The document summarizes bone conduction hearing aids and the BAHA (Bone Anchored Hearing Aid) system. It discusses indications for BAHA, the surgical procedure, outcomes, advantages over conventional hearing aids, and limitations. BAHA provides an alternative for those who cannot use air conduction hearing aids due to ear canal issues or single-sided deafness. The surgery attaches a fixture to the skull bone which integrates and allows mounting of a sound processor externally on an abutment.

1. Presenter-Dr Utpal
Moderator-Dr S.Mandal
Co –Moderator-Dr Nihar
VMMC & Safdarjung Hospital

2.  BAHA is the registered trademark of bone
conduction hearing aid system currently
manufactured by COCHLEAR .

3.  TITANIUM FIXTURE
 TITANIUM ABUTMENT
 SOUND PROCESSOR

6. TITANIUM FIXTURE
• SURGICALLY EMBEDDED IN SKULL BONE
• BONDS WITH SORROUNDING TISSUE
(OSSEOINTEGRATION).
TITANIUM ABUTMENT
• EXPOSED OUTSIDE SKIN.
SOUND PROCESSOR
• ATTACHED TO ABUTMENT ONCE
OSSEOINTEGRATION IS COMPLETE
• TAKES 2-6 MONTHS AFTER IMPLANTATION.

7. 1 . When air-conduction (AC) hearing aid cannot be
used:
Canal atresia, congenital or acquired, not amenable to
treatment.
• Chronic ear discharge, not amenable to treatment.
• Excessive feedback and discomfort from
air-conduction hearing aid.
2. Conductive or mixed hearing loss, e.g. otosclerosis
and tympanosclerosis where surgery is
contraindicated.
3. Single-sided hearing loss.

8.  People with chronic infection of ear canal and
cannot wear standard " in the ear" air -
conduction hearing aids.
 Children with malformed or absent outer ear and
ear canals as in microtia or canal atresia.
 Single-sided deafness.

9.  Prime requirement is that there should be
adequate bone conduction,pure tone thresholds.
 B.C averaged over .5,1 ,2 &3 khz should be
equal to or better than 45 db .
 Pre op speech audiometry to identify those with
poor speech comprehension(contraindication)

10.  Can be performed under LA or GA.
 Single stage surgery in adults.
 3 months are allowed for osseointegration
before sound processor can be attached.
 2 staged procedure in children.
 6 months allowed for osseointegration
 2nd stage operation is done to connect the
abutment through the skin to the fixture.

11.  Dural damage in children with craniofacial
anomaly.
 The most common long term problem is crusting
and inflammation around the peg. Sometimes it
progresses to granulation tissue formation.
 Screw failing

12.  Advantages of BAHA in comparision to conventional
bone conduction aids:
 Cosmetically more acceptable
 More comfortable to wear.
 Gives better ,less distorted amplification.
Superior hearing is supported audiometrically by better
aided thresholds,particularly at higher frequencies and
by better speech quality.

13.  Poorer speech reception thresholds and
discrimination .
 Those with smaller A-B gap are particularly
likely to have poorer outcome with a BAHA.
 Most patient who previously wore an air
conduction aid, but were troubled by discharge
,report that with BAHA the discharge improved.

14.  CONCLUSION: If a patient is benefiting
acoustically from an air conduction aid then
the disability from the wearing of an ear
mould has to be sufficiently great for a BAHA
to be substituted as this may give poorer
acoustic benefit

15.  b/l BAHA will stimulate the auditory system in a
very different way from b/l air conduction aids.
 The cues that are used centrally to enable spatial
hearing will therefore be materially different
with b/l BAHA.
 Whether the central auditory system can adapt to
this and gain the same benefit as from binaural
air conduction aids is unlikely.

16.  A small case series report audiometric
improvement in those with a non congenital
conductive impairment of sound localisation and
speech recognition in noise with spatial
separation of the sound sources.
 Whether such benefits equates to alternative of an
air conduction aid has not been shown.

