Download The Importance of Binaural Hearing

International Hearing Society
60th Annual Convention & Expo
September 15-17, 2011
The Importance of Binaural
Hearing
Theodore Mason, M.D.
Springfield, Massachusetts
September 17, 2011
Presentation Overview
•
•
•
•
Definition of Terms
Importance of Binaural Hearing
Bilateral Hearing with Hearing Aids
Implantable Hearing Solutions
– Bimodal Hearing
– Bilateral Hearing
• Candidacy Criteria
• Clinical Management
• Summary
Bimodal use is on the rise
Rationale for bimodal fittings:
• Expanding candidacy criteria
• Improved CI
technology/performance
• Improved power aids w/ DSP +
feedback cancellation
Potential benefits:
• Better hearing performance in
background noise¹
• Music appreciation²
1. Tyler, R, et al. (2002) Patients utilizing a hearing aid and a cochlear implant: Speech perception and localization. Ear Hear, 23:98-105.
2. Sucher, C., McDermott, H. (2009) Bimodal stimulation: Benefits for Music Perception and Sound Quality. Coch Impl Intl, 10 (Suppl.1): 96-99.
Bilateral is a consideration
• 5% of adults who qualified for cochlear
implantation and pursued treatment were
bilaterally implanted
1
– Based upon internal data of three
manufacturers
– 36,398 pursued unilateral and 1,882 pursued
bilateral
1. Peters et al (2010). Worldwide Trends in Bilateral Cochlear Implantation. Laryngoscope Supplement, 120; S17-S44.
Definition of Terms
A Few Terms Explained
• Bilateral: Both ears
• Bilateral cochlear implantation: CIs placed
in each cochlea of an individual patient
• Bimodal: Two different modes of stimulation
• Bimodal Hearing/Bimodal Devices: CI in
one ear, Hearing Aid (HA) on the other ear
• Binaural Hearing/Binaural Processing*:
Integration in the central auditory pathways of
bilateral sound input
* A CI and an optimally fitted HA on the non-implanted ear, two
normally hearing ears, two hearing aids, or two CIs can provide
binaural processing for some patients.
A Few Terms Explained
Bilateral
Cochlear
Implants
Bimodal
Binaural
Hearing/
Processing
Side One
Side Two
Cochlear Implant
Cochlear Implant
Cochlear Implant
Hearing Aid
Cochlear Implant or
Hearing Aid may
provide binaural
processing
Cochlear Implant
or
Hearing Aid may
provide binaural
processing
*Binaural Hearing assumes processing of two
signals throughout the central auditory system
Cochlear Implant Candidacy
Criteria
Adult Candidacy Criteria
• Adults: Individuals 18 years of age or older who have bilateral
sensorineural hearing impairment and obtain limited benefit from
appropriate binaural hearing aids.
• These individuals typically have moderate to profound hearing loss in
the low frequencies and profound (≥ 90 dB HL) hearing loss in the
mid to high speech frequencies.
• Limited benefit from amplification is defined by test scores of 50%
correct or less in the ear to be implanted (60% or less in the bestaided listening condition) on tape-recorded tests of open set sentence
recognition
Evolution of Adult Candidacy Criteria
1985
1990
1998 (CI24M)
2000 (CI24R/CA ) to
Current (CI512)
ONSET of
Postlinguistic Postlinguistic Pre &
Hearing Loss
Postlinguistic
Pre & Postlinguistic
DEGREE of
SNHL
Profound
ADULT Open- 0%
set sentences
Profound
Severe-Profound
Moderate-to-profound
-bilateral sensorineural
hearing loss
0%
40% or less
< 50% sentence
recognition in ear to be
implanted (aided)
< 60% in contralateral
ear and binaurally (aided)
Adult Candidacy Criteria
Audiometric candidacy ranges
Moderate-to-profound SNHL in both ears
Speech recognition criteria
Limited benefit from
amplification defined as
preoperative test scores:
<50% sentences in ear to be
implanted
<60% bilaterally (best aided
condition)
Medicare criteria differs slightly:
≤ 40% sentence recognition in
the ear to be implanted (aided)
Case Study
52 y.o. CI – Right Ear
Pre-op
Aided Scores*
HINT
12%
CUNY
19%
CNC
0%
Post CI
Scores
HINT
87%
CUNY
92%
CNC
78%
A - best aided
C - CI right ear
*Performed in best aided condition
Note: Left side is dead ear
The Importance of Binaural
Hearing
What is Binaural Hearing?
