Stages of Emotional Experience of Parents of Children with Cochlear Implantation (CI)

Rehabilitation is a set of measures aimed at compensating or fully restoring the functions of the patient impaired by the disease. In the rehabilitation of children with a cochlear implant, a comprehensive, systematic approach is essential in the work of doctors, teachers, sign language teachers, psychologists, and families. Rehabilitation and social adaptation of children with a cochlear implant depend not only on specialists but also on the ability of parents to help the child organize educational activities in an optimistic mood and the ability to provide emotional support. This means that the role of parents in the way to successful rehabilitation is high, and therefore this topic is especially relevant today. .

The role of cochlear implantation in alleviating Tumarkin drop attacks of Meniere's disease;a case report

Ménière’s disease(MD)patients may suffer episodes of sudden falls,named Tu markin drop attacks(DAs).This fall occurs abruptly and without warning or loss of consciousness.DAs usually aggravate the clinical picture of MD and are challenging to manage.The present report describes a case treated by cochlear implantation(CI)due to concomitant deafness and offers some clinical considerations for this condition.A male patient aged 48 years with a 10-year history of definite bilateral MD had profound SNHL on the right and severe SNHL on the left side.He suffered from intermittent attacks of vertigo,ear fullness,and tinnitus and,in the last year,had developed DAs and experienced 14 episodes in the previous six months.The preoperative category of acoustic performance was 3.The Dizziness Handicap Inventory(DHI)questionnaire showed a total score of 46,which indicated a moderate degree of disability.A CI was planned for the right side.The patient did not report any further DAs episode for two years since then.The postoperative category of acoustic performance became 11,and the postoperative DHI questionnaire showed a decrease in the total score(from 46 to 19),which indicated a mild disability.Unilateral CI effectively alleviated the DAs associated with bilateral MD.Our report proposes a new modality for managing vertiginous symptoms in cases of MD with hearing loss without the need for more aggressive surgical interventions with the need for clinical trials to confirm our results.

Comparing accuracy of cochlear measurements on magnetic resonance imaging and computed tomography:A step towards radiation-free cochlear implantation

Objective:Computed Tomography(CT)and Magnetic Resonance Imaging(MRI)are commonly employed in pre-operative evaluation for cochlear implant surgery.However,with a decrease in the age of implantation,even minor radiation exposure can cause detrimental effects on children over their lifetime.The current study compares different cochlear measurements from CT and MRI scans and evaluates the feasibility of using only an MRI scan for radiological evaluation before cochlear implantation.Methods:A longitudinal observational study was conducted on 94 ears/47 children,employing CT and MRI scans.The CT and MRI scan measurements include,A value,B value,Cochlear duct length(CDL),twoturn cochlear length,alpha and beta angles to look for cochlear orientation.Cochlear nerve diameter was measured using MRI.The values were compared.Results:The mean difference between measurements from CT and MRI scans for A value,B value,CDL,and two-turn cochlear length values was 0.567±0.413 mm,0.406±0.368 mm,2.365±1.675 mm,and 2.063±1.477 mm respectively without any significant difference.The alpha and beta angle measures were comparable,with no statistically significant difference.Conclusion:The study suggests that MRI scans can be the only radiological investigation needed with no radiation risk and reduces the cost of cochlear implant program in the paediatric population.There is no significant difference between the measurements obtained from CT and MRI scans.However,observed discrepancies in cochlear measurements across different populations require regionally or race-specific standardized values to ensure accurate diagnosis and precision in cochlear implant surgery.This aspect must be addressed to ensure positive outcomes for patients.

