Changes in visually and auditory attended audiovisual speech processing in cochlear implant users: A longitudinal ERP study.

Limited auditory input, whether caused by hearing loss or by electrical stimulation through a cochlear implant (CI), can be compensated by the remaining senses. Specifically for CI users, previous studies reported not only improved visual skills, but also altered cortical processing of unisensory visual and auditory stimuli. However, in multisensory scenarios, it is still unclear how auditory deprivation (before implantation) and electrical hearing experience (after implantation) affect cortical audiovisual speech processing. Here, we present a prospective longitudinal electroencephalography (EEG) study which systematically examined the deprivation- and CI-induced alterations of cortical processing of audiovisual words by comparing event-related potentials (ERPs) in postlingually deafened CI users before and after implantation (five weeks and six months of CI use). A group of matched normal-hearing (NH) listeners served as controls. The participants performed a word-identification task with congruent and incongruent audiovisual words, focusing their attention on either the visual (lip movement) or the auditory speech signal. This allowed us to study the (top-down) attention effect on the (bottom-up) sensory cortical processing of audiovisual speech. When compared to the NH listeners, the CI candidates (before implantation) and the CI users (after implantation) exhibited enhanced lipreading abilities and an altered cortical response at the N1 latency range (90-150 ms) that was characterized by a decreased theta oscillation power (4-8 Hz) and a smaller amplitude in the auditory cortex. After implantation, however, the auditory-cortex response gradually increased and developed a stronger intra-modal connectivity. Nevertheless, task efficiency and activation in the visual cortex was significantly modulated in both groups by focusing attention on the visual as compared to the auditory speech signal, with the NH listeners additionally showing an attention-dependent decrease in beta oscillation power (13-30 Hz). In sum, these results suggest remarkable deprivation effects on audiovisual speech processing in the auditory cortex, which partially reverse after implantation. Although even experienced CI users still show distinct audiovisual speech processing compared to NH listeners, pronounced effects of (top-down) direction of attention on (bottom-up) audiovisual processing can be observed in both groups. However, NH listeners but not CI users appear to show enhanced allocation of cognitive resources in visually as compared to auditory attended audiovisual speech conditions, which supports our behavioural observations of poorer lipreading abilities and reduced visual influence on audition in NH listeners as compared to CI users.

Adaptation of the Cochlear Implant Quality of Life-35 Profile Into German.

PURPOSE: The adaptation of existing questionnaires is a valuable method to make instruments available in multiple languages. It is necessary to assure the quality of an adaptation by following adaptation guidelines. The Cochlear Implant Quality of Life-35 Profile (CIQOL-35 Profile) was developed and validated to measure the functional abilities in English-speaking adult CI users but is not yet available in German. In this study, we performed a cross-cultural adaptation of this instrument to make it applicable in research and rehabilitation with German-speaking patients. METHOD: This study followed established practice guidelines for translating and adapting hearing-related questionnaires. Professional translators and health care professionals with experience with patients with hearing loss translated all items forward and backward multiple times. A committee reviewed the process and decided when a satisfactory consensus was achieved. Next, we examined the intelligibility of the German version using cognitive interviews with 15 adult CI users. RESULTS: For most items, there was no difficulty with direct translation. In items that turned out to be more difficult to translate, it proved to be very helpful to compare the back translation to the original version, discuss the wording in the committee, and ask the source-language questionnaire developer. During the interviews, issues of comprehension for some phrases were identified. These phrases were changed according to the participant's questions and suggestions. CONCLUSIONS: The CIQOL-35 Profile was successfully adapted into German. The German version of the questionnaire is now available for research and clinical practice. Further validation of the German CIQOL-35 Profile is in progress. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.25386571.

Cochlear measurement in computed tomography and magnetic resonance imaging data sets by the Otoplan measurement tool: a retrospective comparative study.

BACKGROUND: Using Otoplan software, it is possible to measure the cochlea before cochlear implant surgery. Until now, computed tomography (CT) of the cochlea has been necessary for this purpose. The aim of this study was to find out whether measuring the cochlea with magnetic resonance imaging (MRI) using Otoplan is possible with the same accuracy. METHODS: The cochlea of 44 patients of the local cochlear implant centre was measured by Otoplan using high-resolution CT-bone and MRI images, and the determined lengths were compared. RESULTS: No significant difference was found between the cochlear lengths measured, regardless of whether the length measurement was based on a CT or an MRI data set. CONCLUSION: For the determination of cochlear length prior to cochlear implant surgery, MRI images are just as suitable as CT images, therefore CT is not mandatory for length measurement by Otoplan, which could reduce the patient's radiation exposure.