•
Inputs from each ear travel up
ipsilateral and contralateral brainstem
pathways where the 2 inputs are
compared and processed at various
nuclei before reaching the auditory
cortex.
•
Binaural hearing allows the listener to
take advantage of a variety of auditory
cues such as interaural level and time
differences that result in specific
benefits.
Potential Benefits of Binaural Hearing
•
Improved speech perception in quiet and in noise,
from:
– Binaural redundancy/summation effects
– Spatial separation (binaural squelch and head
shadow effects)
• Improved sound localization
• Improved:
– Ease of listening,
– Perceived benefit and satisfaction
– Quality of life
Measured Effects of Binaural Hearing
•
Head Shadow Effect is a physical phenomenon
– This occurs when the head obstructs sounds arriving at the ears from
different locations. Binaural hearing allows the listener to always have
available the ear with the better signal-to-noise ratio (SNR)
•
Binaural Redundancy and Binaural Squelch Effects are products of
central auditory processing
– These occur when inputs from both ears are analyzed throughout the
auditory pathways
– These are signs of the ability of the auditory nervous system to
integrate, fuse, and use information from the two ears
– In effect helps the brain “tease out” the desired auditory signal from the
background noise
Head Shadow Effect
• Using the ear with the better SNR in spatially
separated speech and noise
• With one implant or hearing in only one ear in certain listening situations
the implanted ear or hearing ear may have the less favorable SNR
• Spatial separation benefits can occur from the head shadow effect and
having 2 functioning cochleae
Sound arrives later and softer
Sound arrives earlier
and louder
Head Shadow Effect
Speech
Listening using the
ear with the better
SNR to improve
performance
Noise
• Large and robust benefit of
head shadow1
1. Litovsky et al (2006). Simultaneous bilateral implantation in adults: a multicenter clinical study. Ear Hear. 27(6):714-31.
Binaural Redundancy Effect
• Simply means two ears are better than
one when speech or speech in noise are
from the same location, because each ear
receives the same input
• Several studies have shown a significant
binaural summation (redundancy) effect for
understanding words and sentences
compared to listening with either cochlear
implant alone1,2
1. Litovsky, R, et al. (2006). Simultaneous bilateral cochlear implantation in adults: A multicenter clinical study. Ear Hear, 27(6), 714-731.
2. Dunn, C, et al. (2008). Comparison of speech recognition and localization performance in bilateral and unilateral cochlear implant users
matched on duration of deafness and age at implantation. Ear Hear, 29(3): 352-359.
Binaural Redundancy Effect
•
Auditory system’s ability to use
redundant information for better
performance when the same signal
arrives at both ears
•
Difference between bilateral and
better ear performance in spatially
coincident speech, or speech and
noise
Speech
and Noise
Binaural Squelch
Advantage of adding the
ear with the poorer SNR
compared to listening with
the better SNR ear alone
• Buss et al (2008) saw
emergence of binaural
Noise
squelch effect in some
subjects between the 6 and 12
mo test intervals, with a highly
significant mean increase in
magnitude of the advantage,
Poorer SNR
1
from 3.3% to 10.6%
Speech
Better SNR
1. Buss, E, et al. (2008). Multicenter U.S. bilateral Med-El cochlear implantation study: Speech perception over the first year of use. Ear Hear,
29(1): 20–32.
Bilateral Hearing with
Hearing Aids
Bilateral Hearing
• Bilateral hearing refers to the ability to
receive a signal on two sides, this can be
achieved using:
– Two normally hearing ears
– Two hearing aids or Baha® devices
– A cochlear implant and a hearing aid (bimodal
hearing)
– Two cochlear implants
Bilateral Hearing with Hearing
Aids
• In 1990 Vanderbilt University and the Department of Veterans
Affairs cosponsored a conference designed to address current
clinical and research issues on hearing aids
• Following the conference, a consensus statement was developed on
hearing aid selection procedures for adults.