Barriers to Early Pediatric Cochlear Implantation in Kenya

Background: Cochlear implantation is the best management option for children with profound hearing loss and has received no benefit from hearing aids. Early implantation for these children is associated with good speech and language outcomes. Objectives: To determine the barriers to early pediatric cochlear implantation. Methodology: A qualitative cross-sectional study was conducted at Hearing Implants Centre in Nairobi Kenya from August 2022 to February 2023. The target population was 40 children who had undergone cochlear implantation under the auspices of Cochlear Implant Group of Kenya but data was only collected from 30 of them. The remaining were ruled out because 3 were unreachable over the phone, 5 refused to participate and 2 did not meet the inclusion criteria. Results: Patient file reviews and parental telephone interviews were conducted to collect information and analyzed using Microsoft excel and presented using graphs, tables and pie charts. The analysis of the gender showed 46.67% were male and 53.33% were female. Analysis on newborn screening showed that none had it done. The mode age of hearing loss suspicion was between the ages of 2 - 3 years. The hearing loss suspicion done was done by the mothers at 20 children the reminder being 3 by the father, 1 by a family friend, 4 by the school-teacher and 2 by the child’s grandmother. A total of 17 participants noted a delayed in speech and language, 9 noted that the child did not respond to loud sounds, 4 noted that the children did not turn when called. Once hearing loss was identified, 73% saw the ENT, 17% saw a pediatrician, 7% went to see an Audiologist, and 3% saw a speech therapist. The mode age at diagnosis was 1.5 years. The mode age at implantation was 5 years. The mode time from diagnosis was 2 years. Conclusions: This study sought to investigate the barriers to pediatric cochlear implantation in Kenya. From the results it was determined that factors such as lack of newborn screening, high cost of cochlear implantation, lack of awareness have led to late cochlear implantation.

Preliminary Results of Cochlear Implantation in Underdeveloped Countries: The Experience of Cameroon

Introduction: Deafness, is the most common neurosensory deficit in humans. The origins can be diverse: congenital or acquired and sometimes of an etiology that is difficult to specify. The main risk is social exclusion. The advent of cochlear implants is a solution of choice for severe to profound sensorineural hearing loss. This innovative therapeutic modality is new to Cameroon, so we proposed to evaluate the preliminary results of cochlear implantation at the General Hospitals of Yaoundé and Douala, by addressing the epidemiological, clinical and paraclinical, surgical, and prosthetic aspects. Methodology: We conducted a descriptive and prospective cross-sectional study over a period of two years and eight months, from January 2019 to 31 August 2021. The study sites were: the general hospitals of Yaounde and Douala, as well as the private practices of speech therapists in the said cities. We collected socio-demographic, clinical, paraclinical variables and data on surgical, prosthetic and speech therapy management which were processed. Results: We recruited 15 cochlear implant patients, one adult and 14 children. The sex ratio was 1.14 in favour of girls, the average age of the child population was 4.9 years and one subject was 57 years old. These children were mostly in school (85.7%) and mostly (86.7%) living in urban areas. The average period of sound deprivation was 3.9 years. The deafness of the children was 100% prelingual and the acquired cause was evoked in front of the risk factors (prematurity, low birth weight, neonatal asphyxia, jaundice, meningitis, neuromalaria) for 57.7% of them. The adult deafness was postlingual and post-traumatic. The associated clinical conditions found in 4 (26.8%) of the patients were an ocular refraction disorder, a chronic otitis media sequelae, cerebral palsy and minor head trauma injuries. There was no syndromic or malformative picture. The deafness was bilateral in all cases, asymmetric in 22.2% of cases and severe to profound sensorineural. The threshold of the deafness was deep in 78.6% of cases, with a more marked involvement on the right. Imaging studies (MRI and CT scans of the cranium, brain and rock) carried out in our series showed abnormalities in 4 (26.7%) of the children, but none of these abnormalities were an absolute contraindication to implantation. The surgical management was done with oticon® Neuro ZTI implants. Implantations were unilateral and mostly right, with one case of stenosis of the round window recess observed. The postoperative course was simple for 92.8% of patients. One case of superinfection of the surgical wound. The activations were performed within four to five weeks after surgery and the implant was functional in fourteen patients and dysfunction was observed in one patient. Conclusion: The cochlear implant is an effective solution in the fight against severe to profound sensorineural deafness. The diffusion of this therapeutic tool in our environment is still hampered by the youth of the teams, the lack of equipment and the insufficient financial means.

