Baha Candidate Selection Guide (2.3 MB) - Cochlear

Candidate Selection Guide

Products in this manual are protected by the following patents: US 5 735 790, US 5 7 935 170, EP 0715839, EP 0715838 and
corresponding patents in other countries and pending patent applications. All products can be subject to change without notice.
No part of this publication may be replaced, stored in a retrieval system, or transmitted in any form, by electronic, mechanical,
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Caution: Federal law (USA) restricts this device to sale by or on the order of a medical practitioner.
© Cochlear 2009
Cover image: Baha Intenso, table of contents image: Test rods

Contents
4 Introduction
6 PART 1: Identifying candidates
11 PART 2: Candidate evaluation
14 PART 3: Counselling
17 PART 4: Paediatric candidacy
20 Appendix 1: Device considerations
23 Appendix 2: Case histories
28 Appendix 3: Clinical results
29 References

Introduction
4

Introduction
This Candidate Selection Guide provides detailed
information on how to select candidates who will benefit
from Baha ® . With bone conduction, sound bypasses the
outer and middle ear, and goes directly to the inner ear. Baha
is an effective implantable hearing solution for people with
conductive hearing loss, mixed hearing loss, or single-sided
sensorineural deafness (SSD). The Baha system works by
enhancing natural bone conducted sound.
The advantages of Baha
The main advantage of Baha is that it bypasses the conductive element of a hearing loss through
direct bone conduction and only needs to compensate for the sensorineural element.
Therefore, for conductive or mixed hearing loss with an air-bone gap >30 dB, measured at
500, 1000, 2000, and 4000 Hz (PTA 4 ), Baha should be the amplification method of choice. 1–6
When worn on the deaf side, the Baha device transfers sound directly to the healthy cochlea,
which eliminates head shadow effect, enables 360˚ sound awareness, and improves speech
understanding in noise. 7,8,9
There are also several medical indications where Baha could be the best solution for the
candidate. Read more about this on page 11.
Getting Baha for your candidate
When you have identified a candidate for Baha, the candidate will need to be referred
to an ENT surgeon for consultation. Candidates considered suitable for surgery will then
have a small titanium implant placed in the mastoid bone behind their ear.
The Baha system consists of a high-performance sound processor, an abutment and a titanium
implant which is located in the bone behind your ear. The surgical procedure may be performed
under a local anaesthetic and is generally regarded as minor surgery from both the surgeon’s
and candidate’s point of view. The Baha sound processor is easily connected and disconnected
once the implant has fused with the bone (a process known as osseointegration).
Advantages of Baha
Compared to conventional
air conduction (AC) hearing aids:
• Less need for amplification
- because the conductive element
of the hearing loss is bypassed
• No occlusion of the ear canal. 10,11
Compared to middle ear surgery:
• Safe and reliable means
of restoring hearing
• A reversible intervention
• No risk of additional
hearing impairment
• The Baha sound processor can
be evaluated prior to surgery.
Introduction
5

PART 1: Identifying candidates
6
PART 1: Identifying candidates
There are three main audiological indications for Baha ® :
• Conductive hearing loss
• Mixed hearing loss
• Single-sided sensorineural deafness (SSD)
For each type of hearing loss there are specific criteria that will indicate who is
a Baha candidate. There are also a range of other medical indications that may
identify an individual as a Baha candidate. For details please see page 11.

Conductive hearing loss
Most candidates with a conductive hearing loss will benefit from Baha. As Baha sends
sound directly to the cochlea via bone conduction, the conductive element of the hearing
loss is effectively bypassed. This means that very little amplification is required.
Criteria:
Size of conductive hearing loss
Studies suggest that candidates with an air-bone gap of more than 30 dB (PTA 4 )
will experience significant advantages with Baha compared to an air conduction
(AC) hearing aid. 1-6
Hearing Level (dB HL)
-10
0
10
20
30
40
50
60
70
80
90
100
110
120
125
Conductive hearing loss
Frequency (Hz)
250 500 1K 2K 4K 8K
750 1.5K 3K 6K
PART 1: Identifying candidates
Possible causes of conductive loss:
• Cholesteatoma
• Chronic otitis media
• Congenital aural atresia
• External otitis
• Genetic causes
• Ossicular disease
• Other middle ear dysfunctions/diseases
• Otosclerosis
7

