Cochlear Implantation Outcomes in Pediatric Unilateral Hearing Loss: Impact of Device Use and Direct Input.

OBJECTIVE: To investigate the impact of daily cochlear implant (CI) use on speech perception outcomes among children with unilateral hearing loss (UHL). STUDY DESIGN: Multi-institutional retrospective case series of pediatric patients with UHL who underwent CI between 2018 to 2022. SETTING: Three tertiary children's hospitals. METHODS: Demographics were obtained including duration of deafness and age at CI. Best consonant-nucleus-consonant (CNC) word scores and data logs describing hours of CI usage were assessed postimplantation. Use of direct audio input (DAI) during rehabilitation was recorded. RESULTS: Twenty-seven children were included, with a mean age at CI of 7.8 years. Mean datalogging time was 7.8 ± 3.0 hours/day. 40.7% of children utilized daily DAI. The mean CNC score using the best score during the study period was 34.9%. There was no significant correlation between hours of CI usage and CNC score. There was a significant improvement in CNC score associated with whether the child used DAI during rehabilitation (CNC 50.91% [yes] vs 23.81% [no]), which remained significant when adjusting for age at CI, duration of deafness, and data log hours. CONCLUSION: Unlike children with bilateral hearing loss and CI, children with UHL and CI demonstrate no significant correlation between hours of daily CI usage and CNC scores. However, children who used DAI during postoperative rehabilitation achieved significantly higher CNC scores than those who did not. This suggests that rehabilitation focused on isolated listening with the implanted ear maybe critical in optimizing outcomes with CI in UHL patients.

Combining Intraoperative Electrocochleography with Robotics-Assisted Electrode Array Insertion.

OBJECTIVE: To describe the use of robotics-assisted electrode array (EA) insertion combined with intraoperative electrocochleography (ECochG) in hearing preservation cochlear implant surgery. STUDY DESIGN: Prospective, single-arm, open-label study. SETTING: All procedures and data collection were performed at a single tertiary referral center. PATIENTS: Twenty-one postlingually deaf adult subjects meeting Food and Drug Administration indication criteria for cochlear implantation with residual acoustic hearing defined as thresholds no worse than 65 dB at 125, 250, and 500 Hz. INTERVENTION: All patients underwent standard-of-care unilateral cochlear implant surgery using a single-use robotics-assisted EA insertion device and concurrent intraoperative ECochG. MAIN OUTCOME MEASURES: Postoperative pure-tone average over 125, 250, and 500 Hz measured at initial activation and subsequent intervals up to 1 year afterward. RESULTS: Twenty-two EAs were implanted with a single-use robotics-assisted insertion device and simultaneous intraoperative ECochG. Fine control over robotic insertion kinetics could be applied in response to changes in ECochG signal. Patients had stable pure-tone averages after activation with normal impedance and neural telemetry responses. CONCLUSIONS: Combining robotics-assisted EA insertion with intraoperative ECochG is a feasible technique when performing hearing preservation implant surgery. This combined approach may provide the surgeon a means to overcome the limitations of manual insertion and respond to cochlear feedback in real-time.

American Cochlear Implant Alliance Task Force: Recommendations for Determining Cochlear Implant Candidacy in Adults.

The indications for cochlear implantation have expanded over time due to evidence demonstrating identification and implantation of appropriate cochlear implant (CI) candidates lead to significant improvements in speech recognition and quality of life (QoL). However, clinical practice is variable, with some providers using outdated criteria and others exceeding current labeled indications. As a results, only a fraction of those persons who could benefit from CI technology receive it. This document summarizes the current evidence for determining appropriate referrals for adults with bilateral hearing loss into CI centers for formal evaluation by stressing the importance of treating each ear individually and a "revised 60/60 rule". By mirroring contemporary clinical practice and available evidence, these recommendations will also provide a standardized testing protocol for CI candidates using a team-based approach that prioritizes individualized patient care. This manuscript was developed by the Adult Cochlear Implantation Candidacy Task Force of the American Cochlear Implant Alliance using review of the existing literature and clinical consensus. LEVEL OF EVIDENCE: N/A Laryngoscope, 134:S1-S14, 2024.