• “Unless clear contraindications exist, binaural hearing aids
should be considered the preferred fitting for the prospective
hearing aid user.1”
– Bilateral hearing aid fittings have been standard practice in the
hearing aid industry for years!
1. Hawkins, DB et al. Vanderbilt/VA Hearing Aid Conference 1990 Consensus Statement. ASHA 1991, 37-38.
Bilateral Hearing with Hearing
Aids
•
•
For patients with bilateral hearing loss, bilateral hearing aid fittings have
been the standard practice for many years
Reasons for bilateral hearing aid fittings include1:
– Better understanding of speech
– Better understanding in group and noisy situations
– Better ability to tell the direction of sound
– Better sound quality
– Wider hearing range
– Better sound identification
– Keep both ears active resulting in potentially less hearing loss
deterioration
– Hearing is less tiring and listening more pleasant
– Feeling of balanced hearing
– Consumer preference
– Customer satisfaction
1. As reported by the Better Hearing Institute, http://www.betterhearing.org/hearing_solutions/binaural.cfm?printfriendly=1
Determining the binaural hearing solution
• We know that Two Ears
ARE Better Than One
– This may mean different things
for different individuals. It could
mean:
• Using two hearing aids/Bahas®
• Using a cochlear implant and a
hearing aid
• Using two cochlear implants
How do you
determine
which
scenario is
best for each
patient?
Clinical Considerations
Bimodal
Hearing Aid & CI
Bilateral
CI
Bilateral
Hearing Aid
Binaural Hearing
Solution
Unilateral
Hearing Aid
Unilateral
Hearing Aid
Why only one hearing solution?
Implantable Hearing
Solutions
More potential for Bimodal users than you think
• Severe to profound hearing loss in the US
8.4 million Hearing Aid (HA) users in
U.S.1
8.4m
~840,000 severe to profound 2 (10%)
840k
~523,000 potential
523k
cochlear implant candidates3
1. Kochkin, S. (2009) MarkeTrak VIII: 25 Year Trends in the Hearing Health Market. The Hearing Review, October.
2. Blanchfield, B.B., et. Al. (2001). The severely to profoundly hearing-impaired population in the United States: Prevalence estimates and demographics. JAAA. 12, 183-189.
3. Cochlear internal estimates.
Bimodal versus Bilateral:
Candidacy Considerations
• Current status
– Unanimous agreement by panel that bilateral implantation
provided improved auditory perception in the majority of
cases1
• When to consider bimodal devices?2
– Residual hearing in the non-implanted ear
– Good HA performance in that ear
– When there is any possibility of benefit
• When to consider bilateral implantation?
– Little or no residual hearing in non-implant ear
– No significant benefit, or even a decrement in performance,
from hearing aid use in the non-implant ear
1. Consensus on auditory implants. 2007. June 14-16, 2007, Marseille France.
2. Offeciers, E, et al. (2005). International consensus on bilateral cochlear implants and bimodal stimulation. Acta Oto-Laryngol, 125: 918-919.
Bimodal Hearing:
More Common Today
• Broadened indications for implant candidacy:
more individuals with potentially useable
residual hearing
– 80% (42 of 53) used bimodal hearing for >8
hours on average and all rated the bimodal
condition superior to CI alone1
– 60% (15 of 24) of bimodal users report
using hearing aid more than 50% of the
time2
• Reviews of existing literature support fitting of a
contralateral hearing aid as the first line of
treatment to CI recipients with residual hearing3,4
1.
2.
3.
4.
Cowan, R, Chin-Lenn,J. (2004). Pattern and prevalence of hearing aid use post implantation in adult cochlear implant users. Aust NZ J Audiol Suppl : 48.
Fitzpatrick, et al. (2009). Users experience of a cochlear implant combined with a hearing aid. Intl J Audioloogy, 48, 172-182.
Schafer EC et al. (2007). A meta-analytic comparison of binaural benefits between bilateral cochlear implants and bimodal stimulation. J Am Acad Audiol. Oct;18(9):760-76.
