Effects of frequency-to-place mismatch in children listening to simualted unilateral and bilateral cochlear implant configurations

Binaural cues are important for spatial speech recognition. While binaural cues can be partly restored by bilateral cochlear implants or a unilateral cochlear implant in patients with single-sided deafness, the benefits may be limited by frequency-to-place mismatch in both cases. Previous studies reported worse recognition of spatially separated speech as frequency-to-place mismatch increased in typical-hearing adults listening to acoustic simulations of bilateral cochlear implants (Thomas et al., 2022). This work also revealed that children were more sensitive to the spectral degradation and less able to use spatial cues for spatial speech recognition. The present study investigates the effects of frequency-to-place mismatch on binaural fusion in typical hearing children (7–9 years old) listening to acoustic simulations of bi- and unilateral cochlear implant configurations. The stimuli in the left ear were either unprocessed or processed by a 16-channel sinewave vocoder with a fixed insertion depth while the stimuli in the right ear were processed by 16-channel sinewave vocoders with varying insertion depth. Speech recognition threshold results from N = 10 children show an effect of interaural insertion depth mismatch upon speech recognition thresholds, with no differences by age. Comparisons with adult data will likewise be reported.