Neural Correlates of Individual Differences in Speech-in-Noise Performance in a Large Cohort of Cochlear Implant Users.

OBJECTIVES: Understanding speech-in-noise (SiN) is a complex task that recruits multiple cortical subsystems. Individuals vary in their ability to understand SiN. This cannot be explained by simple peripheral hearing profiles, but recent work by our group ( Kim et al. 2021 , Neuroimage ) highlighted central neural factors underlying the variance in SiN ability in normal hearing (NH) subjects. The present study examined neural predictors of SiN ability in a large cohort of cochlear-implant (CI) users. DESIGN: We recorded electroencephalography in 114 postlingually deafened CI users while they completed the California consonant test: a word-in-noise task. In many subjects, data were also collected on two other commonly used clinical measures of speech perception: a word-in-quiet task (consonant-nucleus-consonant) word and a sentence-in-noise task (AzBio sentences). Neural activity was assessed at a vertex electrode (Cz), which could help maximize eventual generalizability to clinical situations. The N1-P2 complex of event-related potentials (ERPs) at this location were included in multiple linear regression analyses, along with several other demographic and hearing factors as predictors of SiN performance. RESULTS: In general, there was a good agreement between the scores on the three speech perception tasks. ERP amplitudes did not predict AzBio performance, which was predicted by the duration of device use, low-frequency hearing thresholds, and age. However, ERP amplitudes were strong predictors for performance for both word recognition tasks: the California consonant test (which was conducted simultaneously with electroencephalography recording) and the consonant-nucleus-consonant (conducted offline). These correlations held even after accounting for known predictors of performance including residual low-frequency hearing thresholds. In CI-users, better performance was predicted by an increased cortical response to the target word, in contrast to previous reports in normal-hearing subjects in whom speech perception ability was accounted for by the ability to suppress noise. CONCLUSIONS: These data indicate a neurophysiological correlate of SiN performance, thereby revealing a richer profile of an individual's hearing performance than shown by psychoacoustic measures alone. These results also highlight important differences between sentence and word recognition measures of performance and suggest that individual differences in these measures may be underwritten by different mechanisms. Finally, the contrast with prior reports of NH listeners in the same task suggests CI-users performance may be explained by a different weighting of neural processes than NH listeners.

A Steadier Hand: The First Human Clinical Trial of a Single-Use Robotic-Assisted Surgical Device for Cochlear Implant Electrode Array Insertion.

OBJECTIVE: To evaluate the safety and utility of an investigational robotic-assisted cochlear implant insertion system. STUDY DESIGN: Prospective, single-arm, open-label study under abbreviated Investigational Device Exemption requirements. SETTING: All procedures were performed, and all data were collected, at a single tertiary referral center. PATIENTS: Twenty-one postlingually deafened adult subjects that met Food and Drug Administration indication criteria for cochlear implantation. INTERVENTION: All patients underwent standard-of-care surgery for unilateral cochlear implantation with the addition of a single-use robotic-assisted insertion device during cochlear electrode insertion. MAIN OUTCOME MEASURES: Successful insertion of cochlear implant electrode array, electrode array insertion time, postoperative implant function. RESULTS: Successful robotic-assisted insertion of lateral wall cochlear implant electrode arrays was achieved in 20 (95.2%) of 21 patients. One insertion was unable to be achieved by either robotic-assisted or manual insertion methods, and the patient was retrospectively found to have a preexisting cochlear fracture. Mean intracochlear electrode array insertion time was 3 minutes 15 seconds. All implants with successful robotic-assisted electrode array insertion (n = 20) had normal impedance and neural response telemetry measures for up to 6 months after surgery. CONCLUSIONS: Here we report the first human trial of a single-use robotic-assisted surgical device for cochlear implant electrode array insertion. This device successfully and safely inserted lateral wall cochlear implant electrode arrays from the three device manufacturers with devices approved but he Food and Drug Administration.