Ching et al (2007). Binaural-Bimodal Fitting or Bilateral Implantation for Managing Severe to Profound Deafness: A Review. Trends in Amplification, Vol. 11, No. 3, 161-192
Potential Advantages of Bimodal Hearing1,2
• Localization and spatial hearing
• Interaural time, intensity, phase differences at the 2 ears
• Complimentary cues
• Combining low-frequency information from the hearing aid
with high-frequency information from the implant can help,
for example by separating voices in noise
• Sound quality, music perception and enjoyment
• Improved quality by adding fundamental frequency,
acoustic pitch and fine temporal structure not available
through current cochlear implants
1. Ching et al (2007). Binaural-Bimodal Fitting or Bilateral Implantation for Managing Severe to Profound Deafness: A Review. Trends in
Amplification, Vol. 11, No. 3, 161-192.
2. Fitzpatrick, et al. (2009). Users experience of a cochlear implant combined with a hearing aid. Intl J Audiology, 48, 172-182.
Bimodal Speech Recognition
•
•
•
1
19 Nucleus 24 recipients using a well-fit digital HA on the contralateral ear
Test measures: roaming speech recognition task and localization
– Stimuli: CNC words presented at a roving level of 60 dB SPL (+/- 3 dB),
presented randomly from an array of 10 loudspeakers
– Subjects cued with “ready” and allowed to turn toward the loud speaker prior to
repeating the stimulus word
– Localization: subject identified the loud speaker location by speaker number
– Conditions: HA, CI and CI+HA
Mean speech recognition results
– HA = 12% words, 37% phonemes
– CI = 39% words, 66% phonemes
– CI+HA = 53% words, 76% phonemes
– Conditions were significantly different from each other for both words and
phonemes
– No subject performed poorer with CI+HA than either monaural condition
1. Potts et al. (2009) Recognition and localization of speech by adult cochlear implant recipients wearing a digital hearing aid in the
nonimplanted ear (bimodal hearing) J Am Acad Audiol. 2009 Jun;20(6):353-73.
Case Study
36 y.o. CI Right Ear + HA Left Ear
Pre-op best aided
R
L
AU
WRS %
0
32
36
HINT-Q*
%
0
50
50
RCI
LHA
AU
WRS %
80
32
dnt
HINT-Q*
%
92
48
100
HINT-N#
CI+HA
80
dnt
100
Post-op (6 mos)
*60dB SPL #+10/SNR
dnt = did not test
A – Aided SF
C - CI right ear
Bimodal Localization
1
• Localization abilities reported as RMS error
– HA = 61° error
– CI = 54° error
– CI+HA = 39° error
• CI+HA localization was significantly better than either
monaural condition
• The HA and CI conditions were not significantly
different
• Important to maximize audibility with HA through 2 kHz
1. Potts et al. (2009) Recognition and localization of speech by adult cochlear implant recipients wearing a digital hearing aid in the
nonimplanted ear (bimodal hearing) J Am Acad Audiol. 2009 Jun;20(6):353-73.
Bimodal Sound Quality and Music Perception
•
In general implant recipients perform poorly on tests
of pitch perception and melody recognition1
•
In a study of Music Perception in Nucleus® CI Users:
– Bimodal users performed significantly better on all
tests than those using only electrical stimulation2
•
Comparison of CI and CI+HA on familiar melody
recognition show the majority of recipients had
significant improvements in the CI+HA condition3
– Some data suggesting amount of benefit is related
to amount of contralateral residual hearing
1. Gfeller, K (2007). Accuracy of Cochlear Implant Recipients on Pitch Perception, Melody Recognition, and Speech Reception in Noise. Ear and
Hearing; 28(3).
2. Cochlear Americas Multicenter Study on the Evaluation of the UW-CAMP Music Test, 2007 [data on file]. Lane Cove, Australia: Cochlear Ltd.
3. El Fata F et al. (2009). How much residual hearing is 'useful' for music perception with cochlear implants? Audiol Neurootol;14 Suppl 1:14-21.
When to Move from Bimodal to Bilateral CIs?
