Restoring spatial hearing:
Cochlear implants for
single-sided deafness
Joshua Bernstein, Ph.D.
Research Audiologist
National Military Audiology and Speech Pathology Center
Walter Reed National Military Medical Center
USUHS State of the Science Symposium – 17 April 2015
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Acknowledgements
• Collaborators/Contributors
Walter Reed
Joshua Bernstein
Jerry Schuchman
Arnaldo Rivera
Doug Brungart
Kia Brooks
Ben Sheffield
Julie Cohen
Tom Heil
U Maryland – College Park
Matt Goupell
Jessica Wess
Wright-Patterson AFB (OH)
Nandini Iyer
Eric Thompson
Melissa Theis
Madigan Army Medical Center (WA)
Kate Marshall
Jim Crawford
The views expressed in this presentation are those of the authors and do not
reflect the official policy of the Departments of the Army/Navy/Air Force,
Department of Defense, or U.S. Government.
USUHS State of the Science Symposium – 17 April 2015
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Binaural hearing
Your hearing benefits
greatly from having
two ears….
-Better-Ear Advantage
-Localization
-Noise Suppression (MLD)
-Reverberation Suppression
USUHS State of the Science Symposium – 17 April 2015
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Military importance of having two
ears
Speech communication in
noisy environments
USUHS State of the Science Symposium – 17 April 2015
Localization
4
Single-sided deafness (SSD)
• One deaf ear
• Not an uncommon problem
– Approximately 1% of the population will acquire SSD in their adult life
(estimate based on Baguley et al, 2006)
• Common etiologies
–
–
–
–
–
Sudden sensorineural hearing loss (idiopathic, probably viral)
Meniere’s Disease
Vestibular schwannoma
Complications from middle-ear surgery
NOT blast exposure
• Military fitness for duty
– Retention policy depends on the service
USUHS State of the Science Symposium – 17 April 2015
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Treatment options for single-sided
deafness
1) Do nothing
2) Contralateral routing of signal (CROS)
hearing aid
3) Bone-anchored hearing aid (BAHA)
4) Cochlear implant (CI)
Images: Advisory Group for Single-Sided Deafness (2003).
USUHS State of the Science Symposium – 17 April 2015
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Cochlear implants for single-sided
deafness (SSD)
• New treatment option for one deaf ear
• Can aid speech reception in spatial noise; localization (Vermeire &
Van de Heyning, 2009; Buechner et al., 2010; Arndt et al., 2011; Firzst et al., 2012)
• Previously reported speech-in-noise benefits can be
attributed to better ear listening
X = Deaf/CI ear
Speech
Noise
Speech
X
No CI benefit

Noise
X
No CI benefit
Noise

USUHS State of the Science Symposium – 17 April 2015
X
CI benefit
Speech

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Can a CI restore spatial hearing?
• Normal binaural hearing assists listening in complex auditory
environments
• Segregate/separate
• Localize
• Attend
• Can a CI assist individuals
with SSD in such environments?
USUHS State of the Science Symposium – 17 April 2015
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Possible advantages of a CI for SSD in
multisource environments
Experiment 1:
Concurrent speech-stream segregation
Experiment 2:
Localization in a multisource environment
Participants:
Eight individuals with SSD who have received
a cochlear implant
USUHS State of the Science Symposium – 17 April 2015
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Experiment 1: Spatial release from
masking
Condition: NH/Deaf
Maskers
Target
X
READY RINGO GO TO GREEN 2 NOW
READY BARON GO TO RED 4 NOW
READY ARROW GO TO BLUE 8 NOW
USUHS State of the Science Symposium – 17 April 2015
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Experiment 1: Spatial release from
masking
Condition: NH/NH
Maskers
Target
READY RINGO GO TO GREEN 2 NOW
READY BARON GO TO RED 4 NOW
READY ARROW GO TO BLUE 8 NOW
READY RINGO GO TO GREEN 2 NOW READY RINGO GO TO GREEN 2 NOW
READY ARROW GO TO BLUE 8 NOW
USUHS State of the Science Symposium – 17 April 2015
READY ARROW GO TO BLUE 8 NOW
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Experiment 1: Spatial release from
masking
Condition: NH/Deaf
Maskers
Target
X
READY RINGO GO TO GREEN 2 NOW
READY BARON GO TO RED 4 NOW
READY ARROW GO TO BLUE 8 NOW
USUHS State of the Science Symposium – 17 April 2015
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Experiment 1: Spatial release from
masking
Condition: NH/CI
Maskers
Target
READY RINGO
READY
GORINGO
TO GREEN
GO TO
2 NOW
GREENREADY
2 NOW
RINGO GO TO GREEN
READY2 RINGO
NOW GO TO
READY
GREEN
RINGO
2 NOW
GO TO GREEN 2 NOW
READY BARON GO TO RED 4 NOW
READY ARROW
READYGO
ARROW
TO BLUE
GO8TO
NOW
BLUEREADY
8 NOWARROW GO TO BLUE
READY
8 NOW
ARROW GO READY
TO BLUE
ARROW
8 NOWGO TO BLUE 8 NOW
USUHS State of the Science Symposium – 17 April 2015
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The CI provides masking release
Masker(s)
One samegender
Two samegender
One oppositegender
Two oppositegender
Noise
Presenting the maskers to the CI improved performance in
multitalker situations
USUHS State of the Science Symposium – 17 April 2015
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Experiment 2: Multisource localization
26-loudspeaker array
Environmental sounds (e.g.
toothbrushing, sheep, siren)
Condition Target source to
localize
Total #
of
sounds
Target
duration
(sec)
Localize
Only sound
1
2
Add
New sound added to 2 or 4
mixture after 6s
4
Remove
One sound removed
from mixture after
6s
4
2 or 4
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The CI improves localization
accuracy
Turning on the CI decreased the localization error
in all 3 conditions
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The CI reduces the physical
effort required for localization
- The CI decreased the amount of head turning
during the localization task
- Even in the “add” condition while the listener was
just waiting for the new target sound to appear
USUHS State of the Science Symposium – 17 April 2015
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Planned FDA clinical trial (Industry partner)
Enrollment and
Initial Testing
Initial
Assessment
Choses Treatment
Group
No
treatment
CROS
BAHA
Cochlear
Implant
USUHS State of the Science Symposium – 17 April 2015
Follow-up
appointments
Localization
Speech in noise
Tinnitus
Subjective Questionnnaires
0
6
12
18 24
months out from receiving
treatment
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Conclusions
• Having two ears is important for listening in complex auditory
scenes
• Cochlear implants have the potential to rehabilitate some
binaural hearing functions for individuals with SSD:
– Separating simultaneous voices
– Improved localization accuracy and a reduced need for head movement
USUHS State of the Science Symposium – 17 April 2015
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