Deafness and its rehabilitation Chunfu dai m,d ph. d
Deafness and its rehabilitation Chunfu Dai M.D & Ph.D
Background Speech frequency 500-3000Hz Normal hearing Sound conduction Sound perception( cochlea) Sound analysis(retro-cochlea) Deafmutism Profound hearing loss No language speech perception Language development quit(6M-6Y) Postlingual deafness deafness present following language developed
Background ◼ Speech frequency 500-3000Hz ◼ Normal hearing ◼ Sound conduction ◼ Sound perception (cochlea) ◼ Sound analysis (retro-cochlea) ◼ Deafmutism: ◼ Profound hearing loss. ◼ No language speech perception ◼ Language development quit (6M-6Y) ◼ Postlingual deafness ◼ deafness present following language developed
Morbidity 1/1000 in new born baby 1/100 in younger 14/100 in middle age 30/100 in 65-75 year old(presbycusis) 50/100 in >75 year old
Morbidity ◼ 1/1000 in new born baby ◼ 1/100 in younger ◼ 14/100 in middle age ◼ 30/100 in 65-75 year old (presbycusis) ◼ 50/100 in >75 year old
Classification Conductive deafness Sensorineural deafness Sensory deafness Lesion located in cochlea cochlear deafness) Nervous deafness a Lesion located in retrocochlear(retrocochlear deafness) Mixed deafness 1. Eardrum 5 Semcretear canals-B Vestibular nerve dal Nerve 4 SIDes
Classification ◼ Conductive deafness ◼ Sensorineural deafness ◼ Sensory deafness ◼ Lesion located in cochlea ( cochlear deafness) ◼ Nervous deafness ◼ Lesion located in retrocochlea (retrocochlea deafness) ◼ Mixed deafness
Classification Congenital deafness Hereditary deafness a Non hereditary deafness Acquired deafness Prelingual deafness Postlingual deafness
Classification ◼ Congenital deafness ◼ Hereditary deafness ◼ Non hereditary deafness ◼ Acquired deafness ◼ Prelingual deafness ◼ Postlingual deafness