[Relations between the summation potential and frequency selectivity]

In cases of inner ear diseases, e.g.m. Ménière, summation potential (SP) can be measured using the extratympanic elektrocochleographic method. This potential is a consequence of hydrops in the cochlea. In 128 patients with confirmed SP, it was also possible to measure frequency selectivity (FS) using the psychoacoustic method. Reduced FS was found to a greater or lesser degree in the basal and apical turn of the cochlea. It can be assumed that both phenomena are to be attributed to the same cause.