Clinical perspective on hearing preservation in cochlear implantation, the University of Iowa experience.

Preservation of residual acoustic hearing has emerged as an important concept for those individuals undergoing cochlear implantation with residual low frequency hearing. Acoustic plus electric speech processing improves hearing outcomes in quiet, enables melody recognition, preserves spatial hearing if there is acoustic hearing in both ears and significantly improves hearing in noise. The development of our experience with acoustic plus electric processing is reviewed along with clinical trials and patient outcomes that our team has documented over the past twenty years.

The Influence of Forced Social Isolation on the Auditory Ecology and Psychosocial Functions of Listeners With Cochlear Implants During COVID-19 Mitigation Efforts.

OBJECTIVES: The impact of social distancing on communication and psychosocial variables among individuals with hearing impairment during COVID-19 pandemic. It was our concern that patients who already found themselves socially isolated (Wie et al. 2010) as a result of their hearing loss would be perhaps more susceptible to changes in their communication habits resulting in further social isolation, anxiety, and depression. We wanted to better understand how forced social isolation (as part of COVID-19 mitigation) effected a group of individuals with hearing impairment from an auditory ecology and psychosocial perspective. We hypothesized that the listening environments would be different as a result of social isolation when comparing subject's responses regarding activities and participation before COVID-19 and during the COVID-19 pandemic. This change would lead to an increase in experienced and perceived social isolation, anxiety, and depression. DESIGN: A total of 48 adults with at least 12 months of cochlear implant (CI) experience reported their listening contexts and experiences pre-COVID and during-COVID using Ecological Momentary Assessment (EMA; methodology collecting a respondent's self-reports in their natural environments) through a smartphone-based app, and six paper and pencil questionnaires. The Smartphone app and paper-pencil questionnaires address topics related to their listening environment, social isolation, depression, anxiety, lifestyle and demand, loneliness, and satisfaction with amplification. Data from these two-time points were compared to better understand the effects of social distancing on the CI recipients' communication abilities. RESULTS: EMA demonstrated that during-COVID CI recipients were more likely to stay home or be outdoors. CI recipients reported that they were less likely to stay indoors outside of their home relative to the pre-COVID condition. Social distancing also had a significant effect on the overall signal-to-noise ratio of the environments indicating that the listening environments had better signal-to-noise ratios. CI recipients also reported better speech understanding, less listening effort, less activity limitation due to hearing loss, less social isolation due to hearing loss, and less anxiety due to hearing loss. Retrospective questionnaires indicated that social distancing had a significant effect on the social network size, participant's personal image of themselves, and overall loneliness. CONCLUSIONS: Overall, EMA provided us with a glimpse of the effect that forced social isolation has had on the listening environments and psychosocial perspectives of a select number of CI listeners. CI participants in this study reported that they were spending more time at home in a quieter environments during-COVID. Contrary to our hypothesis, CI recipients overall felt less socially isolated and reported less anxiety resulting from their hearing difficulties during-COVID in comparison to pre-COVID. This, perhaps, implies that having a more controlled environment with fewer speakers provided a more relaxing listening experience.

Nucleus Hybrid S12: Multicenter Clinical Trial Results.