17.  Individual with severe problems with the ear
mould (otitis externa),that makes it difficult
to use an A.C . Aid,then a BAHA is alternative.
 BAHA does indeed overcome the ear mould
problems, but often at the price of lesser
audiometric benefit.

18.  Traditional way to aid such a patient is
CROS(Contralateral Routing Of Sound)
 Limited benefit because good ear finds it difficult
to separate the two different sound inputs.
 A BAHA is likely to be subject to the same
problem,albeit the good ear is not occluded with
an ear mould.

19.  The generic Glasgow Hearing Aid Benefit
Profile has been used to compare the benefit
and residual disability between a BAHA and
the patient’s previous aid.
 Although BAHA was reported to be materially
superior,the benefit from a BAHA was almost
certainly overestimated .

20.  The benefit from BAHA is comparable to the
benefit of middle ear surgery and
conventional air conduction hearing aids.
 The benefit was greatest for those with
congenital atresias that has previously used a
bone conduction aid.

21.  The main impetus to develop these devices has
come from patient dissatisfaction with
conventional amplification aids.

22.  Better sound quality.
 No occlusion effects/acoustic feedback
 More comfortable.
 No Cosmetic implication
 No effect of wax /otitis externa

23.  Vibrant soundbridge
 Otologics middle ear transducer
 Esteem hearing implant

24.  It is an active semi implantable hearing device.
 Parts:
 VORP(vibrating ossicular prosthesis)-internal
surgically implanted part.
 Components:receiving coil,conductor link and
transducer.
 Audio processor(external)

25.  Transducer employs a small electromagnetic
coil and a enclosed magnet to produce
vibrations in this floating mass transducer
which is coupled to long process of incus.

26.  Fully implantable device.
 COMPONENTS:microphone(subcutaneous),rec
eiver and transducer.
 The transducer drives a probe(ALUMINIUM
OXIDE) connected to body of incus

27.  FULLY IMPLANTABLE PIEZOELECTRIC DEVICE.
 THE DEVICE COMPRISES OF PIEZO ELECTRIC
SENSOR ON INCUS BODY AND DRIVER
CEMENTED TO STAPES HEAD.
 IMPLANTION REQUIRES REMOVAL OF
LENTICULAR PROCESS OF INCUS.

28.  Most suitable for mild to severe SNHL.
 Hearing loss should ideally be a stable one.
 SOUNDBRIDGE DEVICE HAS BEEN proposed for
use in conductive or mixed losses in
combination with passive middle ear
prostheses(PORP/TORP/STAPES PISTON)

29.  Tympanometry and acoustic reflexes required
to assess middle ear function and speech
audiometry to assess retrocochlear loss.
 Worst ear is usually selected for implantation.

30.  Normal audiological function is the classical
indication for soundbridge device.
 Absence of retrocochlear or central
involvement .
 When middle ear function is abnormal
,middle ear inflammation must be controlled.

31.  Incisions used:extended endaural,post
aural,extended post aural.
 Cortical mastoidectomy and then a posterior
tympanotomy.
 An implant bed is drilled in the squamos temporal
bone to accommodate the internal receiver and
conductor link.
 The floating mass transducer is placed in the
middle ear via the posterior tympanotomy with its
attachment clip around the long process of incus.

32.  European 10 centre trial(47 patient)
 No major complication in term of permanent
facial weakness or profound snhl reported.
 Only delayed onset temporary partial facial
weakness occouring 10 days post surgery was
reported.
 Damage to chorda tympani.(15%)
 Tinnitus (1%)

33.  No significant deterioration in average unaided
pure tone thresholds in the implanted ear.
 Speech recognition was also measured and
correlated well with the gain attained ,implying
that the quality of the amplification was
adequete for speech recognition.

34.  APHAB (Abbreviated Profile Of Hearing Aid
Benefit),self assessment questionnaire has
been used to compare patient satisfaction
with their conventional aid to the vibrant
soundbridge by Fraysse et al after 3 months
in 17 of their patient.
 Twelve reported a significant improvement,4
were unchanged and one was worse.