information about functioning of outer hair cells

Neonatal hearing screening (PASS / REFER)

Requires ‘clear’ signal above noise floor
speaker
microphone
linical & Experimental
Audiology
Background - Otoacoustic emissions (OAE)

Now: audiometry is gold standard

OAEs in occupational hearing programs?

Why OAEs?



Objective
?
?
Detect pre-clinical damage?
Fast
Easy to operate
Predict individual susceptibility to NIHL?
linical & Experimental
Audiology
Background – Noise exposure of musicians
~80 dB(A)
Average daily noise exposure:

~85 dB(A)
Depends on factors like
repertoire, arrangement,
acoustical circumstances,
conductor

Exceeds the European guidelines
for exposure to sound in a
professional environment
Source: ‘Onderzoek schadelijk geluid orkesten’, Peutz & Associés, 2003.
linical & Experimental
Audiology
~88 dB(A)
Background – Noise exposure of musicians

Audiograms show notches
•
Corrected for age and gender (ISO 7029)
Jansen E.J. et al 2009. Noise induced hearing loss and other hearing complaints among musicians of symphony orchestras. Int Arch
Occup Environ Health, 82, 2, 153–164.
linical & Experimental
Audiology
Background – Noise exposure of musicians

Audiograms show notches

Complaints about tinnitus (51%) and hyperacusis (79%)
•
More than could be expected
in the general population
Jansen E.J. et al 2009. Noise induced hearing loss and other hearing complaints among musicians of symphony orchestras. Int Arch
Occup Environ Health, 82, 2, 153–164.
linical & Experimental
Audiology
Background – Noise exposure of musicians

Audiograms show notches

Complaints about tinnitus (51%) and hyperacusis (79%)

Regular use of (mostly disposable) hearing protection during:
•
Orchestra repetitions: 52%
•
Concerts: 29%
Jansen E.J. et al 2009. Noise induced hearing loss and other hearing complaints among musicians of symphony orchestras. Int Arch
Occup Environ Health, 82, 2, 153–164.
linical & Experimental
Audiology
OAEs: What do we know from literature?

Longitudinal studies
•
No clear relation between changes in audiometry and OAE

•
e.g. Moukos et al. 2014, Helleman et al. 2012, Marshall et al. 2009, Lapsley-Miller et al. 2006
Low-level, absent or abnormal OAEs might indicate an increased
risk of future NIHL

Lapsley-Miller et al. 2006, Shupak et al. 2007, Duvdevany et al. 2007, Job et al. 2009, Marshall et
al. 2009
linical & Experimental
Audiology
In progress: systematic literature review

Why? Limited amount of longitudinal studies

Published literature is inconsistent

•
Study duration
•
OAE stimulus parameters
•
Study population
•
…
However, OAEs are promoted in occupational health programs..
 ‘Otoacoustic emissions: a new gold standard for early detection of hearing loss’
linical & Experimental
Audiology
In progress: systematic literature review
Duplicates
removed

Inclusion criteria
•
Subjects exposed to noise
•
OAE and audiometry measured at baseline
639
abstracts
screened
525
excluded
114
full text
screened
63
excluded
and at least 1 follow-up

‘long term effects’
(permanent threshold shifts, PTS)

51
included
In review
‘short term effects’
(temporary threshold shifts, TTS)
Prospero registration nr.: CRD42015027111
linical & Experimental
Audiology
14
‘long-term’
effects
37
‘short-term’
effects
Otoacoustic Emissions in Monitoring NIHL for
Professional Musicians:
A 2-Year Follow-up Study
Work in progress
linical & Experimental
Audiology
Method


60 professional musicians from 3 symphonic orchestras
•
34 Male, 26 Female
•
Median age: 42, range 24-64
2 measurements, ~2 years apart
•
Baseline
•
Follow-up

Audiometry (250 Hz - 8 kHz), air conduction

TEOAE (5 frequency bands: 1-4 kHz)

DPOAE (27 frequencies: 0.8-8 kHz, 1/8 oct)

