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What is Carhart's notch is seen in- and explain in detail?
Ans. is 'b' i.e., Otosclerois Pure tone audiometry in otosclerosiso Shows loss of air conduction, more for lower frequencies with characteristic rising patterno Bone conduction is normal. However in some cases, there is a dip in bone conduction curve which is maximum at 2000 Hz (2 KHz) and is called the Carhart's notcho Dip in bone conduction in otosclerosis (Carhart's notch) - 2000 Hzo Dip in noise induced hearing loss (Acoustic dip) - 4000 Hz