PART 1: Identifying candidates
8
Possible causes of mixed loss:
Mixed loss refers to a hearing loss that
has both conductive and sensorineural
elements. The sensorineural element
of a hearing loss can stem from:
• Disease related factors
• Genetic causes
• Noise trauma
• Otoxicity
• Presbycusis
• Cochlear otosclerosis
For additional etiologies, see also
Possible causes of conductive loss,
page 8 and Medical indications, page 11.
Mixed hearing loss
Many individuals with mixed hearing loss are suitable candidates. Baha sends
sound directly to the cochlea via bone conduction, bypassing the conductive
element of the hearing loss and providing amplification to compensate for
the sensorineural element.
Criteria:
The air-bone gap
The air-bone gap is a good indicator of how suitable Baha will be for a
candidate. The greater the air-bone gap, the more the candidate will benefit
from Baha. Studies suggest that candidates with an air-bone gap of more than
30 dB (PTA 4 ) will benefit more from Baha than from a hearing aid. 1-6
Extent of the sensorineural hearing loss
Clients with a mild-to-moderate sensorineural component to their hearing loss are
suitable candidates. The Baha sound processor can compensate for some degree
of the sensorineural loss but, as the conductive part of the loss is bypassed, little
amplification is required. Compared to conventional hearing aids, the Baha uses
much less amplification.The most powerful Baha sound processor makes it possible
to compensate for a sensorineural element of up to 65 dB in a mixed hearing loss.
For more information, please see the section on Device selection, page 21.
Hearing Level (dB HL)
-10
0
10
20
30
40
50
60
70
80
90
100
110
120
125
Mixed hearing loss
Frequency (Hz)
250 500 1K 2K 4K 8K
750 1.5K 3K 6K

Single-sided deafness (SSD)
The Baha system is indicated for candidates with SSD and normal hearing in the good ear.
The Baha sound processor picks up sound on the deaf side and sends it via bone conduction
to the contralateral intact cochlea to overcome the head shadow effect, which leads to
improved speech understanding and 360º sound awareness. 7,8,9,12
Criteria:
Level of hearing loss in the good ear
Candidates with normal hearing or mild hearing loss in the good ear will benefit from
Baha. 13 In cases with a more pronounced hearing loss in the good ear, Baha may not be
the best solution.
Candidate motivation
As SSD clients may have specific expectations due to their type of hearing loss, it is
important that their expectations are realistic and that they perceive hearing from the
deaf side as a need.
Hearing Level (dB HL)
-10
0
10
20
30
40
50
60
70
80
90
100
110
120
125
Single-sided deafness (SSD)
Frequency (Hz)
250 500 1K 2K 4K 8K
750 1.5K 3K 6K
Possible causes of
single-sided deafness:
• Acoustic neuroma tumours
• Genetic causes
• Ménière’s disease
• Neurological degenerative disease
• Ototoxic drugs
• Sudden deafness
• Surgical interventions
• Trauma
Advantages of Baha
PART 1: Identifying candidates
Compared to CROS aid:
• No occlusion of the hearing ear
• No need of cables to transmit
sound from the deaf side.
• Better sound quality
9

PART 1: Identifying candidates
10
Advantages of Baha
Compared to conventional
bone conduction hearing aids:
• Direct bone conduction
• Better amplification – no weakening
of the signal as it passes through skin
• Superior sound quality
• Improved comfort – no constant
pressure to the skull
• No occlusion of the ear canal
• Discretion and improved
cosmetic appearance14,16,17, Compared to middle ear surgery:
• Safe and reliable means
of restoring hearing
• A reversible intervention
• No risk of additional
hearing impairment
• Results can be evaluated
prior to surgery.
Medical indications
Besides the type and degree of hearing loss, there are several medical indications
that identify an individual as a candidate for Baha. These indications are:
Allergies
Client allergies may be aggravated by the placement of an ear mould. A Baha device
maintains an open ear canal.
Radical cavity
Individuals treated for chronic mastoiditis with a radical cavity may be precluded
from the use of a conventional AC aid because such aids may occlude the ear canal
thus aggravating the condition. The Baha system allows the ear canal to be left open.
Congenital malformations
For most candidates with congenital ear malformation, surgical intervention or
a conventional bone-conduction hearing aid is often prescribed because an AC
hearing aid is simply not an option. Baha has several advantages over conventional
BC hearing aids and, compared to surgical reconstruction, the Baha system provides
a reliable and cost efficient solution. 14,15 In cases where an auricular prosthesis or
surgical reconstruction is planned, the position of the Baha implant in relation to
these procedures should be considered.
Draining ears
One common problem for otologists when treating candidates with middle ear
disease is getting a dry ear with good hearing. If the candidate uses an AC hearing
aid, the ear mould in the ear canal will aggravate the condition. When using the
Baha system, the ear canal is left open, thus allowing the ear to dry. 1
Ear canal stenosis
Individuals with stenosis of the ear canal are not suitable for surgical intervention,
and the use of conventional hearing aids can be difficult when fitting an ear mould.
With Baha, the ear canal is bypassed using Direct Bone Conduction.
Previous ear surgery
Candidates who have had previous surgeries using, for example, a canal wall down
technique, may find it difficult to wear an ear mold without feedback problems.
As no ear mould is required, Baha is a good solution.
Syndromic hearing losses
Individuals with syndromes such as Downs, 34 Goldenhar 16 and Treacher Collins
can be suitable candidates for Baha. Treatment of these individuals often requires
special consideration and counselling. A personal counselling plan that considers
the type of syndrome, the severity of the condition, and general abilities is
suggested. For these candidates, parents or caregivers will often take an active
role in the care of the sound processor, abutment and abutment area, and they
will need special instructions early on in the candidate selection process. .1

