<prompt> What should be the loss of hearing at least for Webers test to lateralise?5 db10 db15 db20 db  <response>: Ans. a 5 db. Ref. Diseases of ENT by PL Dhingra, 2nd ed., 26; 3rd ed., 30 Lateralization of sound in Weber test, a tunning fork of 512 Hz implies a conductive loss of 15-25 dB in ipsilateral ear or a sensorineural in contralateral ear. However as less as 5 db hearing loss can cause lateralization of Webers test. A negative Rinnes test indicates a minimum air-bone gap of 15-20 db. TestNormalConductive deafnessSensorineural deafness1Rinnes testAC BC Rinne BC AC Rinne -AC BC2Webers testNot lateralisedLaterlized to poor earLateralized to better ear3ABCSame as examinersSame as examinersReduced4Schwabachs testEqualLengthenedShortened 