Measurement of Spectro-Temporal Processing by Cochlear Implant Users: Effects of Stimulus Level and Validation of an...

Evaluating adjustments to cochlear implant (CI) settings is challenging as recipients need time to adapt for optimal speech test performance. The Spectro-Temporal Ripple for Investigating Processor EffectivenesS (STRIPES) test, a language-independent measure of spectro-temporal resolution, has been validated with Advanced Bionics and Cochlear CI systems. This study investigates if performance on the STRIPES test varies with presentation level in a loudspeaker setup and its relationship with outcomes on the British Coordinate Response Measure (CRM) test. In addition, it extends the use of STRIPES and its online version "webSTRIPES" to Med-El CI systems.

A prospective, single-blind, two-session repeated-measures study was conducted with 10 CI users. The first session included three blocks: pre-test webSTRIPES, STRIPES at three loudspeaker presentation levels (50, 65, and 75 dB SPL), and post-test webSTRIPES. The second session measured the speech reception threshold (SRT70) for CRM sentences with a time-reversed speech masker, presented at the same three levels.

Presentation level did not significantly affect STRIPES ripple density thresholds or SRT70 for CRM sentences. A significant correlation was found between STRIPES loudspeaker and webSTRIPES thresholds. WebSTRIPES showed good-to-excellent test-retest reliability. The correlation between CRM SRT70 and STRIPES thresholds, while in the predicted direction, was not statistically significant, likely due to the small sample size (n = 7), which may have limited the power to detect a meaningful relationship.

STRIPES and webSTRIPES ripple density threshold scores can be reliably measured with Med-El CI systems, unaffected by presentation level. The STRIPES test is a promising tool for assessing adult CI listener outcomes without requiring prolonged acclimatization to programming changes.