PART 2: Candidate evaluation
In addition to the audiological evaluations, the candidate should have the opportunity to
listen to a Baha ® sound processor. Several Baha products can be used for this purpose: test rod,
testband, headband, and Baha ® Softband. The main difference between these products is that
the testband and test rod are for short-term testing, while the headband and Baha Softband
are for longer trials.
*Depending on the client and the frequency, sound is weakened by 2–15 dB as it passes through skin.
PART 2: Candidate evaluation
11

PART 2: Candidate evaluation
12
Suggested audiological tests:
• Pure tone audiometry (average
bone thresholds at 500, 1000, 2000,
and 3000 Hz) 33
• Speech audiometry /HINT/QuikSin
testing (for instance maximum speech
intelligibility using phonetically balanced
(PB) word lists)
• Sound field testing (Baha device
on a testband or test rod, or a Baha
Softband)
Practical points to consider:
• Manual dexterity
• Cosmetic aspects
• Driving (if the candidate is a taxi
driver, then the side facing the
passenger is a good alternative)
• Telephone use (if the candidate
uses the telephone frequently, the
opposite side to the “writing hand”
may be the best choice)
Adult candidates
The Baha system works independently of the severity of the conductive part of the hearing
loss because sound bypasses the outer and middle ear. The bone conduction threshold is
therefore the most relevant measurement in the audiological assessment. Use the candidate’s
air-bone gap as a guide to the benefits that can be expected from choosing Baha instead
of an AC hearing aid. Comparing the results of functional gain measurements in sound field,
with and without the sound processor, will also be useful.
Sound field testing of a Baha sound processor allows the candidate to hear the sound
of a Baha device before surgery. For a realistic experience, allow the candidate to test a
sound processor in different sound environments (for example by taking a walk around
the hospital/clinic or surrounding area). For candidates with SSD, a longer trial, which allows
testing of a Baha sound processor at home or work, is crucial.
Note: In candidates with bone defects or other problems where the testband/
headband is not suitable, the Baha Softband may provide a better testing solution
(see Listening with a Baha Softband, page 27).
Selection of implant side
Bilateral fitting
For candidates with binaural hearing loss, a bilateral fitting of Baha, which may lead to binaural
hearing, should be considered as this improves speech understanding, sound localisation, and
general candidate satisfaction. 17-19 However, for true directionality, bone conduction thresholds
should be symmetrical (defined as less than 10 dB difference on average (PTA 4 ) or less than
15 dB at individual frequencies).
Unilateral fitting
For SSD, implantation is made on the deaf side. For conductive or mixed losses the general
recommendation is to choose the side with the best cochlear function (the best bone
conduction thresholds). The side the candidate percieve as having the greatest handicap
should, however, be taken into account.

Listening with a Baha testband
1. Attach the sound processor to the plastic snap connector disc on the testband.
2. Test that the Baha sound processor works by putting on the testband, plugging
your ears and introducing sound.
3. Put the testband on the candidate’s head placing the plastic snap connector
disc against the selected mastoid.
4. Position the sound processor behind the ear. To avoid feedback, make sure
the processor doesn’t touch the ear or skin
Note: The testband is only intended for short term testing. If used for
a longer periods, there is a risk for skin irritation or headaches..
Sound processor considerations
Due to weakening of the sound signal as it passes through skin (attenuation), the gain from
a Baha device is reduced by 2-15 dB* during sound-field testing compared to
a sound processor fitted to an osseointegrated implant. 18,19 Therefore, we recommend
using a stronger processor for the test than the candidate’s audiogram would indicate.
A stronger processor is most noticeable at higher frequencies because higher frequencies
are weakened to a greater extent than low frequency signals. 20 For SSD, use a head worn
sound processor. A body worn device will not help alleviate the head shadow effect due to
its microphone placement.
1
2
3
4
PART 2: Candidate evaluation
13

PART 3: Counselling
14
PART 3: Counselling
Before they are treated, candidates should be motivated, well informed and counselled
to have realistic expectations. Baha ® counselling tools will be helpful for these purposes.
The main points that should be covered during counselling are:
• Benefits of Baha to the client
• The process of getting Baha
• Expectations
• Aftercare
• Reimbursement/funding

Benefits of Baha ® for the client
Conductive/mixed hearing loss
The use of direct bone conduction to transmit sound gives Baha several unique advantages
over other treatments for conductive/mixed hearing loss.
The most notable benefits of Baha for a candidate with conductive or mixed hearing loss,
compared to conventional hearing aids, are:
• Need for less amplification as the conductive element of the hearing loss is bypassed
• No occlusion of the ear canal
• Excellent sound quality as very little amplification is required
When compared to middle ear surgery Baha will provide:
• A safe and reliable way to restore the candidate’s hearing
• No risk of additional hearing impairment
• A reversible intervention
• The possibility to test the Baha before surgery is performed
In comparison to conventional bone conduction hearing aids Baha will give the candidate:
• Better sound quality due to direct bone conduction.
• Increased wearing comfort, as there is no constant pressure to the skull
If the candidate has frequent ear infections Baha can provide:
• Reduced incidence
• A dryer ear canal as the ear canal is left open
SSD
As SSD candidates may have specific expectations due to their type of hearing loss,
it is important to ensure that these expectations are realistic. The audiologist or physician
can help the client to understand their percieved handicap, and more importantly,
their motivation for hearing.
Note: Restoration of directional hearing should not be expected after fitting as
all sounds will be processed by the remaining functioning cochlea. 8 Some clients,
however, report a form of directional hearing, but this is a result of the increased
spacial awareness rather than true sound localisation.
For candidates with SSD, Baha provides several benefits when compared to
a conventional CROS aid:
• No occlusion of the hearing ear
• No need of cables to transmit sound from the deaf side
• Better sound quality
• Only one device is worn, versus two with the CROS aid
PART 3: Counselling
15

