In order to study the correlation between amplitude of the summating potential (SP) and the cochlear microphonics (CM), electrocochleograpy was performed in 23 adults with normal hearing, 26 patients with low tone sensorineural deafness, 10 patients with high tone deafness, and 34 patients with Meniere's disease. The particular correlation was not always observed between SP and CM amplitude in various inner ear conditions. In patients with Meniere's disease whose hearing disturbance were reversible, high correlation was observed between SP and CM amplitude at 0.5 and 1kHz. In these cases, it was speculated that the endolymphatic hydrops would influence the cochlea from basal turn to apical turn, and CM amplitude at 0.5 and 1kHz and SP amplitude would be increased.