Double challenge:cochlear implantation in the only hearing ear with progressive hearing loss following meningitis and vestibular dysfunction after implantation

Objective:Vestibular dysfunction associated with cochlear implantation is rare.It is usually seen in patients with otosclerosis due to spread of electrical activity throughout the demineralized bone.A 17-year old female with progressive hearing loss 2 years after meningitis and vestibular dysfunction in the implanted ear is presented in this study.Findings:The patient had mild hearing loss in the right ear and total hearing loss on the left side because of complete ossification of the cochlea following meningitis.She had to have cochlear implantation in the right ear because of progression of hearing loss.She had successful implantation but she experienced vestibular dysfunction following activation of cochlear electrodes.Closure of two electrodes caused disruption of auditory programming.Then the patient was subjected to long term vestibular rehabilitation program.Conclusion:Timing for implantation before the completion of cochlear ossification is crucial not to miss the chance for hearing restoration.However,difficulties in hearing rehabilitation due to extensive ossification can be doubled by vestibular problems triggered by stimulation of the vestibular nerve by cochlear electrodes.Attempts to reduce the balance problem will complicate auditory programming.Vestibular rehabilitation for long term helps to carry on hearing progress.

Molecular mechanisms and roles of inflammatory responses on low-frequency residual hearing after cochlear implantation

Preservation of low-frequency residual hearing is very important for combined electro-acoustic stimulation after cochlear implantation.However,in clinical practice,loss of low-frequency residual hearing often occurs after cochlear implantation and its mechanisms remain unclear.Factors affecting lowfrequency residual hearing after cochlear implantation are one of the hot spots in current research.Inflammation induced by injury associated with cochlear implantation is deemed to be significant,as it may give rise to low-frequency residual hearing loss by interfering with the blood labyrinth barrier and neural synapses.Pathological changes along the pathway for low-frequency auditory signals transmission may include latent factors such as damage to neuroepithelial structures,synapses,stria vascularis and other ultrastructures.In this review,current research on mechanisms of low-frequency residual hearing loss after cochlear implantation and possible roles of inflammatory responses are summarized.

Cochlear implantation in a child with auditory neuropathy spectrum disorder

Objective To report outcomes of cochlear implantation (CI) in a child with auditory neuropathy spectrum disorder (ANSD) and to provide preliminary clinical evidence of the efficacy of CI in ANSD patients.Methods A 4-year-old boy with diagnosed auditory neuropathy spectrum disorder (ANSD) received implantation of a Nucleus CI24R after an unsatisfactory trial of amplification.Post-implantation performance in both hearing sensitivity and speech recognition was assessed in different sessions.Aided hearing thresholds were tested by behavioral audiometry.Mandarin Early Speech Perception Test (MESP),Meaningful Auditory Integration Scale (MAIS),category of auditory performance (CAP) and Speech Intelligibility Rating (SIR) were used to assess the benefits in auditory skills or speech recognition the boy obtained from CI.The tests were administered before surgery and at 3 months and 7 months after opening.Results The boy demonstrated improved auditory sensitivity by using CI.Concerning speech recognition and communication,both speech audiometry and questionnaires showed an obvious benefit from CI.Conclusions CI has worked efficiently in this ANSD boy.But because of limited understanding of ANSD and rehabilitation effect by cochlear implantation in this condition,the clinical decision to implant should be cautious and only after a thorough evaluation.Meanwhile,well controlled and long term studies are needed to confirm the efficacy of cochlear implantation in patients with ANSD.

Improvements to the retractor and muscle flap design for minimally invasive cochlear implantation

Objective: The aim of this study was to improve muscle flaps and to evaluate surgical outcomes with the use of a novel specialized retractor, which is a surgical instrument used to locate and shape a bony seat for minimally invasive cochlear implantation.Methods: 50 patients aged 1 e75 years with sensorineural hearing loss who required cochlear implantation were recruited. A small incision(<3 cm) was made, and the novel specialized retractor was used in the study group during cochlear implantation. The incision length, surgical outcomes and operative time were recorded and analyzed.Results: The incision length, total operative time and drilling bony time were shorter in the study group than in the control group(P < 0.05, respectively). All patients recovered well after the surgery without any severe complications.Conclusion: The use of a novel specialized retractor standardized the surgical processes of cochlear implantation. The retractor helped locate and control the size of the bony well during bone drilling. The tool reduced the technical difficulty and improved the efficacy of this minimally invasive operation.

