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.
What is the History ofHearing 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 communitiesTaylor/Smiley/Richards,Exceptional Students
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
Proactive action in child’s hearingproblem Commonest cause of Temporary hearing loss in children: occurs at critical stage of speech at development Leads to speech & attention difficulties
May appear hearing normally Miss certain pitches or Reacting to soundsDelay in picking up frequency in sound spectrumPrecious time lostBetween birth & 2 1/2 yearschild is programming the basic Difficult to comprehend speech at normalsystems 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
Common causes of conductivedeafness-fluid/infection
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
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
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.