OBJECTIVES/HYPOTHESIS: The use of a short 10-mm/10-electrode cochlear implant to preserve low-frequency residual hearing was investigated. This report describes the 12-month outcomes of this multicenter clinical trial. STUDY DESIGN: Single-subject design. METHODS: Twenty-eight subjects with low-frequency hearing at or better than 60 dB HL at 500 Hz and severe high-frequency hearing loss were implanted with a Nucleus Hybrid S12 implant in their poorer ear. Speech perception in quiet using Consonant-Nucleus-Consonant (CNC) words and sentences in noise using AzBio sentences was collected pre- and postoperatively at 3, 6, and 12 months. Subjective reporting using the Speech, Spatial, and Qualities of Hearing Scale (SSQ) questionnaire was also collected pre- and postoperatively. RESULTS: Functional hearing preservation was accomplished in 96% of subjects. At 3 and 6 months, 86% of the 28 subjects had maintained functional hearing. By 12 months, 23 out of 27 subjects (85%) had maintained functional hearing (one subject with functional hearing at 6 months withdrew from the study prior to the 12-month visit). Speech perception results demonstrated that 81% of the participants on CNC words and 77% with AzBio sentences in noise had significant improvements using their everyday listening condition at 12 months compared to preoperative performance with bilateral hearing aids. Furthermore, preoperative to 12 months postoperative subjective ratings showed significant improvements for the SSQ. CONCLUSIONS: This study demonstrates that a high degree of hearing preservation enabling acoustic-electric hearing and improvement in speech understanding in quiet and in noise can be accomplished using a short-electrode 10-mm cochlear implant. LEVEL OF EVIDENCE: 2c Laryngoscope, 130:E548-E558, 2020.

Bilateral Cochlear Implants Using Two Electrode Lengths in Infants With Profound Deafness.

OBJECTIVE: The goal of this investigation was to determine if a short electrode in one ear and standard electrode in the contralateral ear could be an option for infants with congenital profound deafness to theoretically preserve the structures of the inner ear. Similarities in performance between ears and compared with a control group of infants implanted with bilateral standard electrodes was evaluated. STUDY DESIGN: Repeated-measure, single-subject experiment. SETTING: University of Iowa-Department of Otolaryngology. PARTICIPANTS: Nine infants with congenital profound bilateral sensorineural hearing loss. INTERVENTION(S): Short and standard implants. MAIN OUTCOME MEASURE(S): Early speech perception test (ESP), children's vowel, phonetically balanced-kindergarten (PB-K) word test, and preschool language scales-3 (PLS-3). RESULTS: ESP scores showed performance reaching a ceiling effect for the individual short and standard ears and bilaterally. The children's vowel and PB-K word results indicated significant (both p < 0.001) differences between the two ears. Bilateral comparisons to age-matched children with standard bilateral electrodes showed no significant differences (p = 0.321) in performance. Global language performance for six children demonstrated standard scores around 1 standard deviation (SD) of the mean. Two children showed scores below the mean, but can be attributed to inconsistent device usage. Averaged total language scores between groups showed no difference in performance (p = 0.293). CONCLUSIONS: The combined use of a short electrode and standard electrode might provide an option for implantation with the goal of preserving the cochlear anatomy. However, further studies are needed to understand why some children have or do not have symmetric performance.

Acoustic plus electric speech processing: Long-term results.

OBJECTIVE: Few studies have investigated the stability of residual hearing and speech perception outcomes in individuals who were implanted with a shorter electrode device. STUDY DESIGN: Longitudinal, single-subject design. METHODS: Fifty subjects who received a Nucleus Hybrid (Cochlear, Sydney, Australia) short electrode cochlear implant (CI) and had a minimum of 2 years (and up to 15 years) of postoperative longitudinal experience were included in this study. Twenty-three subjects received a Nucleus Hybrid S8 (S8); 14 subjects received a Nucleus Hybrid L24 (L24); and 13 received a Nucleus Hybrid S12 (S12). Audiometric thresholds and consonant-nucleus-consonant (CNC) words were collected pre- and postoperatively for up to 15 years for the S8 subjects and for up to 7 years for the S12 and L24 subjects. AzBio Sentences in multi-talker babble was collected for up to 7 years on the S12 and L24 subjects. RESULTS: Longitudinally, 83% of the S8 subjects, 92% of the S12 subjects, and 86% of the L24 subjects maintained a functional hearing pure-tone average (PTA) (125-500 Hz). Predicted change using a piecewise linear mixed model in PTA over time showed a postoperative linear decrease in hearing for each group until 0.5 years, after which the PTA stabilizes and is maintained. The averaged individual data for CNC and AzBio sentences show a significant improvement in scores by 0.25 to 0.5 years postimplantation, after which scores start to reach their maximum. CONCLUSION: This long-term study demonstrates that acoustic-electric processing hearing and improvement in speech understanding in quiet and in noise can be accomplished and sustained for many years with a short electrode CI. LEVEL OF EVIDENCE: 2C. Laryngoscope, 128:473-481, 2018.

