1. Dr Sheelu Srinivas
Consultant ENT Surgeon

2. Statistics about hearing loss
 Hearing loss is the third leading chronic disability
following arthritis and hypertension.
 9 out of every 10 children who are born deaf are born
to parents who can hear.
 profound hearing disability in India is about one
million
 1.2 million people with severe hearing disability
 0.9 million people with moderate hearing disability
and 7.1 million people with very mild hearing
disability.

3. What is the History of
Hearing Impairments?
 Denied legal and human rights as well as education and
social interaction
 1500-1600’s - Spanish began teaching deaf individuals to
communicate.
 1700s - First free public schools for deaf individuals began
in France.
 1864 - A. Lincoln authorizes the National Deaf-Mutes
College to grant degrees; the institution later becomes
Gallaudet University.
 Late 1800s - Oralist movement
 20th Century – Advocacy for protection of individual rights
and access to inclusion in schools and communities
Taylor/Smiley/Richards,
Exceptional Students

4. Development Timing
 Week 3 - otic placode, otic vesicle
 Week 5 - cochlear part of otic vesicle elongates (humans 2.5
turns)
 Week 9 - Mesenchyme surrounding membranous labrynth
(otic capsule) chondrifies
 Week 12-16 - Capsule adjacent to membranous labrynth
undegoes vacuolization to form a cavity (perilymphatic
space) around membranous labrynth and fills with
perilymph
 Week 16-24 - Centres of ossification appear in remaining
cartilage of otic capsule form petrous portion of temporal
bone. Continues to ossify to form mastoid process of
temporal bone.
 3rd Trimester - Vibration acoustically of maternal
abdominal wall induces startle respone in fetus.
 (These are Human embryonic timings, not clinical which is
based on last menstral period +2 weeks)
 3 Sources:
 Inner ear - epidermal otic placode at level of hindbrain.
 Middle ear - cavity: 1st pharyngeal pouch, ossicles:
mesenchyme 1st and 2nd pharyngeal arches.
 Outer ear - external auditory meatus: 1st pharyngeal cleft,
auricle: 6 hillocks 1st and 2nd pharyngeal arches

5. Proactive action in child’s hearing
problem
 Commonest cause of Temporary hearing loss in
children: occurs at critical stage of speech at
development
 Leads to speech & attention difficulties

6. May appear hearing normally
Miss certain pitches or
Reacting to sounds
Delay in picking up frequency in sound spectrum
Precious time lost
Between birth & 2 1/2 years
child is programming the basic Difficult to comprehend speech at normal
systems volume
Confused about things in their
Misunderstand or
environment
Hearing loss tricky to spot & give impression of a
slow learner
Actually certain sounds do not Brain does not get complete
reach the brain picture

7. Common causes of conductive
deafness-fluid/infection

8. Primary acquired cholesteatoma

10. Managing hearing loss
 Conductive- Myringotomy, Tympanoplasty,
Stapedotomy,
 Mastoid surgery
 Sensorineural - Hearing aids, BAHA, Cochlear
Implants

11. Sensorineural hearing loss
 Abnormality of inner ear & auditory nerve
 Majority of the cases inner ear hair cell damage-
Cochlear Implant
 Auditory nerve damage -Brain stem implant

12. The Deaf Community
 Supportive, strong
community
 Does not view hearing
loss as a disability
 Rich history and
language (e.g., ASL)
 Children with cochlear
implants may have
limited access to the
Deaf community

13. Cochlear Implant
 Bionic ear
 Hearing is the only special sense which is conquered
 Electronic device when implanted provides sense of
sound
 The cochlear implant is the most significant technical
advance in the treatment of hearing impairment since
the development of the hearing aid around the turn of
the century.

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