Transcript BAHA 2010 ENT Residents

Bone Anchored
Hearing Aids
Dr. Amir Soltani
Clinical Audiologist
UBC Resident Otology Lecture Series
BC Children Hospital
Sep 13, 2013
BAHA
www.dramirsoltani.com/links/baha
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What is the BAHA system
A well recognized hearing treatment for
conductive and mixed hearing losses
since 1977 ,As well as SSD
 The BAHA system is composed of three
parts: a titanium implant, an external
abutment and a sound processor
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In the early 1960s it has discovered that
titanium provides an excellent material for
implantable devices. Titanium is accepted by the
human body and forms a bond with surrounding
bone.
 This is a process termed “osseointegration,”
which takes place as the titanium implant
integrates and forms a permanent structure with
the living bone. The process of bone
osseointegration is also the foundation for dental
implants..
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How does the BAHA system work for
Mixed and Conductive Hearing Loss?
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A sound processor picks up sound vibrations.
An abutment is attached to the sound processor and the implant.
The abutment transfers the sound vibrations from the processor to
the implant.
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Titanium implant is placed in the mastoid process, where it fuses
with the living bone (osseointegration). The implant transfers the
sound vibrations to the functioning cochlea.
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This creates direct (percutaneous) bone conduction. In contrast,
traditional BC hearing aids connect indirectly to the bone through
unbroken skin (transcutaneous) and work by exerting pressure
against the skull.
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Types of hearing loss
the BAHA system can help
 Mixed and Conductive hearing loss –
unilateral or bilateral fitting
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– Due to examples such as:
 Chronic otitis media
 Congenital atresia
 Cholesteatoma
 Middle ear dysfunction/disease
 External otitis
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The Baha Sound Processor snaps on to
the abutment. The processor is small,
discreet and is available in a variety of
colors. The volume controls are
conveniently located for easy adjustments.
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BAHA Candidate
Mixed and Conductive Hearing Loss
> 5 years of age
 < 45 dB HL BC PTA > or equal to 60%
speech discrimination scores
 Symmetric bone conduction thresholds are
defined as less than 10 dB difference in
average or less than 15 dB at individual
frequencies (0.5, 1, 2, and 4Khz)
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Bilateral Conductive Hearing Loss
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Biateral mixed hearing loss
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Severe Mixed or Sensorineural Hearing
Loss
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Unilateral Conductive Hearing Loss Canal
Atresea
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Audiological Assessments:
1: Pure tone Audiometry, including AC&BC
testing
 2: Speech tests through insert receiver or
headphones + Bone vibrator testing
 A: SRT B: SDS C: Quick SIN
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Impedance testing includling: (If possible)
Conventional (low probe tone) tympanometry
and high probe tone if necessary
 Acoustic reflex thresholds, Ipsi & Contra Lateral
stimuli
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OAE
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Test Rod
 The test rod is used as a pre-operative
device. It is particularly useful for potential
candidates who are on the limits of the
audiological criteria or if there is
uncertainty as to which side to place the
implant. The test rod can also be used to
demonstrate the abutment, snap coupling
and sound processor.
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Counseling
 1: Introduction ( How it works)
 2: Benefit – Limitation
 3: Documentation & Pre-post fitting
assessments Questionnaire (Cosi-Aphab)
 4: Realistic expectation
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Sound processors from Cochlear
 1: BAHA 3
 2: BP 100 & BP 110
 3: BAHA Intenseo
 4: BAHA Davino
 5: BAHA Compact
 6: Classic 300
 7: Cordell
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Oticon product
 1: Ponto
 2:Ponto pro
 **Programmable, under Noah, 4 memory,
10 band frequency shaping, adaptive multi
directional mic, data logging
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Direct bone conduction
Summary:
 Works independently of ear canal and
middle ear
 Direct transmission gives clear sound
 Preoperative testing possible
 High wearing comfort
 Safe and simple surgery
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Advantages of the BAHA system
in comparison to other alternatives
Mixed and Conductive Hearing Loss
Over bone conduction devices
 More comfortable
 Better sound quality
 Aesthetic appearance
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Over air conduction devices
No occlusion of the ear canal
 No feedback problems
 Sound bypasses the middle ear
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Over reconstructive surgery
Predictable results
 Low risk for the patient
 Reversible surgery
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Disadvantages of other devices
Mixed and Conductive Hearing Loss
Bone conduction devices
 Discomfort
 Poor sound quality
 Cumbersome
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Air conduction devices
Presence of ear mould aggravates
infection
 Acoustic feedback
 Dependent on middle ear function
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Reconstructive surgery
Potential risk of hearing damage
 Less predictable outcome
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FDA Clearances
1996 – 2002
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1996
– the BAHA system was cleared to treat mixed and conductive hearing
loss.
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1999
– the BAHA system was cleared for pediatric use in children age five and
older.
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2001
– the BAHA system was cleared for bilateral fittings.
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2002
– the BAHA system was cleared for use in patients with unilateral
sensorineural hearing loss also known as Single Sided Deafness (SSD).
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Clinical Aspects
Single Sided Deafness
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For adults:
– Difficulties to understand in group conversations, or
with noise.
– Difficulties to localize sounds,
– Difficulties to understand a person situated on the
deaf side.
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For children:
– - School handicap.
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Unilateral sensori-neural hearing loss
Single Sided Deafness
SSD
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Acoustic neuroma tumors
Sudden deafness
Neurological degenerative disease
Genetics
 Ototoxic treatments
 Inner ear malformation
 Trauma
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Options available
1: BAHA, Implanted in the mastoid of poorer
ear, transcranial routine of signal
2: Transcranial CROS, BTE or ITE power aid
fitted to the poorer ear
3: Trans Ear, Quasi BC fitted to the poorer ear
4: Wireless CROS(Phonak, Unitron)
5: Wired CROS
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BAHA Candidate
Single Sided Deafness
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> 5years of age
 Intended to improve speech recognition
 Intended for patients with SSD or unilateral sensorineural hearing loss when the other ear is normal
 Normal hearing is defined as PTA AC threshold equal to
or better than 20 dB at .5, 1, 2 and 3kHz
 For patients who cannot or will not use AC CROS HA
 Functions by transcranial routing of the signal
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How does the BAHA system
work for SSD?
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Advantages of the BAHA system
in comparison to other alternatives
Single Sided Deafness
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Effective approach in patients with unilateral deafness
Alleviates the degree of hearing handicap resulting from
the head shadow effect
Improves speech intelligibility in noise
Improves the patient’s quality of life
Provided a greater perceived benefit compared to CROS
system
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Head-shadow Effect
Review
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Minimal effect at 1500Hz, but continues upward to
approximately 15 dB at 5000 Hz (Staab 1988b)
 For speech the overall reduction of effective intensity is
approximately 6 dB (Tillman et.al., 1963)
 Its effect on speech intelligibility is approximately a
reduction of 23% when sound is coming directly from the
‘bad’ ear side.
 Binaural amplification in eliminating the head shadow
effect can be about 25% or 6 dB improvement in the S/N
ratio (from the Handbook of Clinical Audiology, Katz)
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 Conclusion
Why BAHA for Single Sided Deafness
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Effective approach in patients with unilateral
deafness
Alleviates the degree of hearing handicap
resulting from the head shadow effect
Improves speech intelligibility in noise
Improves the patient’s quality of life
Provided a greater perceived benefit compared
to CROS system