Safety and outcomes of cochlear implantation in the elderly:A review of recent literature

Global demographic changes related to longevity are leading to increasing numbers of the elderly, for whom hearing loss is a significant cause of morbidity and disability. Once met with reticence, severely hearing impaired older adults are increasingly being considered for cochlear implantation (CI). Significant data indicate that CI in the elderly population is safe, well-tolerated, and effective. Risks from CI surgery and anesthesia are low and generally comparable to rates in other age groups. Outcomes studies regarding CI in older adults have shown excellent improvements to speech perception, quality of life, and even cognition. Overall, currently available data suggests that advanced age should not, in itself, be considered a barrier to implantation. This review paper will highlight selected articles from recent medical literature regarding the safety and efficacy of CI in the elderly population. Copyright ? 2016, PLA General Hospital Department of Otolaryngology Head and Neck Surgery. Production and hosting by Elsevier (Singapore) Pte Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

After cochlear implantation: Complications related to flap around implants

Objective: To report complications related to flap around implants after cochlear implantation, possible causes of such complications and treatments.Methods and material: We performed a retrospective analysis of children in whom complications related to flap around implants occurred after undergoing cochlear implantation in our department from 2005 to 2016.Results: Complications among 1500 cochlear implantation(CI) recipients by the same surgeon included hematoma(n ? 20) and seroma around implants(n ? 15), of which most(n ? 10) recovered in 2 weeks after effective drainage, utility of antibiotics and pressure dressing, but 5developed flap necrosis and had to undergo contralateral re-implantation. Four patients developed abscess around implants, of whom 2 recovered after 2 weeks of drainage, gentamicin irrigation and use of antibiotics, but 2 patients ended up with flap necrosis and had to receive contralateral reimplantation.Conclusions: Immediate drainage, pressure dressing and antibiotics can be used to effectively control seroma around implants. For seroma lasting for more than two weeks without improvement, surgical drainage may be need.

Communication outcomes following cochlear implantation in a child with cystic cochleovestibular anomaly

Cochlear implantation is one of the best amongst the various management options available for children and adults with severe to profound sensorineural hearing loss.Inner ear and internal auditory canal(IAC) malformations accounts to approximately 25% of congenital sensorineural hearing loss in children.The primary goal of this report was to evaluate the communication outcomes after cochlear implantation in a child with cystic cochleovestibular anomaly(CCVA).The child was evaluated through various standardized outcome measures at regular intervals to track the progress in terms of auditory and spoken language skills.The scores on Categories of Auditory Perception(CAP),Meaningful Auditory Integration Scale(MAIS),Speech Intelligibility Rating(SIR),Meaningful Use of Speech Scale(MUSS),and listening and spoken language skills showed a significant leap in 12 months duration post implantation.The report thus highlights and correlates the significant progress in auditory and spoken language skills of the child with congenital malformations to appropriate auditory rehabilitation and intensive parental training.

Evaluation of rehabilitation outcomes after cochlear implantation in later-implanted patients with prelingual deafness

Objective:To identify the changes in the quality of life and speech recognition ability of older pre-lingual deaf patients before and after cochlear implant surgery.Methods:A total of patients with pre-linguistic deafness who underwent unilateral cochlear implant surgery at the Sun Yat-sen Memorial Hospital of Sun Yat-sen University from February 2012 to November 2018 were taken as the research object.The CAP scale,SIR scale,and Nijmegen cochlear implant scale were used to assess the patient's condition for the quality of life before and 2 years after the operation,and compared the postoperative and preoperative scores were compared.At the same time,the angel language training was adopted.The auditory rehabilitation system and the Chinese open speech perception assessment system were used to test the speech recognition rate of patients before and 2 years after implantation.Results:The quality of life of patients undergoing cochlear implant surgery improved two years after the operation.CAP,SIR scores and NCIQ sub-fields(basic voice perception,advanced voice perception,speech ability,self-confidence,activity ability,and social communication)were significantly improved compared with those preoperatively,and the speech recognitionrate score was also improved.There was a significant correlation between the quality of life and speech recognition of the test patients.Conclusion:Cochlear implantation has a significant effect on improving the quality of life and speech recognition ability of older pre-linguistic deaf patients.The correlation between quality of life and speech recognition still needs to be further explored.Therefore,-,quality of life and language recognition are the assessment of older pre-linguistic deafness.The rehabilitation effect of patients after cochlear implantation needs to be considered at the same time.

Is the clinical head impulse test helpful in cochlear implantation candidacy evaluation?

