Determining the minimum number of electrodes that need to be pitch matched to accurately estimate pitch matches across the array

Abstract

Objective: With bilateral cochlear implant (CI) users there is typically a place mismatch between the locations stimulated by the left and right electrode arrays. This mismatch can affect performance, potentially limiting binaural benefits. One way to address this is by perceptually realigning the arrays such that a given frequency in the input stimulates perceptually matched locations in the two ears. A clinically feasible technique is needed that can determine the appropriate perceptual alignment. A pitch matching task can potentially be used for this, but only if it can be performed in a clinically feasible amount of time. The objective of this study was to determine the minimal number of electrodes that need to be pitch matched to accurately determine pitch matches across the entire array. Design: A retrospective analysis of pitch matching data was conducted. Subsets of pitch matches were selected and the predicted pitch matching across the array was compared to that predicted by the full dataset. Study sample: 16 bilateral CI users. Results: The results indicated that nine pitch matches are sufficient, which can typically be obtained in approximately 7 min. Conclusion: The results reveal a clinically feasible method for determining pitch matches across the array.

Key Words:

• Cochlear implants
• anatomy & physiology
• instrumentation
• psychoacoustics/hearing science
• bilateral cochlear implants
• pitch matching

Acknowledgements

We thank our participants for the time and effort they put in to this experiment. We thank Advanced Bionics for providing equipment for this study. We also thank Drs Karen Kirk and Ron Chambers for their commentary and feedback. This work was supported by the National Organisation for Hearing Research, NIH/NIDCD, R03-DC-013380, T32DC009975, R01-DC12152, R01-DC001526, R01-DC004993, R03-DC010064.

Declaration of interest

National Organisation for Hearing Research, NIH/NIDCD, R03-DC013380, T32DC009975, R01-DC12152, R01-DC001526, R01-DC004993, R03-DC010064. The data were presented previously as a poster presented at Association for Research in Otolaryngology (2/22/16), San Diego, CA, & Audiology NOW The American Academy of Audiology Conference (4/15/16), Phoenix, AZ.