Effect of signal processing strategy and stimulation type on speech and auditory perception in adult cochlear implant users

Abstract

Objective: The objective of this study was to investigate the effects of signal processing strategy on speech understanding and auditory function for adult cochlear implant (CI) users with a focus on the effects of sequential versus paired stimulation.Design: Within-subjects, repeated measures design was utilised to compare performance between processing strategies and stimulation type on various measures of auditory function and subjective sound quality. Testing with subsequent strategies was completed after a total familiarisation time of two weeks. Study Sample:Ten post-lingually deafened adult CI users were recruited from a clinical population. Participants had a minimum of 13 months CI experience. Ages ranged from 25-78 years. All participants had long-term experience with the optima strategy; eight with sequential stimulation and two with paired stimulation. Results:We found no statistically significant effect of processing strategy. We observed an effect of stimulation type with sequential stimulation yielding significantly higher performance than paired stimulation for speech understanding in quiet and in noise, and subjective estimates of sound quality. No significant differences were noted across strategy or stimulation for music perception, spectral resolution or temporal resolution. Conclusions:Many patients utilise paired stimulation -the default stimulation type in the clinical software; however, sequential stimulation yielded significantly higher outcomes on multiple measures.

The Effects of Paired versus Sequential Stimulation on Speech Recognition Outcomes of Adult Cochlear Implant Recipients

“…Given these results, CI clinicians should consider programming their new and established AB CI patients with Optima-S to maximize their overall speech performance with little to no risk to the patient. Our results, in accordance with other researchers [Buechner et al, 2005;Reynolds and Gifford, 2019], show that an S strategy is superior to a P strategy for speech understanding in noise. In theory, an S strategy reduces the chance for channel interaction due to the differences in rate of stimulation between paired and sequential stimulation, which can result in improved speech recognition.…”

“…Buechner et al [2005] found that subjects with HiRes S performed significantly better than those with HiRes P for sentence recognition in noise and word recognition, yet results were negligible between the two strategies for sentences in quiet. Conversely, Dunn et al [2006] found no significant group differences for sentence perception in noise across P and S strategies when comparing speech perception outcomes of 7 adult AB CI users; however, individual results were better for HiRes P. Recently, Reynolds and Gifford [2019] evaluated speech perception outcomes of 10 subjects across the 6 AB strategies previously discussed, and results suggested subjective preference and overall significantly higher speech scores for words in quiet and sentences in noise using an S stimulation. Their study did not find significant differences between any of the S strategies (HiRes S, HiRes S 120, and Optima).…”

“…Cochlear implantation is a proven-effective treatment for adults with moderate to profound sensorineural hearing loss. While many variables influence patient performance with a cochlear implant (CI), appropriate device programming [Shapiro and Bradham, 2012] and selection of the appropriate sound-processing strategy are important factors in optimizing overall speech perception Audiol Neurotol 2021;26:188-194 DOI: 10.1159/000511449 outcomes [Koch et al, 2004;Buechner et al, 2005;Dunn et al, 2006;Firszt et al, 2009;Melo et al, 2012;Reynolds and Gifford, 2019].…”

“…Past research on speech recognition performance differences between an S strategy and a P strategy for adult AB CI users has produced variable results and has been limited by small sample sizes -the largest with only 13 subjects [Buechner et al, 2005;Dunn et al, 2006;Reynolds and Gifford, 2019]. Buechner et al [2005] found that subjects with HiRes S performed significantly better than those with HiRes P for sentence recognition in noise and word recognition, yet results were negligible between the two strategies for sentences in quiet.…”

Musical Emotion Perception in Bimodal Patients: Relative Weighting of Musical Mode and Tempo Cues

“…Music perception ability in CI users is most commonly quantified in terms of four key structural features of music: rhythm, pitch, melody, and timbre. For adult CI patients, performance on temporal-based music tasks tends to be normal or near normal, suggesting minimal to no deficit in tempo or rhythm discrimination (Gfeller et al, 1997;Hsiao and Gfeller, 2012;Kong et al, 2004;Reynolds and Gifford, 2019). In contrast, for the reasons discussed above, pitch, melody, and timbre perception are significantly poorer (Drennan et al, 2015;Kang et al, 2009).…”