3D-exoscopic microlaryngoscopy in phonosurgery for glottic insufficiency.

PURPOSE: We hypothesized that using a 3D-exoscope (3Dex) in microlaryngoscopic phonosurgery is non-inferior to using a standard operating microscope (OM). To compare the above, we utilized a 3Dex and an OM for microlaryngoscopic vocal fold augmentation with autologous fat in patients with glottic insufficiency and compared the procedure itself and the long-term impact of vocal fold augmentation on subjective and objective voice parameters in both groups. METHODS: 36 patients with glottic insufficiency received microlaryngoscopic laryngeal augmentation with autologous fat. A 3Dex was utilized in 24 cases for visualization and compared to twelve cases in which an OM was used. Voice parameters were evaluated over a period of twelve months. RESULTS: Comparison of operation time and voice parameters between the 3Dex and OM groups did not reveal significant differences. Significant improvement of mean voice quality in all parameters excluding roughness was observed at 3 and 6 months followed then by a slight decrease of voice quality parameters between the 6 and 12 months interval in both groups. CONCLUSION: Our findings indicate no difference concerning operation time and outcome between the use of a 3Dex and an OM in phonosurgery. Our results highlight a significant voice improvement after vocal fold augmentation with autologous fat in glottic insufficiency mediated dysphonia. The smaller viewing system, better ergonomics for the primary surgeon and the assistant and a direct view for the entire surgical team make a 3Dex an interesting alternative for visualization in microlaryngoscopic phonosurgery.

Universal Newborn Hearing Screening Program: 10-Year Outcome and Follow-Up from a Screening Center in Germany.

Regular reporting of quality control is important in newborn hearing screening, ensuring early diagnosis and intervention. This study reports on a population-based newborn hearing screening program in North-Rhine, Germany and a hospital-based screening at a University Hospital for 2007-2016. The two-staged 'screening' and 'follow-up' program involving TEOAE and AABR recruited newborns through participating birth facilities. Results were sent to the regional tracking center, and the data were analyzed based on recommended benchmarks. The percentage of newborns from the participating birth facilities in the region increased from 1.4% in 2007 to 57.5% in 2016. The 10-year coverage rate for these newborns was 98.7%, the referral rate after a failed two-step screening was 3.4%, and the lost-to-follow-up rate was 1%. At the hospital, >95% of the screened newborns completed screening within 30 days, the 10-year referral rate was 5%, and 64% were referred within 3 months of age. The median time for screening completion was 6 days after birth, for referral it was 74 days after birth, and for diagnosis it was 55 days after birth. Regional-centralized tracking centers with uniform structure are necessary for proper quality control. Obligatory participation of birthing facilities and quality reports may improve performance, but the recommended quality criteria need considerable financial and infrastructural expenditure.

Effects of noise and noise reduction on audiovisual speech perception in cochlear implant users: An ERP study.

OBJECTIVE: Hearing with a cochlear implant (CI) is difficult in noisy environments, but the use of noise reduction algorithms, specifically ForwardFocus, can improve speech intelligibility. The current event-related potentials (ERP) study examined the electrophysiological correlates of this perceptual improvement. METHODS: Ten bimodal CI users performed a syllable-identification task in auditory and audiovisual conditions, with syllables presented from the front and stationary noise presented from the sides. Brainstorm was used for spatio-temporal evaluation of ERPs. RESULTS: CI users revealed an audiovisual benefit as reflected by shorter response times and greater activation in temporal and occipital regions at P2 latency. However, in auditory and audiovisual conditions, background noise hampered speech processing, leading to longer response times and delayed auditory-cortex-activation at N1 latency. Nevertheless, activating ForwardFocus resulted in shorter response times, reduced listening effort and enhanced superior-frontal-cortex-activation at P2 latency, particularly in audiovisual conditions. CONCLUSIONS: ForwardFocus enhances speech intelligibility in audiovisual speech conditions by potentially allowing the reallocation of attentional resources to relevant auditory speech cues. SIGNIFICANCE: This study shows for CI users that background noise and ForwardFocus differentially affect spatio-temporal cortical response patterns, both in auditory and audiovisual speech conditions.

