The pitch of electrically presented sinusoids.

A patient who uses the Ineraid cochlear implant, and who has hearing thresholds less than 50 dB HL for frequencies under 500 Hz in his nonimplanted ear, was asked to match the pitch of low-frequency signals presented to his two ears. The patient produced pitch matches, for frequencies of 125, 200, and 300 Hz presented to his most apical electrode, that were slightly higher than the reference frequency. When signals of fixed frequency were presented to electrodes located in successively more basal cochlear locations, pitch increased in an orderly fashion--an average of 57 Hz (range = 31-87 Hz) for each change in electrode location.