PART 3: Counselling
16
The process of getting Baha
Review the process of Baha treatment with the candidate:
• Inform the candidate about the different audiological evaluations that will be performed.
• Tell the candidate that they will need to have surgery. Emphasise that the surgical
procedure is considered minor and may be performed in an outpatient setting under
local or general anaesthetic.
• Explain that a small titanium implant will be placed just behind the chosen ear.
Clarify that the implant will be connected to an abutment and that it is the abutment
that will protrude through the skin. At this point showing an actual implant and abutment
may reduce the candidate’s anxiety.
• Tell the candidate that after surgery they will have a small hair-free area around the
abutment and that they may experience some numbness in that area. The numbness
may or may not pass with time.
• Inform the candidate that they will have a dressing and pressure bandage over
the abutment when they come from surgery and that the dressing will be changed
(5–7 days post-operatively) and removed (10–14 days post-operatively).
• Explain how long the implant will take to fully osseointegrate (usually up to 3 months)
and how the sound processor will be fitted.
Note: Emphasise that there is no risk of further damage to the candidate’s
hearing from Baha surgery. More detailed information on the surgical procedure
should be provided by the surgeon.
Expectations
Ensure the candidate has realistic expectations. Preoperative testing is essential for keeping
candidate expectations reasonable. Listening to a Baha sound processor on a testband/Baha
Softband provides a practical experience close to that of the post-surgical outcome. In this
context, it is important to note that true directionality will not be restored for SSD candidates.
Aftercare
Candidates must be able to maintain and clean the area around the abutment (either
themselves or with help from others). Careful consideration must be given to the candidate’s
ability to maintain proper hygiene. With children, responsibility for maintaining hygiene falls
on the parents or caregivers.
Reimbursement and funding
As reimbursement for Baha is an important factor for the candidate, this should be discussed
during the preoperative evaluation. Terms and conditions of reimbursement and funding for
Baha differ from area to area. For information about the terms and conditions applicable in
your area, please consult your local Cochlear representative. In the U.S.A., please refer to
the Baha reimbursement guide.
Warranty
The warranty does not cover defects or damage arising from, associated with, or related to
the use of a Cochlear implant/abutment with any non-Cochlear sound processor or the use
of non-Cochlear implant/abutment with a Cochlear sound procesor. Refer to the Cochlear
Baha Global Limited Warranty card for details.

PART 4: Paediatric candidacy
Client selection
The Baha ® sound processor can be fitted to infants and children in need of amplification
via bone conduction. The indications for a Baha device are generally the same as for adults.
PART 4: Paediatric candidacy
17

PART 4: Paediatric candidacy
18
Use age appropriate tests to
evaluate audibility and speech
understanding:
• Auditory Brainstem Response
(ABR): Infants
• Auditory Steady State Response
(ASSR): Infants
• Otoacoustic Emission (OAE): Infants
(requires normal middle ear function)
• Behavioural Observational
Audiometry (BOA): Infants from
7–8 months
• Visual Reinforcement Audiometry
(VRA): Children from about six
months up to 2–3 years
• Play audiometry: Children between
3–5 years of age *
• Listening with a Baha Softband
* Play audiometry can be made with
warble tones, speech or animal sounds.
Evaluation
As in adult patient evaluation, the bone conduction threshold is the most relevant in
the audiological assessment. Use the air-bone gap as a guide to the benefits that can be
expected from choosing Baha. There may also be medical indications why Baha will be
the solution of choice for the child. If possible, compare the results of the functional gain
measurements in the sound field booth with and without the sound processor.
We recommend fitting infants and children who are not ready for implantation with the
Baha Softband. This will instantly improve the child’s hearing and is a very good introduction
to the advantages of Baha, both for the child and for the parents/caregivers. The decision to
implant the child can then be postponed to a later date and is usually easy, once the benefits
to the child have been observed.
Selection of implant side
Clinical research suggests that children with binaural conductive hearing loss should be
fitted with bilateral Baha sound processors on a Baha Softband preferably before the age
of 6 months. 1 If bilateral fitting is contraindicated, fit the side with the best bone conduction
thresholds and skull thickness. For children with SSD, the Baha Sound Processor is placed on
the deaf side.
Counselling
Parents of hearing-impaired children will have a greater need for counselling. Parents may
have questions about the hearing loss and how it will affect their child’s development. They
need information on how to help their child achieve the best possible results, especially in
speech and language development. They will want to know why Baha is the best solution
for their child. In addition, counselling should cover the Baha treatment process from both
a short- and long-term perspective. Therefore, both Baha Softband and surgery should
be discussed.
Device selection
The Baha Softband is a preoperative hearing solution and does not provide the full benefits
of a sound processor connected to an implant (see page 13). This must be taken into
consideration when choosing an appropriate sound processor.

