The intelligibility of a 16-item consonant set was assessed for 10 patients who use the Symbion four-channel cochlear implant. The patients were selected on the basis of "good" speech recognition scores. For each patient, consonant intelligibility was assessed when his/her processor was configured to pass from one to four channels of information. The results suggest, most generally, that two channels, one low frequency and one high frequency, provide most of the information about consonant identity.