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
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.