Effect of reducing electrical stimulation rate on hearing performance of Nucleus^® cochlear implant recipients

Abstract

Objective

To evaluate whether a 500 pulses per second per channel (pps/ch) rate would provide non-inferior hearing performance compared to the 900 pps/ch rate in the Advanced Combination Encoder (ACE™) sound coding strategy.

Design

A repeated measures single-subject design was employed, wherein each subject served as their own control. All except one subject used 900 pps/ch at enrolment. After three weeks of using the alternative rate program, both programs were loaded into the sound processor for two more weeks of take-home use. Subjective performance, preference, words in quiet, sentences in babble, music quality, and fundamental frequency (F0) discrimination were assessed using a balanced design.

Study sample

Data from 18 subjects were analysed, with complete datasets available for 17 subjects.

Results

Non-inferior performance on all clinical measures was shown for the lower rate program. Subjects’ preference ratings were comparable for the programs, with 53% reporting no difference overall. When a preference was expressed, the 900 pps/ch condition was preferred more often.

Conclusion

Reducing the stimulation rate from 900 pps/ch to 500 pps/ch did not compromise the hearing outcomes evaluated in this study. A lower pulse rate in future cochlear implants could reduce power consumption, allowing for smaller batteries and processors.

Keywords:

• Cochlear implant
• stimulation rate
• speech perception
• music quality
• prosody
• SSQ

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This research was funded by The HEARing Cooperative Research Centre, established through the Cooperative Research Centre Program, an Australian Government Initiative.