5aPP9. Perception of musical pitch with electrical stimulation of the cochlea.

Session: Friday Morning, May 17

Time: 11:30

Author: Hugh J. McDermott
Author: Colette M. McKay
Location: Dept. of Otolaryngol., Univ. of Melbourne, Parkville, 3052 Australia


For cochlear implant users to obtain enjoyment from music, it is essential that they be able to perceive melodic pitch. Previous studies have indicated that the ``pitch'' or timbre of pulsatile electrical stimuli varies with the repetition rate or intracochlear site of delivery, but generally pitch has been defined loosely as a tonal quality that can be ranked in terms of ``sharpness.'' In a recent series of experiments, a user of the Nucleus 22-electrode implant was asked to judge or adjust the musical interval between pairs of stimuli. The electrical parameters investigated included the frequency of sinusoidally amplitude-modulated pulse trains, as well as pulse rate and active electrode position. The subject was able to judge the pitches using only the interval names (``fifth'' ``octave,'' etc.), and without specific training, the guidance of familiar melodies, or rhythm cues. The results showed that rate or modulation frequency could convey musical pitch over a range of approximately two octaves, and followed a relationship comparable with that for acoustic stimuli and normal hearing. The pitch related to electrode position could also be labeled in musical terms. Interestingly, when both place and rate varied together, the pitch associated with electrode position was generally dominant.

from ASA 131st Meeting, Indianapolis, May 1996