You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is In audiogram of an otosclerotic patient, Carha's notch is a dip at __________ and explain in detail?
Caraha's notch: Is classically found in bone conduction audiograms of patients with otosclerosis. This is actually a dip centered around 2000 Hz. Some authors consider carha's notch to be an aifact. This notch is closely related to the carha's effect.Carha's effect: was initially described following successful stapes surgery. There was an over closure of air bone gap following successful surgery. Classically this effect lead to an improvement in hearing levels paicularly at 2 KHz frequency levels.