•
Unilateral implant recipients who attempt but
discontinue hearing aid use in the contralateral ear
– <25% of 72 unilateral implant recipients with
residual hearing (PTA <110 dB) used their hearing
aid more than 50% of the time1
– 40% of implant recipients with a PTA of < 100 dB
reported consistent hearing aid use 1
•
Documented lack of improvement or a decrement in
performance in the bimodal condition compared to the
unilateral CI condition
1. Fitzpatrick, et al. (2009). Users experience of a cochlear implant combined with a hearing aid. Intl J Audioloogy, 48, 172-182.
Trends with Binaural Hearing Solutions
• Bimodal fitting
recommendations
are increasingly
becoming the
standard of care
• For a small
population, Bilateral
implantation may
be appropriate and
is a growing trend
1. Tyler, R, et al. (2002) Patients utilizing a hearing aid and a cochlear implant: Speech perception and localization. Ear Hear, 23:98-105.
2. Sucher, C., McDermott, H. (2009) Bimodal stimulation: Benefits for Music Perception and Sound Quality. Coch Impl Intl, 10 (Suppl.1): 96-99.
Adult Candidacy Considerations for CI’s
• To ensure maximal potential for
binaural processing, the most desirable
candidates have1:
– Post-lingual onset of hearing loss
– Relatively short duration of profound
hearing loss (e.g. less than 15 years),
– or consistent and continued use of
amplification in both ears up to
implantation
1. Cochlear White Paper, Rationale for Bilateral Cochlear Implantation in Children and Adults. by B. Robert Peters, 2006.
Bilateral Hearing with Cochlear Implants
• The potential benefits of bilateral hearing
with cochlear implants are much the same
as bilateral hearing with hearing aids.
• Benefits of bilateral cochlear implants may
include:
– Improved speech understanding in
noise
– Improved sound localization
– Improved patient- perceived
outcomes
– Patient never without sound
– Sound more balanced
– Hearing speakers from both sides
Demonstrated
in numerous
studies
Improved Speech Recognition with
1
Bilateral Cochlear Implants
• Study compared outcomes of 33 adults with
bilateral CIs with 40 adults with unilateral CI
• Improved speech recognition in quiet
– On average:
• Adults scored 19% higher on
sentences
• Adults scored 24% higher on words
– Than did unilateral cochlear implant
users
1. Dunn CC et al, (2008). Comparison of Speech Recognition and Location Performance in Bilateral and Unilateral Cochlear Implant Users
Matched on Duration of Deafness and Age at Implantation. Ear and Hearing. 29(3):352-359.
Improved Speech Understanding in Noise
with Bilateral Cochlear Implants
• Data showing improvement in speech
understanding in noise for some patients with
bilateral cochlear implants were reported in the
literature as early as 19881
• In research studies, improvement in speech
understanding in noise is largely due to the head
shadow effect, and to a lesser extent for some
patients, the binaural squelch effect and the
binaural redundancy effect2,3
• Improvements have been demonstrated in many
recent studies in both adults and children2-4
1. Balkany T, Boggess W, Dinner B (1988). Binaural cochlear implantation: comparison of 3M/House and Nucleus 22 devices with evidence of sensory integration.
Laryngoscope, Oct; 98(10): 1040-1043.
2. Litovsky, R et al. (2009) Spatial hearing and speech intelligibility in bilateral cochlear implant users. Ear and Hearing,30, 419-431.
3. Dunn, et al. (2010). Bilateral and Unilateral Cochlear Implant Users Compared on Speech Perception in Noise. Ear & Hearing, 31(2), 296-298.
4. Johnston JC, et al. (2009). Bilateral paediatric cochlear implants: a critical review. Int J Audiol. 48(9):601-17.
Improved Speech Understanding in Noise
1
with Bilateral Cochlear Implants
• 15 bilateral subjects evaluated after 3 & 6 months experience
• Speech recognition using BKB-SIN test
– Speech at 65 dB SPL from a loudspeaker at 0 degrees (frontal)
and noise from either 0 degrees or +/- 90 degrees (sides)
– SNR for 50% correct determined when listening with each
implant alone and while listening with both implants
• Findings:
– Significant benefit of listening with two ears in spatially separated
speech in noise (defined as >3.1 dB advantage in the bilateral
condition over unilateral conditions)
– Benefit was greater after 6 months listening experience than
after only 3 months listening experience
1. Litovsky, R et al. (2009). Spatial hearing and speech intelligibility in bilateral cochlear implant users. Ear and Hearing,30, 419-431.
