Effects of acoustic trauma on the cochlear potentials

The cochlear microphonic, summating potential, and action potential were recorded from all three turns of the gerbil cochlea prior to and following a 1-h exposure to a high-intensity pure tone. Results proved that the depression in the cochlear microphonic was greater when recorded from the upper two turns of the cochlea. The losses for the summating potential were not dependent on recording location. Although the cochlear microphonic and to some extent, the negative summating potential, reflected locally generated activity from the hair cells, the positive summating potential appeared to be dependent on distant electrical activity.