Combining current focusing and steering in a cochlear implant processing strategy

Objective: To evaluate the benefit of combined current focusing and steering to speech recognition in noise with cochlear implants (CIs). Design: Combined current focusing and steering was implemented using focused partial tripolar (pTP) mode with two current steering ranges. The two pTPsteering strategies were compared to a monopolar (MP) strategy without current focusing or steering and a pTP strategy with only current focusing using the Hearing in Noise Test. The strategies differed only in stimulation mode. Study sample: Ten post-lingually deafened adult CI users participated in this study. Results: Compared to the MP strategy, both pTPsteering strategies produced significantly better speech reception thresholds, while the pTP strategy did not. Subjects with better baseline MP performance had less improvements with the pTPsteering strategies. All four strategies were experimental low-rate strategies and none of them outperformed subjects’ clinical strategies. Conclusions: Speech recognition in noise was better with the pTPsteering strategies than with the MP strategy, but the effect of pTP-mode current steering on spectral resolution is yet to be tested.