High-Variability Sentence Recognition in Long-Term Cochlear Implant Users

Abstract

Objective:The objective of the present study was to determine whether long-term cochlear implant (CI) users would show greater variability in rapid phonological coding skills and greater reliance on slow-effortful compensatory executive functioning (EF) skills than normal hearing (NH) peers on perceptually challenging high-variability sentence recognition tasks. We tested the following three hypotheses: First, CI users would show lower scores on sentence recognition tests involving high speaker and dialect variability than NH controls, even after adjusting for poorer sentence recognition performance by CI users on a conventional low-variability sentence recognition test. Second, variability in fast-automatic rapid phonological coding skills would be more strongly associated with performance on high-variability sentence recognition tasks for CI users than NH peers. Third, compensatory EF strategies would be more strongly associated with performance on high-variability sentence recognition tasks for CI users than NH peers.Design: Two groups of children, adolescents, and young adults aged 9 to 29 years participated in this cross-sectional study: 49 long-term CI users (≥ 7 years) and 56 NH controls. All participants were tested on measures of rapid phonological coding (Children's Test of Nonword Repetition), conventional sentence recognition (Harvard Sentence Recognition Test), and two novel highvariability sentence recognition tests that varied the indexical attributes of speech [Perceptually Robust English Sentence Test Open-set test (PRESTO) and PRESTO Foreign-Accented English test]. Measures of EF included verbal working memory (WM), spatial WM, controlled cognitive fluency, and inhibition-concentration.Results: CI users scored lower than NH peers on both tests of high-variability sentence recognition even after conventional sentence recognition skills were statistically controlled. Correlations between rapid phonological coding and high-variability sentence recognition scores were stronger for the CI sample than for the NH sample even after basic sentence perception skills were statistically controlled. Scatterplots revealed different ranges and slopes for the relationship

Serial Recall Predicts Vocoded Sentence Recognition Across Spectral Resolutions

“…Additionally, the range of individual variability in sensory impairment differs across listeners with hearing loss and listeners with normal hearing. As a result, listeners with hearing loss often show greater variability in their speech recognition outcomes than listeners with normal hearing (see G. N. Smith et al, 2019, as a recent example). A group with a wider range of performance will have apparently stronger correlations than a group with a narrower range.…”

“…This relationship is most evident in listeners with hearing loss, who often struggle with speech recognition even if they use hearing aids or cochlear implants. Listeners with hearing loss often differ from listeners with typical hearing in their relationships between speech recognition and various measures of cognition, such as fluid intelligence, memory, and attention (Kaandorp et al, 2017;Kronenberger et al, 2014;Moberly et al, 2016;Moberly, Houston, et al, 2017;O'Neill et al, 2019;G. N. Smith et al, 2019).…”

Assessing Higher Order Language Processing in Long-Term Cochlear Implant Users

“…For children with CIs, it is likely that both informationprocessing channels contribute to spoken language processing to a greater degree than they do in NH peers. CI users show greater variability than NH peers in fast, automatic processing, because of large individual differences in the quality of phonological and lexical representations of language in long-term memory (LTM) in CI users (Smith, Pisoni, & Kronenberger, 2019). This variability in fast, automatic processing in CI users is related to speech recognition and sentence repetition skills (Smith et al, 2019).…”

“…CI users show greater variability than NH peers in fast, automatic processing, because of large individual differences in the quality of phonological and lexical representations of language in long-term memory (LTM) in CI users (Smith, Pisoni, & Kronenberger, 2019). This variability in fast, automatic processing in CI users is related to speech recognition and sentence repetition skills (Smith et al, 2019). In addition, the slow, effortful channel involving compensatory executive functioning skills such as verbal working memory (WM) is likely to be more heavily used by CI users than NH peers under challenging speech recognition and spoken language processing conditions because of the increased demands of such tasks on limited cognitive resources for CI users (Kronenberger, Henning, Ditmars, & Pisoni, 2018).…”

“…In addition, the slow, effortful channel involving compensatory executive functioning skills such as verbal working memory (WM) is likely to be more heavily used by CI users than NH peers under challenging speech recognition and spoken language processing conditions because of the increased demands of such tasks on limited cognitive resources for CI users (Kronenberger, Henning, Ditmars, & Pisoni, 2018). Consequently, CI users engage slow, effortful, conscious processing mechanisms much more often than NH peers to compensate for poorer fast, automatic processing of language (Smith et al, 2019).…”