Related Experiment Video
Updated: Aug 6, 2026
Systematic Hearing Performance Evaluation Process for Adolescents with Cochlear Implantation at Early Ages
Published on: March 24, 2023
Temporal and speech outcomes in bimodal cochlear implant users: The effect of device delay mismatch
Gökçe Gültekin1,2, Halide Çetin Kara3, Eyyup Kara4
1Department of Audiology, Faculty of Health Sciences, Üsküdar University, Istanbul, Turkey. gokce.gultekin@uskudar.edu.tr.
Purpose:
The aim of this study is to characterize and compare the spectral-temporal features of speech, processing performance, and speech perception in noisy environments among bimodal cochlear implant (CI) users. Additionally, the study aims to examine intra-individual differences in synchronous and asynchronous use among individuals in whom the delay mismatch between the hearing aid (HA) and the CI has been reduced.
Methods:
Forty-one bimodal cochlear implant users aged between 15 and 45 years participated in the study. Participants were divided into two groups based on the presence of the temporal synchronization (20 Cochlear, 21 MED-EL). In the first session, asynchronous data were collected using the Modulation Detection Threshold Test (easyMDT), Random Gap Detection Test (RGDT), Spectral-temporally Modulated Ripple Test (SMRT), and Turkish Matrix Test (TMT). For MED-EL users, the CI and HA were made temporally synchronized using a bimodal synchronization setting. In the second session, two CI programs were created, and all tests were repeated for synchronized fitting. In the programs, only the CI's speech processing strategies were used differently (HDCIS only and a combination of FSP and HDCIS).
Results:
Within the MED-EL users, synchronous mode comparisons demonstrated that the program using both strategies yielded improvements: a 2.3 ms reduction in RGDT composite score, a 1.31 dB decrease in easyMDT modulation detection threshold, a 5.56 dB SNR improvement in the Adaptive procedure of TMT, and a 6% increase in the Non-Adaptive procedure of TMT (p < 0.05).
Conclusions:
In conclusion, the exploratory analysis suggests a possible relationship between temporal synchronization in bimodal CI use and outcomes related to temporal processing and speech perception in noise. Given the variability in inter-individual parameters, these findings should be considered preliminary and interpreted cautiously until confirmed by future controlled or longitudinal studies.