Tympanometry / otoscopic inspection

All tests performed at audiological department of AMC
linical & Experimental
Audiology
Research questions
1. Is the effect of approximately two years of noise (music) exposure
measurable using audiometry, TEOAE and DPOAE
2. Are individual cases of noise induced audiometric threshold shift associated
with emission shift?
3. Are we able to predict which persons have increased risk of future hearing
loss based on initial OAEs?
linical & Experimental
Audiology
Research questions
1. Is the effect of approximately two years of noise (music) exposure
measurable using audiometry, TEOAE and DPOAE
2. Are individual cases of noise induced audiometric threshold shift associated
with emission shift?
3. Are we able to predict which persons have increased risk of future hearing
loss based on initial OAEs?
linical & Experimental
Audiology
Preliminary remark
How you usually look at an audiogram
linical & Experimental
Audiology
Preliminary remark
How you usually look at an audiogram
linical & Experimental
Audiology
Preliminary remark
How I will show you this audiogram today
linical & Experimental
Audiology
Mean results at baseline – right versus left
Right
Left
At baseline:
• Audiometry: the left ear is slightly worse than right at high frequencies
linical & Experimental
Audiology
Mean results at baseline – right versus left
Right
Left
At baseline:
• Audiometry: the left ear is slightly worse than right at high frequencies
• OAEs: left ear has lower amplitudes in mid frequencies
linical & Experimental
Audiology
Mean results at baseline and follow-up
Baseline
Follow-up
Group results show changes in audiometry, TEOAE and DPOAE
linical & Experimental
Audiology
Mean change – group
Change
Deterioration
Audiometry
-Overall trend decrease
-Deterioration mostly at 4-8
kHz
TEOAE
-Deterioration at mid
frequencies (~2 kHz)
DPOAE
-Deterioration mid
frequencies (~2-4 kHz)
-Improvement low/high
Audiometry compared to OAE: different frequency area
linical & Experimental
Audiology
Research questions
1. Is the effect of approximately two years of noise (music) exposure
measurable using audiometry, TEOAE and DPOAE
2. Are individual cases of noise induced audiometric threshold shift associated
with emission shift?
3. Are we able to predict which persons have increased risk of future hearing
loss based on initial OAEs?
linical & Experimental
Audiology
Threshold shift versus emission shift
Audiometry
Shift

Audiometry: 4-6 kHz

TEOAE: overall

Relation between threshold
shift and emission shift?
linical & Experimental
Audiology
TEOAE
Threshold shift versus emission shift
linical & Experimental
Audiology
TS-
No TS-
Threshold shift versus emission shift
linical & Experimental
Audiology
Threshold shift versus emission shift
TS-
No TS-
ES-
linical & Experimental
Audiology
No ES-
Threshold shift versus emission shift
No TS-
ES-
No ES-
TS- & ES-
linical & Experimental
Audiology
TS-
No TS-
No ES-
Threshold shift versus emission shift
ES-
sensitivity
of OAE’s?
No TS-
Enhanced
No ES-
TS- & ES-
linical & Experimental
Audiology
TS-
No TS-
No ES-
Threshold shift versus emission shift
ES-
No ES-
sensitivity
of OAE’s?
No TS-
Enhanced
Were OAEs
already
decreased?
No ES-
TS- & ES-
linical & Experimental
Audiology
TS-
No TS-
Threshold shift versus emission shift
Overall observations:

Small number of
threshold or emission
shifts

No clear relation
between changes in
audiometry and OAE
linical & Experimental
Audiology
Threshold shift versus emission shift
No TS-
ES-
TS-
Predict?
linical & Experimental
Audiology
No ES-
Research questions
1. Is the effect of approximately two years of noise (music) exposure
measurable using audiometry, TEOAE and DPOAE
2. Are individual cases of noise induced audiometric threshold shift associated
with emission shift?
3. Are we able to predict which persons have increased risk of future hearing
loss based on initial OAEs?
linical & Experimental
Audiology
Individual threshold shifts

How to define individual threshold shift?
linical & Experimental
Audiology
Individual threshold shifts
Two groups:

‘Change’.
linical & Experimental
Audiology
Mean age: 42 (range 24-64).
Change
N=17
Right
Left
Total
N=10
N=7
N=17
Individual threshold shifts
Two groups:

‘Change’.
Mean age: 42 (range 24-64).
N=17

‘No change’.
Mean age: 46 (range 32-64).
N=103
linical & Experimental
Audiology
Right
Left
Total
Change
N=10
N=7
N=17
No change
N=50
N=53
N=103
‘No change’ – shift
linical & Experimental
Audiology
Right
Left
Total
Change
N=10
N=7
N=17
No change
N=50
N=53
N=103
‘Change’ versus ‘No Change’ – shift
Audiometry:
•
Clear difference
between groups
TEOAE

Largest shift
~2 kHz
DPOAE

Largest shift 2.5 6 kHz.