Successful Hearing Preservation After Reimplantation of a Failed Hybrid Cochlear Implant.

Objective: The purpose of this case study was to demonstrate hearing preservation of a subject who was implanted with a 10-mm short electrode cochlear implant that was determined to be malfunctioning at 6 months postimplantation and was explanted and reimplanted with a 16-mm short electrode device.Study Design: Single-subject case study.Setting: Research hospital.Patient: A 60-year old female with a history of gradual progressive bilateral steeply sloping sensorineural hearing loss.Intervention: Rehabilitative.Main Outcome Measure(s): Audiometric data and speech perception in quiet and in noise were collected pre- and postoperatively at 3 and 6 months with the 10-mm short electrode device and pre-explantation and postoperatively at 3, 6, and 12 months with the 16-mm short electrode device.Results: Functional hearing preservation was accomplished following surgical implantation of both short electrode devices. Overall, the subject had a 22 dB HL total shift in pure-tone-average (0.125­1 kHz) after two cochlear implant surgeries. Speech perception growth was limited over the 6 months the subject was implanted with the 10-mm short electrode device. After 3 months of experience with the 16-mm short electrode device, the subject experienced significant improvements in both speech perception in quiet and in noise.Conclusions: The inner ear might be more robust than once thought, as was determined through preservation of residual hearing after implantation of two hearing preservation cochlear implants and one device explantation. Furthermore, it is important that hearing professionals remain cognizant of unusual speech perception patterns associated with the cochlear implant. Key Words: Hearing preservation­Residual hearing­Short electode. [Corrected]

Hearing preservation among patients undergoing cochlear implantation.

INTRODUCTION: Despite successful preservation of low-frequency hearing in patients undergoing cochlear implantation (CI) with shorter electrode lengths, there is still controversy regarding which electrodes maximize hearing preservation (HP). The thin straight electrode array (TSEA) has been suggested as a full cochlear coverage option for HP. However, very little is known regarding its HP potential. METHODS: A retrospective review was performed at two tertiary academic medical centers, reviewing the electronic records for 52 patients (mean, 58.2 yr; range, 11-85 yr) implanted with the Cochlear Nucleus CI422 Slim Straight (Centennial, CO, USA) electrode array, referred to herein as the thin straight electrode array or TSEA. All patients had a preoperative low-frequency pure-tone average (LFPTA) of 85 dB HL or less. Hearing thresholds were measured at initial activation (t1) and 6 months after activation (t2). HP was assessed by evaluating functional HP using a cutoff level of 85 dB HL PTA. RESULTS: At t1, 54% of the subjects had functional hearing; 33% of these subjects had an LFPTA between 71 and 85 dB HL, and 17% had an LFPTA between 56 and 70 dB HL. At t2, 47% of the patients had functional hearing, with 31% having an LFPTA between 71 and 85 dB HL. DISCUSSION: Preliminary research suggests that the TSEA has the potential to preserve functional hearing in 54% of patients at t1. However, 22% (n = 6) of the patients who had functional hearing at t1 (n = 28) lost their hearing between t1 and t2. Further studies are needed to evaluate factors that influence HP with the TSEA electrode and determine the speech perception benefits using electric and acoustic hearing over electric alone.

