Impedance audiometry is done using frequency probe of
It consists of a probe which fits into the external acoustic canal and has 3 channels: To deliver a tone of 220Hz To pick up the reflected sound a microphone To bring about changes in air pressure in the canal from positive to normal and then negative Ref: Dhingra; 6th Edition; pg no 24
220 Hz
555 Hz
440 Hz
1000 Hz
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