Very low and high
frequencies less
reliable
linical & Experimental
Audiology
Right
Left
Total
Change
N=10
N=7
N=17
No change
N=50
N=53
N=103
‘Change’ versus ‘No Change’ – at baseline
Did these groups differ at baseline?
linical & Experimental
Audiology
Right
Left
Total
Change
N=10
N=7
N=17
No change
N=50
N=53
N=103
‘Change’ versus ‘No Change’ – at baseline
Audiometry:
•
No difference
between groups
linical & Experimental
Audiology
Right
Left
Total
Change
N=10
N=7
N=17
No change
N=50
N=53
N=103
‘Change’ versus ‘No Change’ – at baseline
Audiometry:
•
No difference
between groups
OAEs
•
‘Change group’
shows higher
amplitudes ~12.5 kHz and lower
amplitudes in high
frequency range.
•
Different ‘shape’
of OAE amplitude
spectra
linical & Experimental
Audiology
Right
Left
Total
Change
N=10
N=7
N=17
No change
N=50
N=53
N=103
Take home messages
1.
2.
3.
Group results
•
Small but consistent differences between baseline and follow-up
•
OAEs show changes in other frequency area than PTA
Individual results
•
Small number of ears with emission shift or threshold shift
•
No clear relation between emission shift and threshold shift
Predictive value
•
We observe intriguing differences in baseline OAEs when comparing groups
of ears with and without threshold shift
•
Future (statistical) analysis will clarify whether OAEs have a predictive value
in individual cases of NIHL
linical & Experimental
Audiology
Acknowledgements


The participants from 5 Dutch symphonic orchestras
•
Koninklijk Concertgebouworkest
•
Nederlands Philharmonisch Orkest
•
Holland Symfonia
•
Het Gelders Orkest
•
Residentie Orkest
Colleagues at AMC
linical & Experimental
Audiology
Thank you for you attention!
Questions?
linical & Experimental
Audiology
Hilde Eising, MSc.
[email protected]
Method



Audiometry
•
Interacoustics AC40 audiometer with TDH39 headphones
•
Calibrated according to ISO 389
•
Sound–isolated booth
TEOAE (Otodynamics ILO 292)
•
80 dB SPL click
•
Non-linear
•
Half-octave frequency band (1, 1.5, 2, 4 and 4 kHz)
DPOAE (Otodynamics ILO 292)
•
L1=75 dB SPL, L2=70 dB SPL

at follow-up also L1=65 dB SPL and L2=55 dB SPL
•
f2/f1=1.22
•
Measured at 27 f2 frequencies (815 to 8000 Hz)
•
(8 points per octave)
linical & Experimental
Audiology
Statistical analysis

Goal: to describe the observed effects in a correct way

Linear mixed effects model
•
Controlling for ear, age, gender, hearing threshold at baseline
linical & Experimental
Audiology
OAEs: What do we know from literature?

Cross-sectional studies
•
Lower OAE levels associated with poorer audiometric thresholds

•
e.g. Attias et al. 2001, Mansfield et al. 1999
Noise exposed people have lower OAE amplitudes than non-exposed
people with similar audiometric thresholds

e.g. Murray et al. 1993, Attias et al. 2001, Desai et al. 1999
 What are ‘similar thresholds’?
linical & Experimental
Audiology
‘Change’ versus ‘No Change’ – at follow-up
linical & Experimental
Audiology
Right
Left
Total
Change
N=10
N=7
N=17
No change
N=50
N=53
N=103
Mean results baseline – male versus female
Male
Female
•
Male: better thresholds <3 kHz.
•
Female: generally higher OAE amplitudes
linical & Experimental
Audiology
Only NH ears - baseline
No change
Change
Total
NH
N=62
N=20
N=82
linical & Experimental
Rest
N=28
N=10
N=38
Audiology
Total
N=90
N=30
N=120
Only NH ears - change
linical & Experimental
Audiology
Case study – patient nr. 58531
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Audiology