Objective:Vestibular dysfunction is a known risk of cochlear implantation(CI).However,the utility of the physical exam to screen CI candidates for vestibular dysfunction is not well-studied.The objective of this study is to evaluate the preoperative role of the clinical head impulse test(cHIT)in subjects undergoing CI surgery evaluation.Study Design Setting,and Subjects:We conducted a retrospective review of 64 adult CI candidacy cases between 2017 and 2020 at a tertiary health care center.Methods:All patients underwent audiometric testing and evaluation by the senior author.Patients with an abnormal catch-up saccade contralateral to their worse hearing ear during cHIT were referred for formal vestibular testing.Outcomes included clinical and formal vestibular results,operated ear with regard to audiometric and vestibular results,and postoperative vertigo.Results:Among all CI candidates,44%(n=28)reported preoperative disequilibrium symptoms.Overall,62%(n=40)of the cHITs were normal,33%(n=21)were abnormal,and 5%(n=3)were inconclusive.There was one patient who presented with a false positive cHIT.Among the patients who endorsed disequilibrium,43%had a positive preoperative cHIT.Fourteen percent of the subjects(n=9)without disequilibrium had an abnormal cHIT.In this cohort,bilateral vestibular impairment(71%)was more common than unilateral vestibular impairment(29%).In 3%of the cases(n=2),surgical management was revisited or altered due to cHIT findings.Conclusion:There is a high prevalence of vestibular hypofunction in the CI candidate population.Self-reported assessments of vestibular function are often not congruent with cHIT results.Clinicians should consider incorporating cHITs as part of the preoperative physical exam to potentially avoid bilateral vestibular dysfunction in a minority of patients.

Analysis of the Influence of Sound Source Position and Electrode Placement on the Stimulation Pattern of the Cochlear Implant under Noise Conditions: Optimization of Auditory Perceptual Effects

Background: Cochlear implants (CI) are widely used to restore hearing in people with severe to profound hearing loss. However, optimizing CI performance, especially in difficult listening environments with background noise, remains a major challenge. Understanding the influence of factors such as sound source position and electrode placement on CI stimulation patterns is critical to improving auditory perception. Methods: In this study, an analysis was conducted to investigate the influence of sound source position and electrode placement on CI stimulation patterns under noisy conditions. For this purpose, a special measurement setup with a CI speech processor-microphone test box was used to simulate realistic listening scenarios and measure CI performance. Results: The results show that the effectiveness of CI noise reduction systems is influenced by factors such as the position of the sound source and electrode placement. In particular, the beamforming ultra zoom mode showed significantly better noise reduction than the omnidirectional mode, especially under real listening conditions. Furthermore, differences in electrode responses indicate individual variability in the CI user experience, highlighting the importance of personalized fitting algorithms. Conclusions: The results demonstrate the importance of considering environmental factors and individual differences when optimizing CI performance. Future research efforts should focus on the development of personalized fitting algorithms and the exploration of innovative strategies, such as the integration of artificial intelligence, to improve CI functionality in different listening environments. This study contributes to our understanding of CI stimulation patterns and lays the foundation for improving auditory perception in CI users.

Minimally Invasive Cochlear Implantation Assisted by Bi-planar Device： An Exploratory Feasibility Study in vitro

Background：A single drilled tunnel from the lateral mastoid cortex to the cochlea via the facial recess is essential for minimally invasive cochlear implant surgery.This study aimed to explore the safety profile of this kind of new image-guided and bi-planar device-assisted surgery procedure in vitro.Methods：Image-guided minimally invasive cochlear implantations were performed on eight cadaveric temporal bone specimens.The main procedures were：（1） temporal bone specimens were prepared for surgery and fiducial markers were registered.（2） computed tomography （CT） scans were performed for future reference.（3） CT scan images were processed and drill path was planned to minimize cochlear damage.（4） bi-planar device-assisted drilling was performed on the specimens using the registration.（5） surgical safety was evaluated by calculating the deviation between the drill and the planned paths,and by measuring the closest distance between the drilled path and critical anatomic structures.Results：Eight cases were operated successfully to the basal turn of the cochlear with intact facial nerves （FNs）.The deviations from target points and entrance points were 0.86 mm （0.68-1.00 mm） and 0.44 mm （0.30-0.96 mm）,respectively.The angular error between the planned and the drilled trajectory was 1.74° （1.26-2.41°）.The mean distance from the edge of the drilled path to the FN and to the external canal was 0.60 mm （0.35-0.83 mm） and 1.60 mm （1.30-2.05 mm）,respectively.In five specimens,the chorda tympani nerves were well preserved.In all cases,no injury happened to auditory ossicles.Conclusions：This exploratory study demonstrated the safety of the newly developed image-guided minimally invasive cochlear implantation assisted by the bi-planar device and established the operational procedures.Further,more in vitro experiments are needed to improve the system operation and its safety.

