The coding of pitch in modern cochlear implant devices is challenging for recipients as it is mainly based on place pitch, which is subject to the location of a finite number of electrodes on an array. The coding of pitch via temporal cues in the stimulation may help to improve pitch perception since most cochlear implant subjects are able to perceive rate changes on a single electrode up to around 300 Hz. Some optimally performing subjects are able to perceive temporal pitch up to 1000 Hz. However, performance varies highly between subjects and depends on the selected electrodes. The first objective of this study was to quantify the effect of electrical dynamic range on temporal pitch perception. Therefore pitch ranking was measured on electrodes with the widest and the narrowest dynamic ranges. The second objective was to investigate the effect of the location of the electrodes on pitch ranking and therefore a basal, a middle and an apical electrode were additionally tested for each subject. The results show a high degree of intersubject variability. However, the electrical dynamic range was found to correlate with the pitch ranking score. No consistent effect was observed based on location on the implant array. Improving CI performance based on individual subject and electrode performance might be the key to better understanding of the mechanisms behind temporal pitch perception and it could lead to improved language and music perception.
ASJC Scopus subject areas
- Biomedical Engineering