The main goal of this study was to systematically investigate place-pitch perception in electrical hearing and the relative relationship between place-pitch perception ability, speech understanding and musical pitch discrimination by cochlear implant (CI) users. Electrode pitch ranking test was carried out to evaluate the place-pitch perception ability of CI users. Four post-lingually deafened CI users were recruited. They also participated in the speech recognition test and musical pitch discrimination test. Results showed that place pitch were generally ordered from apical to basal electrodes. The apical electrodes were judged lower in pitch than basal electrodes. Large individual difference was found. Comparing pitch and speech performance, the speech recognition result was related to the place-pitch perception ability of CI users, but this relationship was limited by the ceiling effects. However, a correlative relationship was found between musical pitch discrimination result and place-pitch ability of CI users. It indicated that the current signal processing of CI system can provide sufficient information for speech understanding but not for music perception of CI users. To a certain extent, music perception of CI users was determined by their place-pitch abilities.
The main goal of this study was to systematically investigate the relative contribu- tion of spectral resolution and temporal envelope periodicity to musical pitch discrimination. Stimuli from four instruments (clarinet, trumpet, piano and violin) and synthetic complex tone were utilized. A noise-excited vocoder was used to control the spectral resolution and temporal envelope periodicity of the musical stimuli. Ten normal-hearing subjects were recruited for the study. Psychoacoustic experiments on pitch discrimination were carried out. Results showed that the spectral cue was important for musical pitch discrimination. Relative good perfor- mance could be achieved when there were 16 frequency channels. No clear effect was found for the temporal envelope periodicity to pitch discrimination.