Abstract for ICA 2007, Madrid, Invited talk in session on Applications of Psychoacoustics Auditory scene analysis and the precedence-effect with cochlear implants - Predictions from simulations Bernhard U. Seeber The analysis of auditory scenes is based on the evaluation of monaural spectral and temporal cues as well as on binaural cues. Using current devices cochlear implant (CI) subjects have very limited access to interaural time differences (ITDs) and spectral information while interaural level cues (ILDs) and the temporal envelope are relatively well reproduced. Localization in quiet is often possible but the presence of other sounds disturbs it. We previously showed that the precedence-effect was disturbed for ongoing sounds and lead and lag images were heard in separation. This was seen with patients and also with a noise-band vocoder CI-simulation. The present study shows that temporal quantization of the vocoded envelope has no effect on precedence. Further study varied the interaural match of the carrier frequencies in a sinusoidal vocoder. Precedence broke down if carriers were not matched in frequency. However, for zero or small frequency offsets some subjects showed precedence and fusion into one image. Interestingly, the interaural phase of the carrier played only a limited role which shows that precedence of ongoing sounds can solely be based on ILDs and envelope-ITDs. The results suggest that proper place matching of CI-electrodes would help the analysis of concurrent sounds. PACS: 43.66.Pn - Binaural hearing