Associations between illness perceptions, word recognition, and perceived sound quality in cochlear implant users.

OBJECTIVE: Illness perceptions refer to thoughts and ideas an individual has about an illness. The aim was to understand how cochlear implant (CI) users' illness perceptions, in addition to their monosyllabic word recognition abilities, are associated with their self-perceived sound quality. DESIGN: Data were collected during routine CI check-up appointments. Participants completed the Brief Illness Perception Questionnaire (assessing their illness perceptions) and the Hearing Implant Sound Quality Index (assessing their subjective sound quality). Additionally, monosyllabic word recognition abilities were measured with the Freiburg Monosyllable Word Test. Hierarchical regression analysis were utilised to model users' sound quality ratings. Participants' age was entered first as a control variable. In the next step, monosyllabic word recognition was entered. Finally, participants' illness perceptions were entered. STUDY SAMPLE: Fifty-five participants with unilateral CI provision. RESULTS: Monosyllabic word recognition was significant in the second step. When illness perceptions and monosyllabic word recognition were both included in the third step, illness perceptions, but not monosyllabic word recognition, were significant. The model explained 22% of the variance of subjective sound quality. CONCLUSIONS: Monosyllabic word recognition abilities and illness perceptions of CI users are important for their self-reported sound quality, but illness perceptions appear to be potentially more relevant.

Electrically evoked compound action potentials in cochlear implant users with preoperative residual hearing.

Introduction: Residual hearing in cochlear implant (CI) candidates requires the functional integrity of the nerve in particular regions of the cochlea. Nerve activity can be elicited as electrically evoked compound action potentials (ECAP) after cochlear implantation. We hypothesize that ECAP thresholds depend on preoperative residual hearing ability. Materials and methods: In a retrospective study, we analyzed 84 adult cochlear implant users who had received a Nucleus® CI632 Slim Modiolar Electrode and who preoperatively had had residual hearing. Inclusion criteria were severe to profound hearing loss with preoperative measurable hearing in the ear to receive the implant, postlingual hearing loss, German as native language and correct placement of the electrode, inserted completely into the scala tympani. Electrically evoked compound action potential (ECAP) was recorded intraoperatively. The angular insertion was measured for each electrode contact from postoperative computed tomography to estimate the corresponding spiral ganglion frequency. Pure-tone audiometry and allocated ECAP thresholds were tested to investigate possible correlation. Results: The average of hearing thresholds, tested at 0.5, 1, 2, and 4 kHz (4FPTA) was 82 ± 18 (range 47-129) dB HL. The success rate for recording ECAP thresholds was 96.9%. For all comparable pure-tone frequencies (1, 2, 4, and 8 kHz), there was significant correlation between preoperative hearing levels and intraoperative ECAP thresholds (p < 0.001). Higher hearing thresholds are associated with increased ECAP thresholds. Conclusion: In CI candidates with adequate residual hearing, intraoperative electrophysiological measurement records lower thresholds. This outcome may be explained by the neural survival density of the peripheral system, with less neural degeneration.

Association between lateral wall electrode array insertion parameters and audiological outcomes in bilateral cochlear implantation.

PURPOSE: The aims of this study were to compare speech recognition at different postoperative times for both ears in bilaterally implanted patients and to assess the influence of the time of deafness, frequency-to-place mismatch, angular insertion depth (AID) and angular separation between neighbouring electrode contacts on audiometric outcomes. METHODS: This study was performed at an academic tertiary referral centre. A total of 19 adult patients (6 men, 13 women), who received sequential bilateral implantation with lateral wall electrode arrays, were analysed in retrospective. Statistical analysis was performed using two-sided t test, Wilcoxon test, median test, and Spearman's correlation. RESULTS: Postlingually deafened patients (deafness after the age of 10) had a significantly better speech perception (WRS65[CI]) than the perilingually deafened subjects (deafness at the age of 1-10 years) (p < 0.001). Comparison of cochlear duct length between peri- and postlingually deafened subjects showed a slightly significantly smaller cochleae in perilingual patients (p = 0.045). No association between frequency-to-place mismatch as well as angular separation and speech perception could be detected. There was even no significant difference between the both ears in the intraindividual comparison, even if insertion parameters differed. CONCLUSION: The exact electrode position seems to have less influence on the speech comprehension of CI patients than already established parameters as preoperative speech recognition or duration of deafness.

