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The normal summating potential recorded from external ear canal.

A C Coats
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Abstract

With a "plastic leaf" electrode, cochlear summating potential (SP) and auditory nerve action potential (AP) responses to rectangular-pulse clicks were recorded from the ear canal skin surface of 96 normal-hearing ears of 48 subjects. The main goals of this investigation were to develop a more precise characterization of the relationship between SP and AP amplitudes across normal ears and to determine the confidence limits of this relationship so that a more accurate "normal limit" could be established for clinical testing. The results suggest that the across-subjects SP-AP amplitude relationship is linear. Also, SP scatter increases as AP amplitude increases, but the scatter is equalized by log transforming the data. The distance of the SP from the log-transformed SP-AP estimating line in SE ("AP-normalized SP amplitude") was found to be superior to the SP/AP amplitude ratio as a method of adjusting SP to AP amplitude, because the SP/AP ratio varied significantly with AP amplitude both across subjects and with different ear canal electrode positions.

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Action PotentialsAdolescentAdultAgingCochlear Microphonic PotentialsEar CanalElectrodesEvoked Potentials, AuditoryFemaleHumansMaleMathematicsSex FactorsVestibulocochlear NerveJournal ArticleResearch Support, Non-U.S. Gov'tResearch Support, U.S. Gov't, P.H.S.

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A C Coats. 1986. The normal summating potential recorded from external ear canal.. https://doi.org/10.1001/archotol.1986.03780070071016

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