Longitudinal speech perception and language performance in pediatric cochlear implant users: the effect of age at implantation.

OBJECTIVES: Few studies have examined the long-term effect of age at implantation on outcomes using multiple data points in children with cochlear implants. The goal of this study was to determine whether age at implantation has a significant, lasting impact on speech perception, language, and reading performance for children with prelingual hearing loss. DESIGN: A linear mixed-model framework was used to determine the effect of age at implantation on speech perception, language, and reading abilities in 83 children with prelingual hearing loss who received cochlear implants by the age of 4 years. The children were divided into two groups based on their age at implantation: (1) under 2 years of age and (2) between 2 and 3.9 years of age. Differences in model-specified mean scores between groups were compared at annual intervals from 5 to 13 years of age for speech perception, and 7 to 11 years of age for language and reading. RESULTS: After controlling for communication mode, device configuration, and preoperative pure-tone average, there was no significant effect of age at implantation for receptive language by 8 years of age, expressive language by 10 years of age, reading by 7 years of age. In terms of speech-perception outcomes, significance varied between 7 and 13 years of age, with no significant difference in speech-perception scores between groups at ages 7, 11, and 13 years. Children who used oral communication (OC) demonstrated significantly higher speech-perception scores than children who used total communication (TC). OC users tended to have higher expressive language scores than TC users, although this did not reach significance. There was no significant difference between OC and TC users for receptive language or reading scores. CONCLUSIONS: Speech perception, language, and reading performance continue to improve over time for children implanted before 4 years of age. The present results indicate that the effect of age at implantation diminishes with time, particularly for higher-order skills such as language and reading. Some children who receive cochlear implants after the age of 2 years have the capacity to approximate the language and reading skills of their earlier-implanted peers, suggesting that additional factors may moderate the influence of age at implantation on outcomes over time.

Subtotal petrosectomy and mastoid obliteration in adult and pediatric cochlear implant recipients.

OBJECTIVE: To investigate the effect of subtotal petrosectomy and mastoid obliteration (SPMO) on the overall success of adult and pediatric cochlear implant (CI) recipients. STUDY DESIGN: Retrospective case series. SETTING: Tertiary care referral center. PATIENTS: Thirty-nine ears in 36 patients (23 adults and 13 children) received both surgeries between 1990 and 2012. INTERVENTION: CI candidates underwent SPMO to permit implantation and minimize the risks of infectious complications in the recipient ear. SPMO was performed before (69.3%), at the time of (25.6%), and after CI (5.13%). Mastoids were obliterated with fat (30.8%), muscle (66.7%), and bone pate (2.56%). MAIN OUTCOME MEASURE: Feasibility, complications, and success of SPMO and CI were assessed with standard statistical analysis and Fisher's exact test with 2-sided p values. RESULTS: Ear disease was definitively managed, and CI was successfully placed in all but one case. Complications including abscess (n = 3), subcutaneous emphysema (n = 1), ear canal granulation formation (n = 1), and electrode extrusion (n = 1) occurred in 15.4% of patients. Predisposing syndromes were present in children more often than adults (43.8% versus 13.0%, p = 0.0598). Adults more often than children had previous mastoid surgery for middle ear disease (30.4% versus 0.0%, p = 0.0288). CIs were placed under local anesthetic and sedation (n= 3) and after radiation treatment for nasopharyngeal cancer (n = 2) in adult ears. CONCLUSION: SPMO is an effective and safe procedure for definitively managing middle ear disease and implanting adult and pediatric CI candidates.

Prediction of cochlear implant performance by genetic mutation: the spiral ganglion hypothesis.

