Clinical Research Directory

Inclusion Criteria: Normal group 1. Thai adults (18-60 years old) 2. Pure-tone air-conduction thresholds ≤ 25 dB HL, measured at audiometric frequencies 250, 500, 1000, 2000, 3000, 4000, 6000 and 8000 Hz and air-bone gab \< 10 dBHL at frequencies 500, 1000, 2000 and 4000 Hz 3. Type A tympanogram with present ipsilateral acoustic reflex 4. No diagnosis of middle ear disease 5. No history of middle ear surgery 6. Normal finding in otoscopic examination Conductive hearing loss group 1. Thai adults (18-60 years old) 2. Pure-tone air-conduction thresholds \> 25 dB HL, measured at audiometric frequencies 250, 500, 1000, 2000, 3000, 4000, 6000 and 8000 Hz and air-bone gab \> 10 dBHL at frequencies 500, 1000, 2000 and 4000 Hz at least 2 frequencies in one ear 3. Type A, As or Ad tympanogram with absent ipsilateral acoustic reflex 4. Normal finding in otoscopic examination 5. There is an appointment for exploration middle ear within 2 months Exclusion Criteria: 1. Have previously had middle ear surgery 2. Have an earache 3. Type B or C tympanogram 4. Volunteers who do not cooperate in audiometry test or unable to do audiometry test