Improved Sound Localization with
Bilateral Cochlear Implants
• Improved sound localization with bilateral cochlear
implants has been reported in the literature since the
1990s1
• Improvement in localization ability is due to integrating
independent information from each ear throughout the
auditory pathways
• This ability has been demonstrated in multiple recent
studies with cochlear implant recipientse.g.2,3
1. van Hoesel RJ, Clark, FM (1995). Fusion and lateralization study with two binaural cochlear implant patients. Ann Otol Rhinol Laryngol Suppl. Sep;166:233-5.
2. Dunn CC et al, Comparison of Speech Recognition and Localization Performance in Bilateral and Unilateral Cochlear Implant Users Matched on Duration of Deafness and Age
at Implantation. Ear and Hearing. 29(3):352-359, 2008.
3. Verschuur, CA, et al. (2005). Auditory Localization Abilities in Bilateral Cochlear Implant Recipients. Otology & Neurology, 26:965-971.
Improved Localization with Bilateral
1
Cochlear Implants
• Study compared outcomes of 33 adults with
bilateral CI with 40 adults with unilateral CI
• Findings:
– Enhanced sound localization
• Adults with bilateral cochlear
implants had significantly more
success identifying the location of
sounds
• Average localization precision was
25 degrees more accurate than
unilateral subjects
1. Dunn CC et al, Comparison of Speech Recognition and Location Performance in Bilateral and Unilateral Cochlear Implant Users Matched
on Duration of Deafness and Age at Implantation. Ear and Hearing. 29(3):352-359, 2008.
Improved Localization with Bilateral
1
Cochlear Implants
With a second CI,
precision in localizing
sound
more than doubles!
Mean angular error:
1. Verschuur, CA, et al. (2005). Auditory Localization Abilities in Bilateral Cochlear Implant Recipients. Otology & Neurology, 26:965-971.
Patient-Perceived Outcomes
• Favorable patient-perceived outcomes with bilateral
implants have been reported in the literature since
19921
• Improvements in self-perceived outcomes are likely
due to increased performance outcomes and
localization abilities
• Positive bilateral outcomes have been demonstrated
in multiple recent studies with cochlear implant
recipients2,3
• Patient-perceived outcome data are based on selfassessment metrics and as a result, results can be
variable
1. Green et al. (1992). Binaural cochlear implants. Am J Otol. 1992 Nov;13(6):502-6.
2. Litovsky et al. (2006). Simultaneous bilateral cochlear implantation in adults: A multicenter study. Ear & Hearing. 27(6): 714-731.
3. Noble et al. (2008). Hearing handicap ratings among different profiles of adult cochlear implant users. Ear & Hearing. 29(1): 112-120.
Patient-Perceived Outcomes
1
• Retrospective study using factor analysis from two
questionnaires
– Hearing Handicap Inventory for the Elderly
(HHIE)
– Hearing Handicap Questionnaire (HHQ)
• 35 bilateral recipients, 106 unilateral recipients, 42
with one cochlear implant and one hearing aid
• Findings:
– The least perceived handicap reported was by
the bilateral implant group
– Bilateral group also perceived significantly less
handicap than the other groups on the Social
Restriction subscores
1. Noble et al. (2008). Hearing handicap ratings among different profiles of adult cochlear implant users. Ear & Hearing. 29(1): 112-120.
Patient-Perceived Outcomes
• APHAB questionnaire data collected during a multi-center
study of 37 simultaneously implanted adult cochlear implant
users (using Nucleus 24)
• First administered after a 3 week period during which bilateral
CI recipients used only one implant (the better ear) then was
re-administered after a period of using the bilateral implants
again
• Findings:
– Subjects perceived their performance with the bilateral
implants as significantly better than with a unilateral implant
on the best-performing ear on all three communication
subscales of the APHAB
– No significant difference on the Aversiveness of Sounds
subscale
1. Litovsky et al. (2006). Simultaneous bilateral cochlear implantation in adults: A multicenter study. Ear & Hearing. 27(6): 714-731.