BACKGROUND: Up to 7% of patients with severe-to-profound deafness do not benefit from cochlear implantation. Given the high surgical implantation and clinical management cost of cochlear implantation (>$1 million lifetime cost), prospective identification of the worst performers would reduce unnecessary procedures and healthcare costs. Because cochlear implants bypass the membranous labyrinth but rely on the spiral ganglion for functionality, we hypothesize that cochlear implant (CI) performance is dictated in part by the anatomic location of the cochlear pathology that underlies the hearing loss. As a corollary, we hypothesize that because genetic testing can identify sites of cochlear pathology, it may be useful in predicting CI performance. METHODS: 29 adult CI recipients with idiopathic adult-onset severe-to-profound hearing loss were studied. DNA samples were subjected to solution-based sequence capture and massively parallel sequencing using the OtoSCOPE(®) platform. The cohort was divided into three CI performance groups (good, intermediate, poor) and genetic causes of deafness were correlated with audiometric data to determine whether there was a gene-specific impact on CI performance. RESULTS: The genetic cause of deafness was determined in 3/29 (10%) individuals. The two poor performers segregated mutations in TMPRSS3, a gene expressed in the spiral ganglion, while the good performer segregated mutations in LOXHD1, a gene expressed in the membranous labyrinth. Comprehensive literature review identified other good performers with mutations in membranous labyrinth-expressed genes; poor performance was associated with spiral ganglion-expressed genes. CONCLUSIONS: Our data support the underlying hypothesis that mutations in genes preferentially expressed in the spiral ganglion portend poor CI performance while mutations in genes expressed in the membranous labyrinth portend good CI performance. Although the low mutation rate in known deafness genes in this cohort likely relates to the ascertainment characteristics (postlingual hearing loss in adult CI recipients), these data suggest that genetic testing should be implemented as part of the CI evaluation to test this association prospectively.

Sequential bilateral cochlear implantation: speech perception and localization pre- and post-second cochlear implantation.

PURPOSE: In this study, the authors sought to compare speech perception and localization in subjects who wear 1 cochlear implant (unilateral CI) or 1 cochlear implant and hearing aid (CI+HA) and then receive a second cochlear implant (bilateral CI), and to evaluate the importance of the duration between implant surgeries and duration of deafness. METHOD: Nine subjects were tested on speech perception in quiet, and 13 subjects were tested on speech perception and localization in noise using an array of 8 loudspeakers. All subjects were tested with unilateral CI prior to bilateral implantation and then again with bilateral CI after at least 3 months of bilateral experience. RESULTS: No significant difference was found between bilateral CI and unilateral CI on averaged speech perception in quiet performance. A significant benefit was found for bilateral CI on averaged speech perception in noise and on localization. Nonsignificant correlations were found for duration between surgeries, duration of deafness, and duration of bilateral use. CONCLUSIONS: Improvements for speech perception and localization played in background noise were indicated for most subjects after they received their 2nd implant. The correlations should be reassessed with a larger number of subjects to appropriately evaluate the effects of duration between surgeries, duration of deafness, and duration of bilateral use.

Initial development of a spatially separated speech-in-noise and localization training program.

OBJECTIVE: This article describes the initial development of a novel approach for training hearing-impaired listeners to improve their ability to understand speech in the presence of background noise and to also improve their ability to localize sounds. DESIGN: Most people with hearing loss, even those well fit with hearing devices, still experience significant problems understanding speech in noise. Prior research suggests that at least some subjects can experience improved speech understanding with training. However, all training systems that we are aware of have one basic, critical limitation. They do not provide spatial separation of the speech and noise, therefore ignoring the potential benefits of training binaural hearing. In this paper we describe our initial experience with a home-based training system that includes spatially separated speech-in-noise and localization training. RESULTS: Throughout the development of this system patient input, training and preliminary pilot data from individuals with bilateral cochlear implants were utilized. Positive feedback from subjective reports indicated that some individuals were engaged in the treatment, and formal testing showed benefit. Feedback and practical issues resulted from the reduction of an eight-loudspeaker to a two-loudspeaker system. CONCLUSIONS: These preliminary findings suggest we have successfully developed a viable spatial hearing training system that can improve binaural hearing in noise and localization. Applications include, but are not limited to, hearing with hearing aids and cochlear implants.