Minimal incision access for pediatric and adult cochlear implantation

Background Cochlear implant surgery is widely practiced.Minimal incision cochlear implant surgery has been developed with the aims of reducing the impact of surgery on the patient and improving cosmesis while maintaining the low morbidity of conventional wider access approaches.This study aimed to assess the surgical technique and complication rate of minimal incision cochlear implantation （MICI） for children and adults.Methods Data for this study were obtained via a retrospective analysis.Totally 378 patients were included in the study.All patients received minimal incision cochlear implantation,using the skin protector during the process of the operation.The surgical complications of MICI were recorded in a spreadsheet format.The incidence of major and minor complication were analyzed,and appropriate treatment was provided.Results A total of 40 （10.5％） complications were noted in the study.There were 0 life-threatening,9 major,and 31 minor complications.Of the nine major complications,five were device failures,one developed infection and extrusion,and three required receiver-stimulator repositioning.Conclusions MICI is as safe as standard cochlear implantation （SCI） and affords with it other benefits.Eliminating the scalp flap avoids devascularization and minimizes the opportunity of flap infection or necrosis.Complications not related to the flap are similar to SCI.

Foreign Body Reaction After Cochlear Implantation： A Case Report

Foreign body reaction is a rare complication after cochlear implantation.When such complications do occur,they may be intractable and difficult to be cured with antibiotics or surgical revision that may lead to cochlear reimplantation finally.In this article,we presented a patient with foreign body reaction who recovered well after cochlear reimplantation and has been in good health throughout the 6 years of follow-up at regular intervals in Affiliated Eye Ear Nose and Throat Hospital of Fudan University.

Clinical evaluation of cochlear implantation in children younger than 12 months of age

Importance Cochlear implantation(CI)is an effective therapy for patients with severe to profound sensorineural hearing loss.It remains controversial whether children younger than 12 months of age should undergo CI.Objective To evaluate the safety and effectiveness of CI in children younger than 12 months of age.Methods We performed a retrospective study of clinical data of pediatric patients younger than 12 months of age who underwent CI and were followed up for 1 to 2 years.Patients’developmental levels were evaluated by the Gesell score before CI.Intraoperative and postoperative complications were recorded to evaluate the safety of CI.Auditory and speech abilities were scored by the LittlEARS®auditory questionnaire(LEAQ),categories of auditory performance(CAP),speech intelligibility rating(SIR),infant‐toddler meaningful auditory integration scale(IT‐MAIS),and meaningful use of speech scale(MUSS)at 1,2,3,6,9,and 12 months after CI.The associations between clinical characteristics before CI and postoperative scores at 1 year after CI were analyzed by the linear mixed‐effects model.Results Eighty‐nine children(47 boys and 42 girls)were included in this study(mean age at CI,9.2±1.6 months).Sixteen patients were diagnosed with cochlear malformation and 16 underwent bilateral CI.No severe complications occurred in any patients.The mean developmental quotient of the Gesell score was 78.00±10.03.The median LEAQ scores were 0,5,10,16,22,26 and 30 before and at 1,2,3,6,9,and 12 months after CI,respectively.These findings implied that the LEAQ score greatly improved in the first year after CI.The overall CAP,SIR,IT‐MAIS,and MUSS scores also increased with increasing duration after CI.No significant associations were detected between clinical characteristics(age,sex,implant number,pre‐CI Gesell score,and inner ear malformation)and LEAQ outcomes at 12 months after CI.Interpretation With increasing duration after CI,auditory and speech behavior dramatically improve in young children.Our findings indicate that CI is feasible for children younger than 12 months of age.

Cochlear implantation surgery in patients with totally ossified cochlea

The goal of cochlear implantation （CI） surgery is to make all patients with profound sensorineural hearing loss achieve satisfied postoperative performance. It will contribute to the excellent postoperative performance to insert the full length of the electrode array into the scala tympani with little trauma to the structure.