Listening with a Baha ® Softband
Try to make the first moments with the Baha Softband as pleasant for the child as possible.
It is very important that the child has positive associations with using the Baha Softband.
1. Attach the sound processor to the plastic snap connector disc on the Baha Softband.
2. Test that the Baha Softband works by putting it on yourself, plugging your ears and
introducing sound.
3. Put the Baha Softband around the child’s head, quite loosely at first.
4. Place the plastic snap connector disc against the mastoid or another bony location
of the skull. Avoid placing it on the temple bone, as this may be uncomfortable.
Check that the entire snap connector disc is in contact with the skull bone. Turn the
volume up slowly.
5. Tighten the Baha Softband until it is close-fitting enough to ensure effective sound
transmission but loose enough not to cause the child any discomfort.
6. Have the parent or caregiver talk to the child, sing a song, or another pleasant
sounding experience. Watch for the child’s reaction.
Tip: Make sure your finger fits between the skull and Baha Softband – this will ensure
that the Baha Softband is not too tight.
Note: Once the Baha Softband is tight enough to transmit sound
effectively, additional tightening will only increase the sound marginally. 3
Caution:These products contain natural rubber latex that may
cause allergic reactions.
Additional considerations
Early amplification
Early access to amplification is crucial for a child’s speech, language and educational
development. Yoshinaga-Itano reports that children who receive hearing rehabilitation
before the age of 6 months perform significantly better on language tests at the age of
3 to 4 years than do children fitted later in life. 26 The Yoshinaga-Itano study concludes
that a delay in intervention may lead to a permanent language deficit.
Recommended age for implantation
Implant placement must wait until the child has sufficient bone volume and bone quality.
This can vary from child to child but, based on studies, the child should be more than
2 years old and have a skull bone at least 2.5 mm thick. 27,28,29 The Baha ® Softband can be
used on infants from the age of 6 weeks. In the U.S.A., the FDA approves Baha
implantation of children aged 5 years and older.
Warning! A Baha sound processor contains small parts. Constant adult
supervision is required for Baha users under 3 years of age.
1
2
3
4
PART 4: Paediatric candidacy
19

Appendix 1: Device consideration
20
Appendix 1: Device consideration
When calculating the amplification needs of a Baha ® candidate, the bone conduction thresholds
in the audiogram provide the most important information. The Baha sound processor will have
to produce sufficient power to compensate for any sensorineural element to the hearing loss.
To help your candidate select the correct sound processor, follow these guidelines.

Device selection based on hearing loss type
Conductive hearing loss
For candidates with a purely conductive loss we recommend focusing on which sound
processor has the most useful features for the candidate. Any Baha device will provide
sufficient amplification.
Mixed hearing loss
The fitting range of the selected sound processor must cover the size of the sensorineural
loss as the device will need to compensate for the degree of sensorineural impairment.
Similar to other hearing devices, the clinical rule of thumb is: if the hearing loss is in the lower
third of the fitting range, a more powerful sound processor may result in better outcomes
for the candidate. Providing a second device for situations where more power is required
could also be considered.
SSD
For most candidates with SSD, the choice of sound processor can be based on which device
has the most useful features. In some cases, however, the sound processor may need to
deliver added amplification to provide sufficient audibility in the contralateral ear.
SSD candidates may benefit from a more powerful head worn Baha in the following situations:
• Larger than expected interaural attenuation. Extra amplification will be required to ensure
audibility in the good ear.
• Sensorineural hearing loss developing in the ‘good’ ear over time due to presbycusis
or noise exposure. Extra gain will be required to amplify the sound above the candidate’s
thresholds.
To evaluate the benefit of Baha for SSD candidates, a longer trial or testing – not sound field
testing – that only happens in a sound booth is crucial. Usually a two-week trial will provide
a good indication of what the candidates may expect from Baha.
Note: Due to weakening of the sound signal as it passes through the skin, the gain from
a Baha sound processor will be reduced by 2-15 dB during sound field testing. Therefore,
we recommend using the most powerful head worn device for this process.
Appendix 1: Device consideration
21

Appendix 1: Device consideration
22
Additional considerations for device selection
• Improved clarity of speech in difficult listening situations
A sound processor with a directional microphone will prioritise sounds coming from the
front to sounds coming from behind, which makes it easier to hear speech in noise.
• Better comfort in noisy listening situations
The directional microphone provides less gain for lower pitched sounds making it easier to
hear in noisy situations. In addition, a directional microphone prioritises sounds from the
front to those from behind, which improves speech understanding in noise.
• Improved audibility in difficult listening situations
There may be situations where additional audibility is needed. A more powerful Baha
device will make sounds (especially those in the higher frequencies, e.g., ‘s’ and ‘sh’) easier
to understand. A Baha with a specific noise program will ensure audibility and comfort.
• Listening from a distance
A more powerful sound processor will amplify soft sounds so they become more audible.
This will enable hearing from a distance (e.g., in church).
• Music Appreciation
A sound processor that does not use Active Feedback Cancellation will process the music
cleanly without mistaking music for feedback.
• Cosmetic appearance
The smaller Baha devices are less noticeable.
Benefits of providing an
additional sound processor
Each device provides different performance advantages, depending on the specific listening
environment. Therefore, some candidates may benefit from having two different sound
processors. This gives the candidate the unique opportunity of selecting the best sound
processor for a given situation.

