Investigating cochlear implant place-pitch perception with the Modified Melodies test

There has been speculation that cochlear implant place-of-excitation cues could be more akin to the brightness attribute of timbre (the spectral profile) than to melodic pitch. As brightness can be ordered on a low-to-high scale, it would allow high scores on pitch-ranking tests. In contrast, the Modified Melodies test measures pitch perception in a melodic context. In each trial, a familiar melody was presented twice. In one presentation, randomly selected, the pitch was deliberately modified. The subject's task was to select the un-modified melody. Six Nucleus implant recipients were tested with melodies presented as pure tones in the frequency range C5-C6 (523-1046 Hz) through the ACE strategy on the Freedom processor. All subjects were able to identify incorrect melodic contours and three subjects were able to recognize errors in musical intervals. These results are consistent with the hypothesis that cochlear implant place cues alone are sufficient to convey a melody.