Poor Performer: A Distinct Entity in Cochlear Implant Users?

INTRODUCTION: Several factors are known to influence speech perception in cochlear implant (CI) users. To date, the underlying mechanisms have not yet been fully clarified. Although many CI users achieve a high level of speech perception, a small percentage of patients does not or only slightly benefit from the CI (poor performer, PP). In a previous study, PP showed significantly poorer results on nonauditory-based cognitive and linguistic tests than CI users with a very high level of speech understanding (star performer, SP). We now investigate if PP also differs from the CI user with an average performance (average performer, AP) in cognitive and linguistic performance. METHODS: Seventeen adult postlingually deafened CI users with speech perception scores in quiet of 55 (9.32) % (AP) on the German Freiburg monosyllabic speech test at 65 dB underwent neurocognitive (attention, working memory, short- and long-term memory, verbal fluency, inhibition) and linguistic testing (word retrieval, lexical decision, phonological input lexicon). The results were compared to the performance of 15 PP (speech perception score of 15 [11.80] %) and 19 SP (speech perception score of 80 [4.85] %). For statistical analysis, U-Test and discrimination analysis have been done. RESULTS: Significant differences between PP and AP were observed on linguistic tests, in Rapid Automatized Naming (RAN: p = 0.0026), lexical decision (LexDec: p = 0.026), phonological input lexicon (LEMO: p = 0.0085), and understanding of incomplete words (TRT: p = 0.0024). AP also had significantly better neurocognitive results than PP in the domains of attention (M3: p = 0.009) and working memory (OSPAN: p = 0.041; RST: p = 0.015) but not in delayed recall (delayed recall: p = 0.22), verbal fluency (verbal fluency: p = 0.084), and inhibition (Flanker: p = 0.35). In contrast, no differences were found hereby between AP and SP. Based on the TRT and the RAN, AP and PP could be separated in 100%. DISCUSSION: The results indicate that PP constitute a distinct entity of CI users that differs even in nonauditory abilities from CI users with an average speech perception, especially with regard to rapid word retrieval either due to reduced phonological abilities or limited storage. Further studies should investigate if improved word retrieval by increased phonological and semantic training results in better speech perception in these CI users.

Nonverbal synchrony in subjects with hearing impairment and their significant others.

Introduction: Hearing loss has a great impact on the people affected, their close partner and the interaction between both, as oral communication is restricted. Nonverbal communication, which expresses emotions and includes implicit information on interpersonal relationship, has rarely been studied in people with hearing impairment (PHI). In psychological settings, non-verbal synchrony of body movements in dyads is a reliable method to study interpersonal relationship. Material and methods: A 10-min social interaction was videorecorded in 39 PHI (29 spouses and 10 parent-child dyads) and their significant others (SOs). Nonverbal synchrony, which means the nonverbal behaviors of two interacting persons (referring to both general synchrony and the role of leading) and verbal interaction (percentage of speech, frequency of repetitions, and queries) were analyzed by computer algorithms and observer ratings. Hearing-related quality of life, coping mechanisms, general psychopathology, quality of relationship, and burden of hearing loss experienced by SOs were assessed using questionnaires. Results: In the 39 dyads, true nonverbal synchrony differed from pseudosynchrony [t (43.4) = 2.41; p = 0.02] with a medium effect size (d = 0.42). Gender of PHI had a significant effect on general synchrony (p = 0.025) and on leading by SOs (p = 0.017). Age gap correlated with synchronic movements (p = 0.047). Very short duration of hearing impairment was associated with lower nonverbal synchrony in the role of leading by SOs (p = 0.031). Feeling of closeness by PHI correlated negatively with the role of leading by SOs (p > 0.001) and feeling of closeness by SOs was positively associated with leading by PHI (p = 0.015). No correlation was detected between nonverbal synchrony and other questionnaires. Burden experienced by the SOs was higher in SOs who reported less closeness (p = 0.014). Discussion: A longer hearing impairment leads to more nonverbal leading by SOs compared to PHI with very short duration of hearing loss, possibly because of the long-lasting imbalance in communication. If PHI felt more closeness, SOs led less and vice versa. Burden experienced by SOs negatively correlated with closeness reported by SOs. Use of nonverbal signals and communication might help to improve benefits of auditory rehabilitation for PHI and decrease burden experienced by SOs.

Nonauditory Functions in Low-performing Adult Cochlear Implant Users.

INTRODUCTION: Despite substantial benefits of cochlear implantation (CI) there is a high variability in speech recognition, the reasons for which are not fully understood. Especially the group of low-performing CI users is under-researched. Because of limited perceptual quality, top-down mechanisms play an important role in decoding the speech signal transmitted by the CI. Thereby, differences in cognitive functioning and linguistic skills may explain speech outcome in these CI subjects. MATERIAL AND METHODS: Fifteen post-lingually deaf CI recipients with a maximum speech perception of 30% in the Freiburger monosyllabic test (low performer = LP) underwent visually presented neurocognitive and linguistic test batteries assessing attention, memory, inhibition, working memory, lexical access, phonological input as well as automatic naming. Nineteen high performer (HP) with a speech perception of more than 70% were included as a control. Pairwise comparison of the two extreme groups and discrimination analysis were carried out. RESULTS: Significant differences were found between LP and HP in phonological input lexicon and word retrieval (p = 0.0039∗∗). HP were faster in lexical access (p = 0.017∗) and distinguished more reliably between non-existing and existing words (p = 0.0021∗∗). Furthermore, HP outperformed LP in neurocognitive subtests, most prominently in attention (p = 0.003∗∗). LP and HP were primarily discriminated by linguistic performance and to a smaller extent by cognitive functioning (canonic r = 0.68, p = 0.0075). Poor rapid automatic naming of numbers helped to discriminate LP from HP CI users 91.7% of the time. CONCLUSION: Severe phonologically based deficits in fast automatic speech processing contribute significantly to distinguish LP from HP CI users. Cognitive functions might partially help to overcome these difficulties.