Effectiveness and costs of a low-threshold hearing screening programme (HörGeist) for individuals with intellectual disabilities: protocol for a screening study.

INTRODUCTION: Individuals with intellectual disabilities (ID) often suffer from hearing loss, in most cases undiagnosed or inappropriately treated. The implementation of a programme of systematic hearing screening, diagnostics, therapy initiation or allocation and long-term monitoring within the living environments of individuals with ID (nurseries, schools, workshops, homes), therefore, seems beneficial. METHODS AND ANALYSIS: The study aims to assess the effectiveness and costs of a low-threshold screening programme for individuals with ID. Within this programme 1050 individuals with ID of all ages will undergo hearing screening and an immediate reference diagnosis in their living environment (outreach cohort). The recruitment of participants in the outreach group will take place within 158 institutions, for example, schools, kindergartens and places of living or work. If an individual fails the screening assessment, subsequent full audiometric diagnostics will follow and, if hearing loss is confirmed, initiation of therapy or referral to and monitoring of such therapy. A control cohort of 141 participants will receive an invitation from their health insurance provider via their family for the same procedure but within a clinic (clinical cohort). A second screening measurement will be performed with both cohorts 1 year later and the previous therapy outcome will be checked. It is hypothesised that this programme leads to a relevant reduction in the number of untreated or inadequately treated cases of hearing loss and strengthens the communication skills of the newly or better-treated individuals. Secondary outcomes include the age-dependent prevalence of hearing loss in individuals with ID, the costs associated with this programme, cost of illness before-and-after enrolment and modelling of the programme's cost-effectiveness compared with regular care. ETHICS AND DISSEMINATION: The study has been approved by the Institutional Ethics Review Board of the Medical Association of Westphalia-Lippe and the University of Münster (No. 2020-843 f-S). Participants or guardians will provide written informed consent. Findings will be disseminated through presentations, peer-reviewed journals and conferences. TRIAL REGISTRATION NUMBER: DRKS00024804.

Referral rate and false-positive rates in a hearing screening program among high-risk newborns.

AIM: More studies exploring referral rates and false-positive rates are needed to make hearing screening programs in newborns better and cost-effective. Our aim was to study the referral and false-positivity rates among high-risk newborns in our hearing screening program and to analyze the factors potentially associated with false-positive hearing screening test results. METHODS: A retrospective cohort study was done among the newborns hospitalized at a university hospital from January 2009 to December 2014 that underwent hearing screening with a two-staged AABR screening protocol. Referral rates and false-positivity rates were calculated and possible risk factors for false-positivity were analyzed. RESULTS: 4512 newborns were screened for hearing loss in the neonatology department. The referral rate for the two-staged AABR-only screening was 3.8% with false-positivity being 2.9%. Our study showed that the higher the birthweight or gestational age of the newborn, the lower the odds of the hearing screening results being false-positive, and the higher the chronological age of the infant at the time of screening, the higher the odds of the results being false-positive. Our study did not show a clear association between the mode of delivery or gender and false-positivity. CONCLUSION: Among high-risk infants, prematurity and low-birthweight increased the rate of false-positivity in the hearing screening, and the chronological age at the time of the test seems to be significantly associated with false-positivity.

A mutation in ATP11A causes autosomal-dominant auditory neuropathy type 2.