Children with cochlear implant and additional disabilities benefit from consistent device use.

OBJECTIVES: Although the prevalence of additional disabilities (AD) in children with a cochlear implant (CI) is high, children with such disabilities are often excluded from clinical studies, or their specific characteristics are only partially included. The literature shows that several factors need to be considered in evaluating auditory and language development in CI children with AD, including demographic variables as well as the severity and type of disability. Current findings on device use in children show correlations with auditory and language outcome, but little is known about device use specifically in children with AD. The purpose of this study was to determine the auditory and language outcome of CI children with AD and to analyse their datalogging-based daily device use, both 1 year and 2 years after implantation. In addition, any potential correlations between outcome and device use were to be identified. METHODS: A cohort of 32 CI children with 5 different types of AD were included in this retrospective analysis. The children's auditory and language outcome was assessed by the parental questionnaires LittlEARS and ELFRA and by the professional observation tool CAP (Categories of Auditory Performance) 1 and 2 years after implantation. Longitudinal device use was analysed by using the CI system-integrated data-logging; daily duration of CI use, number of coil disconnections and exposure to different listening scenes were recorded. RESULTS: Overall, the cohort's auditory and language performance showed significant progress over time, while reduced abilities became more obvious after 2 years of CI experience. The mean daily duration of CI use increased significantly from 7.8 ± 2.8 to 8.2 ± 2.7 h after 2 years. High numbers of daily coil disconnections were detected, with a significant mean decrease from 83.4 ± 73.1 to 66.3 ± 54.6 whereas the percentage exposure to different listening environments was widely stable over time. Significant rank correlations were identified between outcomes measured by ELFRA and CAP with daily duration of CI use, numbers of coil disconnections and percentage of exposure to speech-characterised listening scenes. CONCLUSION: The auditory and language outcome in CI children with AD is variable, but it progresses over time. Children benefit from a consistent daily device use as well as from a high exposure to speech-characterised environments. Device use should be monitored constantly, with particular focus on daily duration of CI use and, in particular, on the number of coil disconnections if children have a severe motor impairment. Objective data-logging is an important addition to outcome assessment by testing, observations and parental questionnaires. Although assessment in children with AD is a major challenge for professionals, comprehensive assessment is needed to improve cochlear implant services with special adaption to children with AD, and this should include audiological, development-related and psychosocial information. A unified system to classify types of disabilities could help to improve procedures for analysing different outcomes.

Evaluation of a Transimpedance Matrix Algorithm to Detect Anomalous Cochlear Implant Electrode Position.

INTRODUCTION: Transimpedance measurements from cochlear implant electrodes have the potential to identify anomalous electrode array placement, such as tip fold-over (TFO) or fold-back, basal electrode kinking, or buckling. Analysing transimpedance may thus replace intraoperative or post-operative radiological imaging to detect any potential misplacements. A transimpedance algorithm was previously developed to detect deviations from a normal electrode position with the aim of intraoperatively detecting TFO. The algorithm had been calibrated on 35 forced, tip folded electrode arrays in six temporal bones to determine the threshold criterion required to achieve a sensitivity of 100%. Our primary objective here was to estimate the specificity of this TFO algorithm in patients, in a prospective study, for a series of electrode arrays shown to be normally inserted by post-operative imaging. METHODS: Intracochlear voltages were intraoperatively recorded for 157 ears, using Cochlear's Custom Sound™ EP 5 electrophysiological software (Cochlear Ltd., Sydney, NSW, Australia), for both Nucleus® CI512 and CI532 electrode arrays. The algorithm analysed the recorded 22 × 22 transimpedance matrix (TIM) and results were displayed as a heatmap intraoperatively, only visible to the technician in the operating theatre. After all clinical data were collected, the algorithm was evaluated on the bench. The algorithm measures the transimpedance gradients and corresponding phase angles (θ) throughout the TIM and calculates the gradient phase range. If this was greater than the predetermined threshold, the algorithm classified the electrode array insertion as having a TFO. RESULTS: Five ears had no intraoperative TIM and four anomalous matrices were identified from heatmaps and removed from the specificity analysis. Using the 148 remaining data sets (n = 103 CI532 and n = 45 CI512), the algorithm had an average specificity of 98.6% (95.80%-99.75%). CONCLUSION: The algorithm was found to be an effective screening tool for the identification of TFOs. Its specificity was within acceptable levels and resulted in a positive predictive value of 76%, with an estimated incidence of fold-over of 4% in perimodiolar arrays. This would mean 3 out of 4 cases flagged as a fold-over would be correctly identified by the algorithm, with the other being a false positive. The measurements were applied easily in theatre allowing it to be used as a routine clinical tool for confirming correct electrode placement.

