What method effectively eliminates the cochlear microphonic from the electrocochleographic response?

What method effectively eliminates the cochlear microphonic from the electrocochleographic response?

• A. Increasing the distance between transducer and electrode sites
• B. Using insert earphones to eliminate artifact
• C. Using ipsilateral masking to enhance the compound action potential
• D. Using alternating polarity clicks

Answer: (D)

The main idea is that the cochlear microphonic is a hair-cell receptor potential that mirrors the stimulus and reverses in sign when the stimulus polarity is flipped. By using alternating polarity clicks and averaging the responses, the microphonic components cancel out because they invert with polarity, while the neural response from the auditory nerve (the compound action potential) does not invert in the same way and remains. This makes alternating polarity an effective method to reduce or eliminate the cochlear microphonic and reveal the underlying neural response in electrocochleography.

The main idea is that the cochlear microphonic is a hair-cell receptor potential that mirrors the stimulus and reverses in sign when the stimulus polarity is flipped. By using alternating polarity clicks and averaging the responses, the microphonic components cancel out because they invert with polarity, while the neural response from the auditory nerve (the compound action potential) does not invert in the same way and remains. This makes alternating polarity an effective method to reduce or eliminate the cochlear microphonic and reveal the underlying neural response in electrocochleography.