Auditory synaptopathy/neuropathy (AS/AN) is a distinct type of sensorineural hearing loss in which the cochlear sensitivity to sound (i.e. active cochlear amplification by outer hair cells) is preserved whereas sound encoding by inner hair cells and/or auditory nerve fibers is disrupted owing to genetic or environmental factors. Autosomal-dominant auditory neuropathy type 2 (AUNA2) was linked either to chromosomal bands 12q24 or 13q34 in a large German family in 2017. By whole-genome sequencing, we now detected a 5500 bp deletion in ATP11A on chromosome 13q34 segregating with the phenotype in this family. ATP11A encodes a P-type ATPase that translocates phospholipids from the exoplasmic to the cytoplasmic leaflet of the plasma membrane. The deletion affects both isoforms of ATP11A and activates a cryptic splice site leading to the formation of an alternative last exon. ATP11A carrying the altered C-terminus loses its flippase activity for phosphatidylserine. Atp11a is expressed in fibers and synaptic contacts of the auditory nerve and in the cochlear nucleus in mice, and conditional Atp11a knockout mice show a progressive reduction of the spiral ganglion neuron compound action potential, recapitulating the human phenotype of AN. By combining whole-genome sequencing, immunohistochemistry, in vitro functional assays and generation of a mouse model, we could thus identify a partial deletion of ATP11A as the genetic cause of AUNA2.

Electrophysiological differences and similarities in audiovisual speech processing in CI users with unilateral and bilateral hearing loss.

Hearing with a cochlear implant (CI) is limited compared to natural hearing. Although CI users may develop compensatory strategies, it is currently unknown whether these extend from auditory to visual functions, and whether compensatory strategies vary between different CI user groups. To better understand the experience-dependent contributions to multisensory plasticity in audiovisual speech perception, the current event-related potential (ERP) study presented syllables in auditory, visual, and audiovisual conditions to CI users with unilateral or bilateral hearing loss, as well as to normal-hearing (NH) controls. Behavioural results revealed shorter audiovisual response times compared to unisensory conditions for all groups. Multisensory integration was confirmed by electrical neuroimaging, including topographic and ERP source analysis, showing a visual modulation of the auditory-cortex response at N1 and P2 latency. However, CI users with bilateral hearing loss showed a distinct pattern of N1 topography, indicating a stronger visual impact on auditory speech processing compared to CI users with unilateral hearing loss and NH listeners. Furthermore, both CI user groups showed a delayed auditory-cortex activation and an additional recruitment of the visual cortex, and a better lip-reading ability compared to NH listeners. In sum, these results extend previous findings by showing distinct multisensory processes not only between NH listeners and CI users in general, but even between CI users with unilateral and bilateral hearing loss. However, the comparably enhanced lip-reading ability and visual-cortex activation in both CI user groups suggest that these visual improvements are evident regardless of the hearing status of the contralateral ear.

Side-of-Implantation Effect on Functional Asymmetry in the Auditory Cortex of Single-Sided Deaf Cochlear-Implant Users.

Cochlear implants (CIs) allow to restore the hearing function in profoundly deaf individuals. Due to the degradation of the stimulus by CI signal processing, implanted individuals with single-sided deafness (SSD) have the specific challenge that the input highly differs between their ears. The present study compared normal-hearing (NH) listeners (N = 10) and left- and right-ear implanted SSD CI users (N = 10 left, N = 9 right), to evaluate cortical speech processing between CI- and NH-ears and to explore for side-of-implantation effects. The participants performed a two-deviant oddball task, separately with the left and the right ear. Auditory event-related potentials (ERPs) in response to syllables were compared between proficient and non-proficient CI users, as well as between CI and NH ears. The effect of the side of implantation was analysed on the sensor and the source level. CI proficiency could be distinguished based on the ERP amplitudes of the N1 and the P3b. Moreover, syllable processing via the CI ear, when compared to the NH ear, resulted in attenuated and delayed ERPs. In addition, the left-ear implanted SSD CI users revealed an enhanced functional asymmetry in the auditory cortex than right-ear implanted SSD CI users, regardless of whether the syllables were perceived via the CI or the NH ear. Our findings reveal that speech-discrimination proficiency in SSD CI users can be assessed by N1 and P3b ERPs. The results contribute to a better understanding of the rehabilitation success in SSD CI users by showing that cortical speech processing in SSD CI users is affected by CI-related stimulus degradation and experience-related functional changes in the auditory cortex.

Speech perception in noise and sound localization using different microphone modes in pediatric bilateral cochlear implant users.