Appendix 2: Case histories
Hearing Level (dB HL)
Patient: Male
Age: 36
Occupation: Salesman
Type of hearing loss: Unilateral mixed hearing loss
Diagnosis: Congenital facial paraesthesia and
malformation of outer and middle ear
Aided side: Left
Hearing Level (dB HL)
-10
0
10
20
30
40
50
60
70
80
90
100
110
120
125
Unaided audiogram:
Frequency(Hz)
Frequency (Hz)
250 500 1K 2K 4K 8K 125
750 1.5K 3K 6K
-10
0
10
20
30
40
50
60
70
80
90
100
110
120
History: The client received a Vistafix ® ear prosthesis in his
late teens and was later fitted with a Baha device in 2006.
He had never used a hearing aid before. The benefits of Baha
have been many and the client considers it a useful solution
to his hearing loss.
PTA 4 improvement: 64 to 26 dB
Hearing Level (dB HL)
Aided audiogram:
Frequency (Hz)
250 500 1K 2K 4K 8K
750 1.5K 3K 6K
B = Aided threshold with Baha in soundfield testing
Appendix 2: Case histories
23

Appendix 2: Case histories
24
Patient: Female
Age: 46
Occupation: Homemaker
Type of hearing loss: Bilateral conductive hearing loss
Diagnosis: Treacher Collins syndrome
Aided side: Right
Hearing Level (dB HL)
-10
0
10
20
30
40
50
60
70
80
90
100
110
120
125
Unaided audiogram:
Frequency (Hz)
250 500 1K 2K 4K 8K 125
750 1.5K 3K 6K
-10
0
10
20
30
40
50
60
70
80
90
100
110
120
History: The client received her first Baha 27 years
ago and still uses the same implant. She changed the
abutment to the snap coupling when she upgraded
her Baha ® sound processor.
PTA 4 improvement 71 to 21 dB
Hearing Level (dB HL)
Aided audiogram:
Frequency (Hz)
250 500 1K 2K 4K 8K
750 1.5K 3K 6K
B = Aided threshold with Baha in soundfield testing

Patient: Female
Age: 13
Occupation: Student
Type of hearing loss: Bilateral Conductive hearing loss
Diagnosis: Treacher Collins syndrome
Aided side: Left
Hearing Level (dB HL)
-10
0
10
20
30
40
50
60
70
80
90
100
110
120
125
Unaided audiogram:
Frequency (Hz)
250 500 1K 2K 4K 8K
750 1.5K 3K 6K
History: The client has used Baha since she was 3 years old.
She experiences great benefit from the Baha in classroom
situations.
PTA 4 improvement: 54 to 20 dB
Hearing Level (dB HL)
-10
0
10
20
30
40
50
60
70
80
90
100
110
120
125
Aided audiogram:
Frequency (Hz)
250 500 1K 2K 4K 8K
750 1.5K 3K 6K
B = Aided threshold with Baha in soundfield testing
Appendix 2: Case histories
25

Appendix 2: Case histories
26
Patient: Male
Age: 53
Type of hearing loss: Bilateral mixed hearing loss
Occupation: Nurse
Diagnosis: Chronic otitis media, middle ear bones
removed after osteomyelitis, tympanic membranes
ruptured bilaterally
Aided side: Right
Hearing Level (dB HL)
-10
0
10
20
30
40
50
60
70
80
90
100
110
120
125
Unaided audiogram: Aided audiogram:
Frequency (Hz)
250 500 1K 2K 4K 8K 125
750 1.5K 3K 6K
-10
0
10
20
30
40
50
60
70
80
90
100
110
120
History: The client has had hearing problems his entire life.
The client received his Baha in 2004. In 2007 he received a
new implant after losing the original due to trauma. He uses
his Baha constantly and is extremely pleased with the sound.
PTA 4 improvement: 85 to 24 dB
Hearing Level (dB HL)
Frequency (Hz)
250 500 1K 2K 4K 8K
750 1.5K 3K 6K
B = Aided threshold with Baha in soundfield testing

