A preliminary investigation comparing one and eight channels at fast and slow rates on music appraisal in adults with cochlear implants

Music perception is important to cochlear implant patients, but little effort has been devoted to improving signal processing for music. In this preliminary investigation, we probed the importance of number of channels and stimulus rate. We asked eight users of the Clarion cochlear implant to rate music quality on a scale from 0 to 100 on three different types of music (country and western, pop and classical). Patients rated eight- and one-channel processors running at a fast and slow rate. The stimulus rate was 200 pps for the slow rate. For the eight-channel condition, the fast rate varied from 394 to 765 pps. For the one-channel condition, the fast rate varied from 2601 to 4335 pps. Results indicated that the eight-channel condition was uniformly rated higher than the one-channel condition. However, the results for stimulus rate were less clear. No patients assigned higher ratings with the slow rate, but only three subjects assigned higher ratings with the fast rate. We conclude that music perception can be influenced and probably improved by signal processing. The number of channels, or perhaps spectral representation, is critical for music appreciation by cochlear implant recipients.