OBJECTIVE: The aim of the study was to investigate if a directional microphone mode improves speech perception in noise and sound localization in experienced pediatric bilateral cochlear implant users. METHODS: 15 bilaterally implanted children were included in the analysis. Speech perception in 4 noise conditions (S0N0, S0N90, S0N-90, S0N180) and sound localization were measured when using the OPUS 2 audio processor (omnidirectional mode) and the SONNET audio processor (omnidirectional and natural mode). RESULTS: Speech perception in all 4 noise conditions was better with the SONNET natural mode than with the omnidirectional mode of either SONNET or OPUS 2. The root-mean-square error of the sound localization test was smaller with the natural mode of SONNET than with the omnidirectional mode of either SONNET or OPUS 2. The performance of the audio processors in the omnidirectional mode did not differ significantly except in the S0N0 condition of the speech perception test. CONCLUSION: The natural microphone mode of the SONNET audio processor improved speech perception in noise and sound localization in bilaterally implanted children.

The timecourse of multisensory speech processing in unilaterally stimulated cochlear implant users revealed by ERPs.

A cochlear implant (CI) is an auditory prosthesis which can partially restore the auditory function in patients with severe to profound hearing loss. However, this bionic device provides only limited auditory information, and CI patients may compensate for this limitation by means of a stronger interaction between the auditory and visual system. To better understand the electrophysiological correlates of audiovisual speech perception, the present study used electroencephalography (EEG) and a redundant target paradigm. Postlingually deafened CI users and normal-hearing (NH) listeners were compared in auditory, visual and audiovisual speech conditions. The behavioural results revealed multisensory integration for both groups, as indicated by shortened response times for the audiovisual as compared to the two unisensory conditions. The analysis of the N1 and P2 event-related potentials (ERPs), including topographic and source analyses, confirmed a multisensory effect for both groups and showed a cortical auditory response which was modulated by the simultaneous processing of the visual stimulus. Nevertheless, the CI users in particular revealed a distinct pattern of N1 topography, pointing to a strong visual impact on auditory speech processing. Apart from these condition effects, the results revealed ERP differences between CI users and NH listeners, not only in N1/P2 ERP topographies, but also in the cortical source configuration. When compared to the NH listeners, the CI users showed an additional activation in the visual cortex at N1 latency, which was positively correlated with CI experience, and a delayed auditory-cortex activation with a reversed, rightward functional lateralisation. In sum, our behavioural and ERP findings demonstrate a clear audiovisual benefit for both groups, and a CI-specific alteration in cortical activation at N1 latency when auditory and visual input is combined. These cortical alterations may reflect a compensatory strategy to overcome the limited CI input, which allows the CI users to improve the lip-reading skills and to approximate the behavioural performance of NH listeners in audiovisual speech conditions. Our results are clinically relevant, as they highlight the importance of assessing the CI outcome not only in auditory-only, but also in audiovisual speech conditions.

[Is Flying or Diving risky after cochlear implantation? Examination in a pressure chamber]. / Ist Fliegen oder Tauchen riskant für CI-Träger? ­ Untersuchungen in einer Druckkammer.

OBJECTIVE: Complications after cochlear implantation are relatively rare but patients are asked to follow certain behavioral rules. Until now there is no evidence if pressure changes that occur during flying and diving are safe for patients after cochlear implantation. For example, no recommendation exists for SCUBA- diving activities. MATERIALS AND METHODS: In a hypo-/hyperbaric pressure chamber patients after cochlear implantation were exposed to a standardized profile of decompression and compression simulating a flight in a common airplane and a dive. Pre and after the exposure in the pressure chamber, ENT examination and a control of impedances of the cochlear implant were performed. Additionally, patients filled in a questionnaire about complaints they had experienced in the pressure chamber or after. RESULTS: A total of 11 subjects (17 ears with CI) were examined in the pressure chamber. 2/3 of the subjects stated that they had slight complaints during the examination. Only in one patient the measurement needed to be stopped due to pain. Seven patients showed a vascular injection of the malleus in ear microscopy. In none of the patients there was a subjective change in hearing after the examination. Objective measurements of the impedance did not show relevant changes. CONCLUSION: The exposure of cochlear implanted patients to overpressure and underpressure in a pressure chamber did not result in any significant deviation of the impedances, so that no further adjustment was necessary. Since there are no certified in vivo studies on pressure changes while diving and flying with a cochlear implant, further studies are required in order to be able to adequately advise CI patients about diving and flying.

Age effects on cognitive functions and speech-in-noise processing: An event-related potential study with cochlear-implant users and normal-hearing listeners.

