I am slightly confused if OAE and Cochlear microphonic both measures the function of outer hair cells. If OAE is absent and CM is present, how does CM records a response but OAE does not, it seems confusing and contradicting between both tests?
Hi there! I forwarded your question to one of our audiologists, and he answered: OAEs and Cochlear microphonics are both thought to generate from the outer hair cells. But, the recording methods are very different. OAEs rely on the acoustic transfer of the emission back to the ear canal where it is picked up by the probe microphone. This rely on good middle ear function. Cochlear Microphonics are recorded by electrodes (on the surface of the skin in the case of newborns as discussed here) and therefore can be recorded when there is poor middle ear function. Best regards, Shane
I am slightly confused if OAE and Cochlear microphonic both measures the function of outer hair cells. If OAE is absent and CM is present, how does CM records a response but OAE does not, it seems confusing and contradicting between both tests?
Hi there!
I forwarded your question to one of our audiologists, and he answered:
OAEs and Cochlear microphonics are both thought to generate from the outer hair cells. But, the recording methods are very different. OAEs rely on the acoustic transfer of the emission back to the ear canal where it is picked up by the probe microphone. This rely on good middle ear function. Cochlear Microphonics are recorded by electrodes (on the surface of the skin in the case of newborns as discussed here) and therefore can be recorded when there is poor middle ear function.
Best regards,
Shane