The impact of cochlear implant microphone settings on the binaural hearing of experienced cochlear implant users with single-sided deafness

Abstract

Objective Cochlear implantation has become a well-accepted treatment option for people with single-sided deafness (SSD) and has become a clinical standard in many countries. A cochlear implant (CI) is the only device which restores binaural hearing. The effect of microphone directionality (MD) settings has been investigated in other CI indication groups, but its impact on speech perception in noise has not been established in CI users with SSD. The focus of this investigation was, therefore, to assess binaural hearing effects using different MD settings in CI users with SSD. Methods Twenty-nine experienced CI users with SSD were recruited to determine speech reception thresholds with varying target and noise sources to define binaural effects (head shadow, squelch, summation, and spatial release from masking), sound localization, and sound quality using the SSQ12 and HISQUI19 questionnaires. Outcome measures included the MD settings “natural”, “adaptive”, and “omnidirectional”. Results The 29 participants involved in the study were divided into two groups: 11 SONNET users and 18 OPUS 2/RONDO users. In both groups, a significant head shadow effect of 7.4–9.2 dB was achieved with the CI. The MD setting “adaptive” provided a significant head shadow effect of 9.2 dB, a squelch effect of 0.9 dB, and spatial release from masking of 7.6 dB in the SONNET group. No significant summation effect could be determined in either group with CI. Outcomes with the omnidirectional setting were not significantly different between groups. For both groups, localization improved significantly when the CI was activated and was best when the omnidirectional setting was used. The groups’ sound quality scores did not significantly differ. Conclusions Adaptive directional microphone settings improve speech perception and binaural hearing abilities in CI users with SSD. Binaural effect measures are valuable to quantify the benefit of CI use, especially in this indication group.

Sound Source Localization by Cochlear Implant Recipients with Normal Hearing in the Contralateral Ear: Effects of Spectral Content and Duration of Listening Experience

“…Also, the present report did not control the microphone settings used for the familiar maps, which may influence localization. Better performance has been reported for CI users with the omnidirectional configuration as compared to adaptive [Kurz et al, 2021]. Interestingly, the one listener (Listener 9) who demonstrated poorer performance at the later visit had been listening with an adaptive directionality.…”

Long‐Term Improvement in Localization for Cochlear Implant Users with Single‐Sided Deafness

“…Additionally, participants were evaluated with their preferred microphone settings. The directional microphone settings (e.g., adaptive) may have influenced the observed findings, though better localization has been reported with an omnidirectional setting over the adaptive setting 27 . It is also unclear if the improvement seen in variable error is secondary to improved confidence in responses or perhaps increased familiarity with the task; however, task familiarity seems unlikely given that the majority of participants did not present at the 4‐year visit, so they had a 2‐year gap between visits.…”

“…The directional microphone settings (e.g., adaptive) may have influenced the observed findings, though better localization has been reported with an omnidirectional setting over the adaptive setting. 27 It is also unclear if the improvement seen in variable error is secondary to improved confidence in responses or perhaps increased familiarity with the task; however, task familiarity seems unlikely given that the majority of participants did not present at the 4-year visit, so they had a 2-year gap between visits. Regarding error measures, corrections for multiple tests were not performed to address the possibility for elevated type 1 error, though trends were supported by individual response plots.…”

Cochlear Implantation Outcomes in Adults With Single-Sided Deafness: A Systematic Review and Meta-analysis

“…Twenty-five studies reported speech recognition in noise outcomes. Performance was evaluated with a two-speaker setup in a sound booth in different target-to-masker configurations (colocated versus spatially separated) (20,21,23,24,(26)(27)(28)(29)(30)(31)(32)(33)37,38,(40)(41)(42)44,46,47,49,50,52,55,56). Performance was evaluated with the speech presented from the front (S0) or toward the CI-ear (Sci) and the masking noise either from the front (N0), toward the CI-ear (Nci), or toward the normal hearing ear (Nnh).…”