Patient: Male
Age: 52
Type of hearing loss: Single-sided deafness (SSD)
Occupation: Nurse
Diagnosis: Acoustic Neuroma (AN) left ear
AN surgery took place in 1998
Aided side: Left
Hearing Level (dB HL)
-10
0
10
20
30
40
50
60
70
80
90
100
110
120
125
Unaided audiogram:
Frequency (Hz)
250 500 1K 2K 4K 8K
750 1.5K 3K 6K
Hearing Level (dB HL)
History: The client was offered a CROS aid following
acoustic neuroma surgery. He used the CROS aid for one
month but felt more handicapped with it, than without it.
An implant for the Baha system was placed in May 2001, and
in August of that year, a Baha was fitted. At clinical follow-up
one year later he reported using the Baha sound processor
for 14 hours a day, seven days a week.
Hearing Level (dB HL)
-10
0
10
20
30
40
50
60
70
80
90
100
110
120
125
Aided
Frequency(Hz)
audiogram:
Frequency (Hz)
250 500 1K 2K 4K 8K
750 1.5K 3K 6K
B = Aided threshold with Baha in soundfield testing
Appendix 2: Case histories
27

Appendix 3: Clinical results
28
Appendix 3: Clinical results
The Baha system has proven to be an effective hearing solution and several clinical studies demonstrate client benefits.
Mixed/conductive hearing loss
“The Baha provides a reliable and predictable adjunct for auditory rehabilitation in appropriately selected clients,
offering a means of dramatically improving hearing thresholds in clients with conductive or mixed hearing loss
who are otherwise unable to benefit from traditional hearing aids.“ 6
“It can be stated that clients with an acquired unilateral air-bone gap benefited from using the Baha. This was not only
reflected in the audiological results, but also in the clients’ opinions.” 30
SSD
“Subjects found Baha amplification to be consistently more useful in a variety of listening environments experienced in daily life.
On HINT testing the Baha provided clinically significant benefit in several noise conditions.” 31
“The speech-in-noise measurements demonstrated the efficacy of the Baha [...] to lift the head shadow.
Clients were still satisfied at 1-year follow-up, according to the four questionnaires*.” 8
Paediatric
“Bone-anchored hearing aids provide an exceptionally effective method of rehabilitating the child with conductive hearing loss
or inability to wear AC aids due to chronic otorrhea.” 29
“The Baha is an effective hearing aid for children with congenital hearing loss, whether they were previous air-conduction
or bone-conduction aid wearers. The majority was overall more satisfied with their Baha than their previous aid.” 32
“Fixture survival rates equivalent to those seen in an adult population. Also significant improvements seen in aided thresholds
with Bahas demonstrate the safety and efficacy of the Baha.” 12
*The Abbreviated Profile of Hearing Aid Benefit, the Glasgow Hearing Aid Benefit Profile, the International Outcome
Inventory for Hearing Aids, and the Single-Sided Deafness questionnaire.

References
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Tjellström A. Consensus statements on the Baha system: where do we stand at present? The Annals of otology, rhinology &
laryngology 2005 Dec;114(195):2-12.
2. Hol MK, Snik AF, Mylanus EA, Cremers CW. Long-term results of bone-anchored hearing aid recipients who had previously
used air-conduction hearing aids. Archives of Otolaryngology-Head and Neck Surgery 2005 Apr;131(4):321-5.
3. McDermott AL, Dutt SN, Reid AP, Proops DW. An intraindividual comparison of the previous conventional hearing aid with
the bone-anchored hearing aid: The Nijmegen group questionnaire. The Journal of Laryngology and Otology 2002 Jun;116 Suppl
28:15-9.
4. Mylanus EA, Snik AF, Cremers C. Patients’ opinion of bone-anchored vs. conventional hearing aids. Archives of Otolaryngology-
Head & Neck Surgery.1995 Apr;121(4):421-5.
5. Mylanus EA, van der Pouw KC, Snik AF, Cremers CW. Intraindividual comparison of the bone-anchored hearing aid and airconduction
hearing aids. Archives of Otolaryngology-Head & Neck Surgery 1998;124(3):271-6.
6. Lustig LR, Arts HA, Brackmann DE, et al. Hearing rehabilitation using the Baha bone-anchored hearing aid: results in 40 clients.
Otology & Neurotology 2001;22(3):328-34.
7. Wazen JJ, Spitzer JB, Ghossaini SN, Fayad JN, Niparko JK, Cox K, et al. Transcranial contralateral cochlear stimulation in unilateral
deafness. Otolaryngology-Head & Neck Surgery 2003;129(3):248-54.
8. Hol MK, Bosman AJ, Snik AF, Mylanus EA, Cremers CW. Bone-anchored hearing aids in unilateral inner ear deafness: an
evaluation of audiometric and client outcome measurements. Otology & Neurotology 2005 Sep;26(5):999-1006.
9. Bosman AJ, Hol MKS,Snik AFM,.Mylanus EAM Cremers CWRJ, Bone-anchored hearing aids in unilateral inner ear deafness.
Acta Oto-Laryngologica 2003;123(2):258-260.
10. Burell SP, Cooper HC, Proops DW. The bone-anchored hearing aid-the third option for otosclerosis. Journal of Laryngology
and Otology 1996 Dec;110 Suppl 21:31-37.
11. Snik AFM, Mylanus EAM, Creemers WRJ. The Bone-anchored hearing aid – A solution for previously unresolved otologic
problems. The Otolaryngologic Clinics of North America 2001;34(2):365-72.
References
12. Tietzle L, Papsin B. Utilization of bone-anchored hearing aids in children. International Journal of Pediatric Otorhinolaryngology
2001 Apr;58(1):75-80.
13. Lin LM, Bowditch s, Anderson MJ, May B, Cox K, Niparko JK. Amplification in the rehabilitation of unilateral deafness: speech in
noise and directional hearing effects with bone-anchored hearing aids Baha Compact and Divino. Otology and Neurotology 2006
Feb;27(2):172-82.
14. Hol MK, Cremers CW, Coppens-Schellekens W, Snik AF. The Baha Softband. A new treatment for young children with bilateral
congenital aural atresia. International Journal of Pediatric Otorhinolaryngology 2005 Jul;69(7):973-80.
15. Evans A.K, Kazahaya K. Surgery or implantable hearing devices? The experts question revisited. International Journal of Pediatric
Otorhinolaryngology 2007 Mar;71(3):367-374.
16. Sheehan PZ, Hans PS. UK and Ireland experience of bone-anchored hearing aids (Baha) in individuals with Down syndrome.
International Journal of Pediatric Otorhinolaryngology, 2006 Jun;70(6):981-6.
29