1
Clinical Management
Hearing Healthcare Team
Hearing Healthcare Team
Who’s on the Team?
Hearing Healthcare Team
Hearing Instrument Specialist
Who’s on the Team?
Hearing Healthcare Team
ENT Physician
Who’s on the Team?
Hearing Healthcare Team
Cochlear Implant Audiologist
Who’s on the Team?
Hearing Healthcare Team
Patient
Who’s on the Team?
Hearing Healthcare Team
ENT Physician
Hearing Instrument Specialist
Patient
Cochlear Implant Audiologist
Hearing Healthcare Team
A Happy Patient
Our Team
• Dr Mason and partner physicians
• In-office audiologists
• Baystate Medical Center Cochlear Implant
Program
• Community audiologists and hearing
instrument specialists
• Patients!
Clinical Management of the Bimodal Patient
• All hearing healthcare professionals should feel comfortable in
providing a bimodal hearing solution
– With changing trends, it is very likely that you will continue to
treat this patient population
• Know a brief history…
– When were they implanted
– What is their ability
– Overall satisfaction levels
• Remember the following…
– A unilateral cochlear implant patient has already met a best
aided binaural speech discrimination score of <60% prior to
cochlear implantation
– Patient must have a bilateral severe to profound sensorineural
hearing loss
6 Steps to a Bimodal Patient
Step 1: Create 3 HA Programs
Step 2: Match Loudness
Step 3: Determine Preferred HA Program
Step 4: Balance Loudness for CI + HA
Step 5: Fine Tune the HA for Bilateral Comfort
Step 6: Counsel on Continued HA Use
Step 1: Create 3 HA Programs
To start: Make sure the HA and CI are both ON
• Program 1: Prescription of Choice
• Program 2: Low Frequency Cut
-6 dB/octave below 2k Hz
• Program 3: Low Frequency Boost
+6 dB/octave below 2k Hz
Verify fit by using probe microphone.
Step 2: Match Loudness
To start: HA ON and CI OFF
• Balance HA programs 2 and 3 to program 1
• Adjust the HA gain of programs 2 and 3 until the
patient reports equal loudness when compared to
program 1
• This is a task for loudness only
Step 3: Preferred HA Program
To start: HA ON and CI OFF
• Have the patient listen to all 3 HA programs
• Which program provides the best sound quality
and/or speech understanding?
• This becomes the “preferred” program
Step 4: Balance Loudness
To start: HA and CI OFF
• Turn CI ON first, then turn HA ON
– things may sound a bit loud
• Point to the side where speech is loudest and adjust
HA gain accordingly
– If they point to CI, increase HA gain
– If they point to HA, decrease HA gain
• Aim for equal loudness between ears
Step 5: Fine Tune for Comfort
To start: Both HA and CI ON
• Present recorded speech at 50 dB SPL
– Adjust compression ratio/threshold to maintain
equal loudness between HA and CI
• Present recorded speech at 85 dB SPL
– Adjust MPO to not exceed loudness discomfort
levels
Step 6: Counsel on HA Use
• Counsel on the benefits of binaural hearing
• Set appropriate expectations of speech understanding
with the cochlear implant vs. the hearing aid
• Discuss binaural assistive listening devices (i.e., HATIS)
• Encourage a HA fine tuning appointment following
every cochlear implant mapping session
Summary
Key Messages
• TWO ears are better than ONE
• Bilateral hearing aids are the standard of care
• Bimodal hearing is an option for those who qualify
for cochlear implantation
• The potential benefits of hearing with bilateral
cochlear implants are much the same as hearing with
bilateral hearing aids.
Thank you!
Theodore Mason MD
Ear, Nose & Throat Surgeons of
Western New England
www.entassociates.org
www.cochlear.com
Download presentation slides at www/ihsinfo.org/convention
Questions?