Lexical-Access Ability and Cognitive Predictors of Speech Recognition in Noise in Adult Cochlear Implant Users

Abstract

Not all of the variance in speech-recognition performance of cochlear implant (CI) users can be explained by biographic and auditory factors. In normal-hearing listeners, linguistic and cognitive factors determine most of speech-in-noise performance. The current study explored specifically the influence of visually measured lexical-access ability compared with other cognitive factors on speech recognition of 24 postlingually deafened CI users. Speech-recognition performance was measured with monosyllables in quiet (consonant-vowel-consonant [CVC]), sentences-in-noise (SIN), and digit-triplets in noise (DIN). In addition to a composite variable of lexical-access ability (LA), measured with a lexical-decision test (LDT) and word-naming task, vocabulary size, working-memory capacity (Reading Span test [RSpan]), and a visual analogue of the SIN test (text reception threshold test) were measured. The DIN test was used to correct for auditory factors in SIN thresholds by taking the difference between SIN and DIN: SRTdiff. Correlation analyses revealed that duration of hearing loss (dHL) was related to SIN thresholds. Better working-memory capacity was related to SIN and SRTdiff scores. LDT reaction time was positively correlated with SRTdiff scores. No significant relationships were found for CVC or DIN scores with the predictor variables. Regression analyses showed that together with dHL, RSpan explained 55% of the variance in SIN thresholds. When controlling for auditory performance, LA, LDT, and RSpan separately explained, together with dHL, respectively 37%, 36%, and 46% of the variance in SRTdiff outcome. The results suggest that poor verbal working-memory capacity and to a lesser extent poor lexical-access ability limit speech-recognition ability in listeners with a CI.

Serial Recall Predicts Vocoded Sentence Recognition Across Spectral Resolutions

“…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, Harris, et al, 2017 ; Moberly et al, 2016 ; Moberly, Houston, et al, 2017 ; O'Neill et al, 2019 ; G. N. Smith et al, 2019 ). Currently, it is unclear how to interpret these differences across groups of listeners.…”

Correlation between Speech Perception Outcomes after Cochlear Implantation and Postoperative Acoustic and Electric Hearing Thresholds

“…The duration of deafness, etiology of hearing loss, and preoperative speech understanding are known to influence postoperative speech perception outcomes [ 1 , 2 , 3 , 4 , 5 , 6 ]. However, the results for cognitive factors [ 7 , 8 ] and age at implantation in adult CI users [ 1 , 2 , 9 , 10 ] have been inconclusive. Nevertheless, even the above-mentioned variables show only limited abilities to explain or predict large variabilities in CI speech recognition outcomes.…”

FreeHear: A New Sound-Field Speech-in-Babble Hearing Assessment Tool

“…Other studies have used a free-field DIN to study performance of severe to profoundly hearing impaired users of cochlear implants (de Graaff et al., 2018; Kaandorp et al., 2017). These studies have focused on comparisons between different speech-in-noise testing, but they have validated the reliability of free-field delivery of the DIN.…”

“…These tasks have the obvious merit of providing an assessment with the face validity of speech perception but may lack standardization and, therefore, clinical utility. Word and sentence stimuli also rest heavily on higher order cognitive processing, particularly in the language, attention, and memory domains (Kaandorp, Smits, Merkus, Festen, & Goverts, 2017; Nuesse, Steenken, Neher, & Holube, 2018). Because they involve speech stimuli, they also need to be adapted to and normalized for different languages, an arduous and imprecise process.…”