Musical Harmony in Electric Hearing

A cochlear implant (CI) restores hearing for profoundly deaf patients by transmitting sound to an array of electrodes that stimulates the inner ear. The small number of frequency bands and limited transmission of temporal fine structure affects the music perception. The present work investigates the pleasantness of chords and chord sequences in adults using such electric hearing. In the first task, participants compared chord types according to their perceived pleasantness. Normal-hearing listeners judged the major chord and the minor chord as the most pleasant ones compared to other chord types. CI users appraised the major chord as more consonant than other chord types. The second task used four-chord sequences, half of which ended on an authentic V-I cadence. In the other presentations, the final tonic was replaced either by a transposed major chord or by a dissonant chord. The participants had to judge whether the ending was conclusive. While normal-hearing listeners preferred authentic cadences, all but one CI user assessed the modified cadences as similarly satisfying. The results indicate that CI users appreciated consonance of isolated chords to a certain extent similar to normal-hearing listeners. Nevertheless, the majority of CI users fail to register the musical syntax in the harmonic progression of cadences.