Human auditory nerve responses: a comparison of three commonly used recording sites

The computer-averaged N1 response from humans to click stimuli was compared at three recording sites -- dermal and subdermal electrodes in the ear canal, and a transtympanic electrode on the promontory. A total of 26 subjects, some of whom were measured at all three sites, participated in 47 experiments. The promontory electrodes were consistently more sensitive and yielded cleaner N1 waveforms than did the ear canal sites. In considering the clinical use of N1 averaging, the advantages of the transtympanic method outweigh the risks. While a few persons yield reasonable good ear canal potentials, the reliablitity of this method in general application is inadequate and unpredictable.