A cochlear implant (CI) can partially restore hearing in individuals with profound sensorineural hearing loss. However, electrical hearing with a CI is limited and highly variable. The current study aimed to better understand the different factors contributing to this variability by examining how age affects cognitive functions and cortical speech processing in CI users. Electroencephalography (EEG) was applied while two groups of CI users (young and elderly; N = 13 each) and normal-hearing (NH) listeners (young and elderly; N = 13 each) performed an auditory sentence categorization task, including semantically correct and incorrect sentences presented either with or without background noise. Event-related potentials (ERPs) representing earlier, sensory-driven processes (N1-P2 complex to sentence onset) and later, cognitive-linguistic integration processes (N400 to semantically correct/incorrect sentence-final words) were compared between the different groups and speech conditions. The results revealed reduced amplitudes and prolonged latencies of auditory ERPs in CI users compared to NH listeners, both at earlier (N1, P2) and later processing stages (N400 effect). In addition to this hearing-group effect, CI users and NH listeners showed a comparable background-noise effect, as indicated by reduced hit rates and reduced (P2) and delayed (N1/P2) ERPs in conditions with background noise. Moreover, we observed an age effect in CI users and NH listeners, with young individuals showing improved specific cognitive functions (working memory capacity, cognitive flexibility and verbal learning/retrieval), reduced latencies (N1/P2), decreased N1 amplitudes and an increased N400 effect when compared to the elderly. In sum, our findings extend previous research by showing that the CI users' speech processing is impaired not only at earlier (sensory) but also at later (semantic integration) processing stages, both in conditions with and without background noise. Using objective ERP measures, our study provides further evidence of strong age effects on cortical speech processing, which can be observed in both the NH listeners and the CI users. We conclude that elderly individuals require more effortful processing at sensory stages of speech processing, which however seems to be at the cost of the limited resources available for the later semantic integration processes.

Taste-strip gustometry in cochlear implanted patients.

OBJECTIVE: Investigation of the gustatory function in a large cohort of cochlear implanted patients using lateralized taste-strip tests. PATIENTS AND METHODS: One hundred and seven unilaterally or bilaterally profoundly hearing impaired or deaf patients who received cochlear implants (n = 113) were included in this study. Data on gustometry, subjective gustatory dysfunction, and the detailed surgical procedure were acquired retrospectively. Gustatory function, assessed using lateralized taste-strip tests, was performed the day before, 3 days after cochlear implantation, and on the day of the initial CI adjustment (39 days ±7.3 SD). RESULTS: Averaged taste-strip scores of the cohort declined significantly from preoperatively 12.3 [11.8; 12.7] (mean [95% confidence intervals]) to 10.5 [9.7; 11.2] on the implanted side about 6 weeks after surgery. Patients with intraoperatively exposed and rerouted, or a severed, chorda tympani nerve (CTN) showed significantly reduced unilateral postoperative scores (10.1 [8.8; 11.4] and 9.3 [8.1; 10.5], respectively), when compared to not exposing or to leaving a bony layer over the CTN. Total taste-strip test scores showed a significant decline 6 weeks postoperatively in CI-patients expressing a subjective gustatory dysfunction (from 23.6 [21.4; 25.8] to 17.5 [14.2; 20.8]), as opposed to patients with a documented subjectively normal taste. CONCLUSION: We consider postoperative gustatory dysfunction as a relevant side effect post cochlear implantation, at least within the first month. Taste-strip based gustometry is a suitable diagnostic tool to assess taste function in CI patients and is recommended to be performed routinely. LEVEL OF EVIDENCE: 3, retrospective, nonrandomized follow-up study.

Speech Recognition With Informational and Energetic Maskers in Patients With Single-Sided Deafness After Cochlear Implantation.