Fluctuation in electrical hearing in a Morbus Meniere's patient.

The glycerol test is an easy-to-use instrument to elucidate fluctuations of electrical hearing in patients with Meniere's disease and it might be also used as a therapeutic option.

Age-related language performance and device use in children with very early bilateral cochlear implantation.

OBJECTIVES: Paediatric cochlear implantation within the first year of life results in better outcome in auditory and language skills. Beside individual, audiological and social factors, quantity and quality of daily cochlear implant (CI) use also seem to be an influencing factor. The purpose of this study was to evaluate children's early receptive and expressive language performance considering bilingual language development as well as quantity and quality of daily CI use and intraoperative objective measurements. METHODS: The retrospective analysis included data from 35 very early bilaterally cochlear-implanted children (age at CI M = 8.4 ± 1.5 months). Language performance was assessed by the German standardised test SETK-2 (age at testing M = 29.4 ± 4.0 months). The CI system-integrated data-logging was analysed with regard to daily CoilOn-time, CoilOff and exposure to classified listening scenes. Intraoperatively measured thresholds of evoked compound action potentials (T-ECAPs) were analysed to ensure CI functionality. RESULTS: The cohort showed language performance within the normal range for word comprehension, sentence comprehension and word production, level of sentence production was reduced. Overall, bilingual children performed less well than monolingual children. Intraoperative T-ECAPs were recorded for the total cohort and no anomalies were detected. Children used their CI for about 8.7 ± 1.4 h per day, most of this time spent in a quiet environment (38%). Word production was significantly correlated with the daily duration of CI use (CoilOn-time) and with exposure to the listening environment Speech. No correlation was found between number of daily coil disconnections (CoilOff) and language performance. CONCLUSION: Very early bilateral cochlear implantation may result in age-appropriate language skills already at the age of 2 years. Monolingualism seems to a better condition for early language development with CI than bilingualism. Especially for word production, the daily duration of CI use and exposure time in a speech-characterised environment seem to be additional positive factors. Monitoring the data-logs should be one important focus of professionals during the postoperative rehabilitation process to detect potential benefits and risks. These findings should be integrated into rehabilitative therapy and parent counselling.

Electrode Translocations in Perimodiolar Cochlear Implant Electrodes: Audiological and Electrophysiological Outcome.

INTRODUCTION: Despite using the soft-surgery technique, cochlear implantation may increase the damage of the intracochlear structures due to a scalar translocation of the electrode. The aim of this work was to investigate the incidence as well as the audiological and electrophysiological outcome for electrode translocations and complete scala tympani insertions of perimodiolar electrodes within a large group of patients. MATERIAL AND METHODS: The investigations were performed retrospectively on 255 adult subjects with a Nucleus Contour Advance or Slim Modiolar electrode (Cochlear Ltd.). The scalar position was assessed by postoperative rotational tomography. Intraoperative and one year after CI activation measured ECAP thresholds were examined as well as the postoperative speech recognition in quiet using the Freiburg monosyllable word test. RESULTS: The incidence of a translocation was significantly lower with the Slim Modiolar than with the Contour Advance electrode (5.1% versus 32.3%; p<0.05). With a scala tympani placement the median speech recognition score was 75% (range: 20- 100%) with the Contour Advance and 72.5% (range: 27.5-95%) with the Slim Modiolar electrode. In cases with an electrode translocation, speech recognition scores show a median of 75% (range: 45-100%) and 73.8% (range: 40-80%), respectively. No significant differences in speech recognition were found between translocations and scala tympani insertions with both electrodes. Compared to scala tympani insertions, electrode translocations yielded higher ECAP thresholds at apical and medial electrode contacts (p<0.05). CONCLUSION: The incidence of an electrode translocation is determined for both perimodiolar electrode types analyzed in this work. ECAP measurements provide additional information for detecting translocations compared to radiological imaging. However, the postoperative speech recognition in quiet was not affected by the scalar position in the electrodes examined here.

Outcomes for a clinically representative cohort of hearing-impaired adults using the Nucleus® CI532 cochlear implant.

