Forward Digit Span and Word Familiarity Do Not Correlate With Differences in Speech Recognition in Individuals With Cochlear Implants After Accounting for Auditory Resolution

Abstract

Purpose In individuals with cochlear implants, speech recognition is not associated with tests of working memory that primarily reflect storage, such as forward digit span. In contrast, our previous work found that vocoded speech recognition in individuals with normal hearing was correlated with performance on a forward digit span task. A possible explanation for this difference across groups is that variability in auditory resolution across individuals with cochlear implants could conceal the true relationship between speech and memory tasks. Here, our goal was to determine if performance on forward digit span and speech recognition tasks are correlated in individuals with cochlear implants after controlling for individual differences in auditory resolution. Method We measured sentence recognition ability in 20 individuals with cochlear implants with Perceptually Robust English Sentence Test Open-set sentences. Spectral and temporal modulation detection tasks were used to assess individual differences in auditory resolution, auditory forward digit span was used to assess working memory storage, and self-reported word familiarity was used to assess vocabulary. Results Individual differences in speech recognition were predicted by spectral and temporal resolution. A correlation was found between forward digit span and speech recognition, but this correlation was not significant after controlling for spectral and temporal resolution. No relationship was found between word familiarity and speech recognition. Forward digit span performance was not associated with individual differences in auditory resolution. Conclusions Our findings support the idea that sentence recognition in individuals with cochlear implants is primarily limited by individual differences in working memory processing, not storage. Studies examining the relationship between speech and memory should control for individual differences in auditory resolution.

Exploring neurocognitive factors and brain activation in adult cochlear implant recipients associated with speech perception outcomes—A scoping review

“…Similar tasks are used to measure working memory capacity with auditory stimuli instead of visual stimuli ( Table 8 ). The digit span task is used in four of the included studies (r = –0.27, p = 0.35) ( Holden et al, 2013 ; Moberly et al, 2017a ; Bosen et al, 2021 ; Luo et al, 2022 ). Scores on these tasks were not significantly correlated to words nor sentences in quiet and noise when administered preimplantation (measured once) or postimplantation ( Holden et al, 2013 ; Moberly et al, 2017b ).…”

“…, by reporting the degree of familiarity with words (Pisoni et al, 2018;Skidmore et al, 2020;Bosen et al, 2021;, or describing the similarity or difference between two words (Holden et al, 2013) (see Table 11 for an overview). In three out of ten papers there was an indication of…”

Subjective cognitive decline is associated with a higher risk of objective cognitive decline: A cross-sectional and longitudinal study

“…The Mini- mental State Examination (MMSE) ( 19 ) and Montreal Cognitive Assessment (MoCA) ( 20 ) were used to assess the subjects' overall cognitive function, while Digit Span ( 21 ), Auditory Verbal Learning Test (AVLT) ( 22 ), Associative Learning Test (ALT) ( 23 ), Verbal Fluency (VF) ( 24 ), Wechsler's filling and Wechsler's building blocks ( 25 ) were used to assess their working memory storage (digit span) ( 26 ), episodic verbal memory (AVLT) ( 27 ), associative learning (ALT) ( 28 ), language, memory and executive functioning (VF) ( 29 ), and executive functioning (Wechsler's filling and Wechsler's building blocks), respectively. In cohort 1, the scales used included MMSE and MoCA, while study 2 included all of the neuropsychological tests mentioned above.…”

Factors Affecting the Use of Speech Testing in Adult Audiology

“…They are commonly used as an outcome measure in auditory research studies e.g. investigating benefits of hearing devices ( Bosen et al, 2021 ; Ricketts & Picou, 2021 ) or effects of auditory training ( Burk et al, 2006 ; Zhang et al, 2021 ) and prior to hearing aid fitting to capture a listener’s functional ability and identify appropriate intervention strategies ( Ricketts et al, 2019 ). Assessing speech perception abilities in the presence of noise may better reflect the listening conditions that patients report as more challenging ( Carhart & Tillman, 1970 ; Smits & Houtgast, 2005 ).…”