Purpose The aim of the study was to assess the susceptibility to energetic and informational masking in patients with single-sided deafness (SSD) with one normal-hearing (NH) ear and a cochlear implant (CI) in the contralateral ear, understand the effect on speech recognition when spatially separating noise and speech maskers, and investigate the influence of the CI in situations with energetic and informational masking. Method Speech recognition was measured in the presence of either a modulated speech-shaped noise or one of two competing speech maskers in 11 SSD-CI listeners. The speech maskers were manipulated with respect to fundamental frequency to consider the effect of different voices. Measurements were conducted in the unaided (NH) and aided (NHCI) conditions. Spatial release from masking (SRM) was calculated for each masker type and both listening conditions (NH and NHCI) by subtracting scores of the colocated target and masker condition (S0N0) from the spatially separated target and masker conditions (S0N≠0). Results Speech recognition was highly variable depending on the type of masker. SRM occurred in the unaided (NH) and aided (NHCI) conditions when the speech masker had the same gender as the target talker. Adding the CI improved speech recognition when this speech masker was ipsilateral to the NH ear. Conclusions The amount of informational masking is substantial in SSD-CI listeners with both colocated and spatially separated target and masker signals. The contribution of SRM to better speech recognition largely depends on the masker and is considerable when no differences in voices between the target and the competing talker occur. There is only a slight improvement in speech recognition by adding the CI.

The diagnostic value of computed tomography in delayed complications after cochlear implantation.

BACKGROUND: Delayed complications after cochlear implant (CI) surgery can result in the need for revision surgery. Temporal bone computed tomography (tCT) is frequently used in the diagnostic work-up for these patients. AIMS/OBJECTIVES: We aimed to test for the value of tCT in delayed complications after CI surgery. MATERIAL AND METHODS: Retrospective chart review including all patients with CI who were consecutively enrolled in our academic tertiary care centre and received a tCT due to delayed complications between January 2008 and December 2017. RESULTS: A total of 85 patients with a mean age of 28 years at CI surgery were identified. Mean time between CI and tCT was 4.3 years. Reasons for performance of tCT were device malfunction (20%), cephalgia (20%), scalp hematoma/seroma (15.3%), device failure (11.8%), vertigo (10.6%), local infection (7.1%), trauma (5.9%), meningism (3.5%), tinnitus (3.5%) and facial palsy (2.4%). No abnormalities in tCT were detected in 82.4%. However, an abnormal tCT was a predictor for surgical therapy (p < .001). CONCLUSIONS AND SIGNIFICANCE: We recommend the performance of tCT in CI patients with delayed complications to identify or rule out pathology in order to choose the most ideal and relevant individual treatment.

Letter to the Editor Concerning Skuk et al., "Parameter-Specific Morphing Reveals Contributions of Timbre and Fundamental Frequency Cues to the Perception of Voice Gender and Age in Cochlear Implant Users".

Purpose The purpose of this letter is to compare results by Skuk et al. (2020) with Meister et al. (2016) and to point to a potential general influence of stimulus type. Conclusion Our conclusion is that presenting sentences may give cochlear implant recipients the opportunity to use timbre cues for voice perception. This might not be the case when presenting brief and sparse stimuli such as consonant-vowel-consonant or single words, which were applied in the majority of studies.

Comparison of the Effects of Two Cochlear Implant Fine Structure Coding Strategies on Speech Perception.

Purpose This study aims to investigate the effect of upgrading from the fine structure processing (FSP) coding strategy to the novel fine structure strategy "FS4" in adults in adults with cochlear implants manufactured by MED-EL GmbH (Innsbruck, Austria). Method A crossover, double-blinded study was conducted for 12 weeks. Twelve adult participants were randomly assigned to two groups. During the first 6-week test interval, one group continued to use their everyday FSP strategy, whereas the other group was upgraded to the FS4 strategy. In the second 6-week interval, the two groups switched coding strategies. Speech perception was measured at the end of each test interval with the Oldenburg Sentence Test and the Göttingen Sentence Test. Participants completed the Speech, Spatial and Qualities of Hearing Scale at the end of each test interval and a simple preference test at the end of the study. Results There was no significant difference in speech perception test results obtained with the Oldenburg Sentence Test and the Göttingen Sentence Test, neither in quiet nor in noise. Participants' Speech, Spatial and Qualities of Hearing Scale self-evaluation and preference test results showed that the two coding strategies had similar effects on their hearing perception. No clear preference for either of the strategies was found. Conclusions Speech perception test results and the participants' level of satisfaction were similar for the two FS coding strategies. Despite differences in the presentation of temporal fine structure between FSP and FS4, a clear benefit of the newer FS4 strategy could not be shown.