Degree of hearing loss Based on PTA in 500, 1k, 2K HZ (WHO 1980 criteria) Mild HL(<40 dB) Middle HL(41-55dB) Middle-severe HL(56-70 dB) Severe HL 71-90dB) Profound HL(>90 dB)
Degree of hearing loss ◼ Based on PTA in 500, 1k, 2k Hz (WHO 1980 criteria) ◼ Mild HL (<40 dB) ◼ Middle HL (41-55dB) ◼ Middle-severe HL (56-70 dB) ◼ Severe HL (71-90 dB) ◼ Profound HL (>90 dB)
Conductive hearing loss Pathogen Infection Trauma EAC Obstruction(foreign body, cerumen, tumor) Deformation ( aural atresia malformation of ossicular chain, dysplasia of oval or round window 1. Eardrum rcutar canals B Vestibular nerve Note Eustachian tube
Conductive hearing loss ◼ Pathogen ◼ Infection ◼ Trauma ◼ EAC Obstruction (foreign body, cerumen, tumor) ◼ Deformation (aural atresia, malformation of ossicular chain, dysplasia of oval or round window
Conductive hearing loss Location Deformation of auricle 3dB) s semicircular u Stenosis and autrsia of EAC(45- 60dB) Vestibula TM lesion(30-45 dB) Cochlea nerve Dysfunction of ossicular chain (50dB) Dysfunction of Eustachian tube (60dB) Lymphatic fluid dysfunction
Conductive hearing loss ◼ Location ◼ Deformation of auricle (3dB) ◼ Stenosis and autrsia of EAC (45- 60 dB) ◼ TM lesion (30-45 dB) ◼ Dysfunction of ossicular chain (50dB) ◼ Dysfunction of Eustachian tube (60dB) ◼ Lymphatic fluid dysfunction
Conductive hearing loss u Diagnosis u Tuning fork RI: negative WT: lesion side ST: prolongation ter fann 阳a33C1B0 PTA Bone threshold: normal o Air threshold 25-60 dB Image stud 00000n0一 0p00000009 100 110 10
Conductive hearing loss ◼ Diagnosis ◼ Tuning fork ◼ RT: negative ◼ WT: lesion side ◼ ST: prolongation ◼ PTA ◼ Bone threshold: normal ◼ Air threshold: 25-60 dB ◼ Image study