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What is Carhart's notch in otosclerosis is observed at: (Repeat) and explain in detail?
Ans: B (2000HZ) Ref: Diseases of the Ear Nose and Throat by PL Dhingra 5th edn .2010.pg 97-100Explanation:Carhart's notchCarhart's notch is classically seen as a dip centered around 2 kHz range of hone conduction curve audiometery.This feature is seen in patients with otosclerosis.This notch will disappear after a succesful stapedotomyThere is also effective improvement in the patient's level of hearing at 2 KHz frequency levels.