[Acoustically induced slow vertex potentials of patients with single channel inductive cochlear implant]

Acoustically induced slow vertex potentials (SVP) of 12 patients with single channel inductive cochlear implant were recorded in order to objectively evaluate the effect of this device on rebuilding hearing ability of totally deaf patients. We have found that the shape of SVP in patients was the same as that in healthy person and the average latency of every wave evoked by clicks of maximal comfortable loudness was close to those evoked by 60 and 70 dB nHL clicks in healthy people, but the average dynamic range was only 15 dB, and became smaller when the active electrode was put on the round window membrane. All these objectively prove that the acoustic stimulation elicited by single channel inductive cochlear implant is strong enough to activate the residual spiral ganglion cells and produce auditory sensation in cerebral cortex via the same central pathway as it is in the healthy.