Bilateral cochlear implants in infants: a new approach--Nucleus Hybrid S12 project.

OBJECTIVE: The purpose of this feasibility study was to evaluate whether the use of a shorter-length cochlear implant (10 mm) on one ear and a standard electrode (24 mm) on the contralateral ear is a viable bilateral option for children with profound bilateral sensorineural hearing loss. A secondary purpose of this study was to determine whether the ear with the shorter-length electrode performs similarly to the standard-length electrode. Our goal was to provide an option of electrical stimulation that theoretically might preserve the structures of the scala media and organ of Corti. STUDY DESIGN: The study is being conducted as a repeated-measure, single-subject experiment. SETTING: University of Iowa-Department of Otolaryngology. PATIENTS: Eight pediatric patients with profound bilateral sensorineural hearing loss between the ages of 12 and 24 months. INTERVENTIONS: Nucleus Hybrid S12 10-mm electrode and a Nucleus Freedom implant in the contralateral ear. MAIN OUTCOME MEASURES: The Infant-Toddler Meaningful Auditory Integration Scale (IT-MAIS) parent questionnaire, Early Speech Perception, Glendonald Auditory Screening Procedure word test, and Children's Vowel tests will be used to evaluate speech perception and the Minnesota Child Development Inventory and Preschool Language Scales 3 test will be used to evaluate language growth. RESULTS: Preliminary results for 8 children have been collected before and after the operation using the IT-MAIS. All 3 children showed incremental improvements in their IT-MAIS scores overtime. Early Speech Perception, Glendonald Auditory Screening Procedure word test, and Children's Vowel word perception results indicated no difference between the individual ears for the 2 children tested. Performance compared with age-matched children implanted with standard bilateral cochlear implants showed similar results to the children implanted with Nucleus Hybrid S12 10-mm electrode and a Nucleus Freedom implant in contralateral ears. CONCLUSION: The use of a shorter-length cochlear implant on one ear and a standard-length electrode on the contralateral ear might provide a viable option for bilateral cochlear implantation in children with bilateral profound sensorineural hearing loss. Further study of this patient population will be continued.

Performance over time on adults with simultaneous bilateral cochlear implants.

BACKGROUND: Maximum performance and long-term stability of bilateral cochlear implants has become an important topic because there has been increasing numbers of recipients of bilateral cochlear implants. PURPOSE: To determine the performance over time (up to 6yr) of subjects with simultaneous bilateral cochlear implants (CI+CI) on word recognition and localization. RESEARCH DESIGN: Over-time investigation of word recognition in quiet (CNC) and sound localization in quiet (Everyday Sounds Localization Test). STUDY SAMPLE: The subjects were 48 adults who simultaneously received their cochlear implants at the University of Iowa. RESULTS: For word recognition, percent correct scores continuously improved up to 1 yr postimplantation with the most benefit occurring within the first month of implantation. In observing up to 72 mo, the averaged scores reached to the plateau of about 63% correct in CNC after 2 yr (N = 31). But, when we followed 17 subjects who have complete data set between 12 mo and 48+ months, word recognition scores were significantly different from 12 mo to 48 + months, which implies binaural advantages need more time to be developed. Localization test results suggested that the root mean square (RMS) error scores continuously improved up to 1 yr postimplantation with most benefits occurring within the first 3 mo. After 2 yr, the averaged scores reached to the plateau of about 20 degrees RMS error (N = 27). When we followed 10 subjects who have complete data set between 12 mo and 48+ months, localization scores were not improved from 12 mo to 48+ months. There were large individual differences in performance over time. CONCLUSIONS: In general, substantial benefits in both word recognition and localization were found over the first 1-12 mo postimplantation for subjects who received simultaneous bilateral cochlear implants. These benefits were maintained over time up to 6yr postimplantation.