References
30
17. Van der Pouw CTM, Snik AFM, Cremers CWRJ. The Baha HC200/300 in comparison with conventional bone conduction hearing
aids. Clinical Otolaryngology and Allied Sciences 1999 Jun;24(3):171-6.
18. Håkansson B, Tjellström A., Rosenhall U. Hearing thresholds with direct bone conduction versus conventional bone conduction.
Scandinavian Audiology 1984;13(1):3-13.
19. Gründer I, Seidl RO, Ernst A, Todt I. Relative value of Baha testing for the postoperative audiological outcome. HNO 2007 Sep 20.
20. Eeg-Olofsson M. Transmission of bone conducted sound in the human skull measured by cochlear vibrations. Proceedings of the
first International Symposium of Bone Conduction Hearing and Osseointegration; 2007 Jul 12-14; Halifax, Canada.
21. Bosman AJ, Snik AF, van der Pouw CT, Mylanus EA, Cremers CW. Audiometric evaluation of bilaterally fitted bone-anchored
hearing aids. Audiology 2001 May-Jun;40(3):158-67.
22. Burrell SP, Cooper HR, Reid AP, Proops DW. Patient satisfaction with bilateral bone-anchored hearing aids: the Birmingham
experience. Journal of Laryngology & Otology Suppl 2002 Jun 1;116 Suppl 28:37-46.
23. Dutt SN, McDermott AL, Burrell SP, Cooper HR, Reid AP, Proops DW. Client Speech intelligibility with bilateral bone-anchored
hearing aids: the Birmingham experience. The Journal of Laryngology & Otology 2002 Jun 1;116 Suppl 28:47-51.
24. Priwin C, Stenfelt S, Granström G, Tjellström A, Håkansson B. Bilateral Bone-Anchored Hearing Aids (Baha’s): An Audiometric
Evaluation. The Laryngoscope 2004 Jan;114(1):77-84.
25. Kompis M, Krebs M, Häusler R. Speech understanding in quiet and in noise with the bone-anchored hearing aids Baha Compact
and Divino. Acta oto-laryngologica 2007 Aug;127(8):829-35.
26. Yoshinaga-Itano C. Early Intervention after universal neo-natal hearing screening: impact on outcomes. Mental Retardation and
Developmental Disability Research Reviews 2003;9(4):252-66.
27. Tjellström A, Håkansson B, Granström G, Bone-anchored hearing aids: current status in adults and children. Otolaryngologic Clinics
of North America 2001 Apr;34(2):337-64.
28. Davids T, Gordon KA, Clutton D, Papsin BC. Bone-anchored hearing aids in infants and children younger than 5 years. Archives of
Otolaryngology-Head & Neck Surgery, 2007 Jan;133(1):51-5.
29. Papsin BC, Sirimanna TKS, Albert DM, Bailey M. Surgical experience with bone-anchored hearing aids in children. The
Laryngoscope, 1997 Jun;107(6):801-6.
30. Hol MKS, Snik AFM, Mylanus EAM, Cremers CWRJ . Does the bone-anchored hearing aid have a complimentary effect on
audiological and subjective outcomes in candidates with unilateral conductive hearing loss?, Audiology & Neurotology 2005 May-Jun;
10(3):159-68.
31. Niparko JK, Cox KM, Lustig LR. Comparison of the bone-anchored hearing aid implantable hearing device with contralateral
routing of offside signal amplification in the rehabilitation of unilateral deafness. Otology & Neurotology, 2003 Jan;24(1):73-78.
32. Powell RH, Burell SP, Cooper HR, Proops DW. The Birmingham bone-anchored hearing aid programme: paediatric.experience and
results. The Journal of Laryngology & Otology, 1996;110:21-9.
33. Catlin FI. Guide for evaluation of hearing handicap. Otolaryngologic Clinics of North America. 1979 Aug: 12(3):655-663
34. Kunst SJ, Hol MK, Cremers CW, Mylanus EA. Bone-anchored hearing aid in patients with moderate mental retardation: impact and
benefit assessment. Otol Neurotol. 2007 Sep;28(6):793-7.

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