PURPOSE: Hearing performance data was collected from a large heterogeneous group of subjects implanted with the Cochlear™ Nucleus® CI532 with Slim Modiolar Electrode, for the purposes of postmarket clinical follow-up. Data was analysed for factors which may predict postoperative speech recognition scores. METHODS: Data was collected retrospectively from five German clinics for 159 subjects from March 2017 to August 2018. Hearing thresholds and recognition scores for monosyllabic words in quiet and sentences in noise were measured preoperatively and at 3 and 6 months postoperatively. RESULTS: There was a mean gain of 44% points (95% CI 39-49%) at 6 months in monosyllable scores in quiet for implanted ears. Preoperative hearing thresholds in implant ears increased systematically with decreasing age; however, younger subjects had better baseline monosyllable scores with hearing aids compared with older subjects. Baseline performance alone explained 14% of the variation in postoperative scores. Residual hearing was preserved on average to within 22 dB at 250 Hz and 30 dB at 500 Hz of preoperative levels. CONCLUSIONS: In a large and varied cohort of routinely treated hearing-impaired adults, speech recognition with the CI532 for German monosyllabic words in quiet at 6 months was equivalent to performance reported at one year or more in other published studies. Although younger subjects had poorer preoperative pure-tone thresholds, they had better preoperative word recognition scores compared with older subjects, and also had higher post implant scores. Further research is required to identify if this phenomenon is just applicable to German health system assessment and referral practices.

Cortical auditory evoked potentials in cochlear implant listeners via single electrode stimulation in relation to speech perception.

The objectives of this study were to investigate the effects of place of stimulation on cortical auditory evoked potentials in relation to speech performance in cochlear implant listeners. It was designed that cortical responses were recorded for single-electrode bursts at apical, medial and basal portions of the electrode array with varying inter-stimulus intervals ranging from 300 ms to 5 s. Latency and amplitude of N1 and P2 peaks were analysed in relation to monosyllabic word scores. The study sample was 44 adult cochlear implant users ranging in age from 28 to 86 years. N1, P2 and N1-P2 amplitudes declined significantly from apical to basal electrodes. The most robust and pronounced responses were recorded for slower stimulation rates (5 s). Speech recognition correlated positively with N1 and N1-P2 amplitudes at the medial electrode. P2 latency showed a significant negative correlation with speech performance at the apical electrode. At last, cortical responses varied significantly depending on the stimulation site and rate. We can objectively quantify speech performance with the N1, N1-P2 amplitude and P2 latency in cochlear implant users. Deafness-related neural degeneration persists even after the cochlear implantation and is more distinct at the base than the apex of the cochlea.

Speech Perception of Elderly Cochlear Implant Users Under Different Noise Conditions.

OBJECTIVE: The primary objective of this study was the comparison of younger and older (>75 yr) CI recipients' performance for speech perception in quiet and in competing continuous and fluctuating noise. STUDY DESIGN: Prospective, comparative clinical study. SETTING: University hospital. PATIENTS: Fifty patients, 25 older and 25 younger than 75 years, with a postlingually acquired profound hearing loss who received a cochlear implant at least 1 year before study start were enrolled. INTERVENTIONS: Cochlear implantation. MAIN OUTCOME MEASURES: We measured speech perception using monosyllable (Freiburg monosyllables) and sentence materials (Göttingen sentences) in quiet. In addition, speech perception for sentences was measured under two different noise conditions: with a continuous, speech-simulating noise signal (CCITT noise) and the FASTL noise (fluctuating noise). RESULTS: We did not find a significant difference between the performance for younger and the older cohort on speech perception tasks in quiet for Freiburg monosyllables (63.4% ±â€Š20% and 61.7% ±â€Š18.1%, respectively) and for the Göttingen sentences in quiet (73.5% ±â€Š24.3% and 75% ±â€Š25%, respectively). No significant difference was observed for performance between the two age groups when listening in continuous CCITT noise (18.9% ±â€Š24.0% and 29.5% ±â€Š25.2% perception score respectively) or in FASTL noise (27.8% ±â€Š24.2% and 34.4% ±â€Š27.8% perception score, respectively). CONCLUSION: There is no supporting evidence from our evaluations of word and sentence perception in quiet and noise that elderly CI users older than 75 years of age perform more poorly than those younger than 75 years of age.