Audiological Performance Research Articles

Common cavity and custom-made electrodes: Speech perception and audiological performance of children with common cavity implanted with a custom-made MED-EL electrode

ObjectiveFew studies exist on children with common cavity, fewer still on their long-term audiological development after having received a cochlear implant. Our goal was to observe and report the long-term audiological progress of children with common cavity who were implanted with a custom-made electrode. MethodsIn this longitudinal, multi-center study, 19 children were implanted with a MED-EL custom-made electrode via either single slit cochleostomy or double posterior labyrinthotomy. We observed their audiological development with a test battery consisting of Categories of Auditory Performance (CAP), Speech Intelligibility Rating (SIR), and Ling 6-Sounds tests. We tested the children 1 month prior to the surgery; at first fitting; at 1, 3, 6, 12, and 18 months post first-fitting; at 2 years after first-fitting; and, whenever possible, at 3, 4, and 5 years after first-fitting. ResultsChildren with common cavity tend to steadily and significantly improve their audiological skills over time. This development may, however, be highly individual; probably in part due to relatively high levels of additional needs. Parents should be counseled to establish realistic post-implantation expectations. Surgically, contrary to our expectations, we cannot confirm that double posterior labyrinthotomy reduces intracochlear electrode movement or that the MED-EL custom electrode leads to fewer incidences of intra- or post-implantation complications. ConclusionsCochlear implantation is a safe and effective treatment option in children with common cavity. The majority of children with CC derive significant audiological benefit from implantation. Intra- and post-surgical complications, while serious, and be dealt with effectively in most cases.

Audiologic Performance After Cochlear Implantation in Children With X-Linked Deafness

To compare audiologic performances of cochlear implantation (CI) in children with X-linked deafness with those of CI in age- and sex-matched children with normal cochleae. We identified 4 patients with X-linked deafness and selected 10 age- and sex-matched deaf patients with normal cochleae between April 1999 and April 2012. Auditory brainstem responses, Categories of Auditory Performance (CAP), and Meaningful Auditory Integration Scale (MAIS). The ages of patients with X-linked deafness at the time of implantation ranged between 1.3 and 13.6 years, with a mean age of 5.3 years. All patients were male subjects and showed severe-to-profound hearing loss. Patient 1 lacked ABR in both ears. Patients 2, 3, and 4 showed ABR in the contralateral ear, at 70, 70, and 90 dB nHL, respectively. All 4 patients had bilateral X-linked cochlear anomaly and experienced cerebrospinal fluid (CSF) gushers. Straight electrodes were used in Patients 1 and 3, with perimodiolar electrodes used in the others. Patients 2 and 3, who were about the same age, had CAP scores of 6 or more at 18 months after activation of the implant despite the use of different electrode arrays. There were no statistically significant differences in MAIS and CAP scores between each patient with X-linked deafness and the control group. The audiologic performances of patient with X-linked deafness after CI are comparable to those of patients with normal inner ear structure after CI.

Cochlear implantation in children with "CHARGE syndrome": surgical options and outcomes

CHARGE syndrome is a rare, polymalformative disease, representing one of the major causes of associated blindness and deafness. Bilateral, severe-profound, sensorineural hearing loss is common in CHARGE children. Aim of this study is to present our results in children with "CHARGE syndrome" submitted to cochlear implantation (CI). The frequency of anatomic anomalies, possible variations in the surgical technique of CI, and the audiological/rehabilitative benefits attained in our patients are reported. we submitted 5 children affected by CHARGE syndrome with profound, bilateral, sensorineural hearing loss to CI. Otoacoustic emissions, auditory brainstem response, acoustic impedance testing, cranial computed tomography and magnetic resonance were carried out preoperatively in all children. CI was performed using the mastoidotomy-posterior tympanotomy approach in two cases, and the suprameatal approach in three children. Infant toddler-meaningful auditory integration scale was used to evaluate kid's audiological performance before and after CI. Intra-operatory findings and postsurgical complications were evaluated. Among our patients, intraoperative anatomical malformations were cochlear hypoplasia (100 %), ossicles malformations (100 %), semicircular canals aplasia (100 %), oval window atresia (60 %), round window atresia (40 %), widening of the aqueduct of the vestibule (20 %), and aberrant course of the facial nerve (20 %). No intra- or postoperative complication was recorded in relation to implant positioning. After a follow-up ranging from 1 to 4.5 years, only 2/5 patients used oral language as the sole mean of communication, 1 started utilizing oral language as the main mean of communication, while 2 patients did not develop any linguistic ability. In conclusion, CI in patients with CHARGE association is feasible and, despite results variability, it should be carried out in CHARGE children with severe hearing loss as soon as possible. Although the selection of a specific surgical technique does not seem to influence the audiological outcome, the suprameatal access is valuable when important surgical landmarks (i.e. lateral semicircular canal and incus) are absent.

The effects of cochlear implantation on quality of life in the elderly

The purpose of this study was to evaluate the benefits of unilateral cochlear implant (CI) in patients over 60 on speech perception and quality of life, comparing the results obtained with a control group of younger CI recipients. Twenty CI users (mean age 72 years), postlingually deafened, were included in this study. Audiological performance was evaluated using bisyllabic words and sentences recognition tests in a quiet and a noise environment. Moreover, we administered two questionnaires to evaluate the health status (SF-36), CI-related effects on daily activities and personal satisfaction (Questionnaire for self-evaluation of CI benefit with SADL scale modification). Performance measures of the geriatric population showed a significant benefit on speech recognition tests compared to pre-implantation condition, even if younger CI users scored significantly better in both bisyllabic words and sentences recognition test. All study patients reported being able to have a normal conversation with an acquaintance. No significant difference was found between the study and control group in physical and mental health status, conversation with an outsider, use of TV and phone. A significant difference (p < 0.05) was noticed, instead, between elderly and younger adult patients about the overall satisfaction derived from CI. Our findings confirm the indisputable utility of CI and provide evidence that elderly patients derive a substantial benefit from it on quality of life, as demonstrated by health status, success in the common activities of daily living and perceived satisfaction after this procedure.

Can otoplasty impact hearing? A prospective randomized controlled study examining the effects of pinna position on speech reception and intelligibility.

ObjectivesOtoplasty is a commonly performed surgical procedure that restores the ideal position of the pinna. Although the pinna is a well-recognized component of the auditory apparatus, no studies have assessed the audiological effects of this procedure. We sought to quantify the impact of pinna repositioning on speech intelligibility and reception.MethodsEighteen adults with normal hearing and pinnae were recruited and the pinna positions were randomized in each participant. Intracanal acoustical analysis was performed to calculate the Speech Intelligibility Index (SII). Hearing In Noise Test (HINT) with two azimuth speaker arrangement was also performed. The outcome measures were compared using paired t-tests for both pinna positions.ResultsThe SII significantly improved with the pinna in forward position (49.3 vs. 45.8, p<0.001). HINT thresholds also improved with the pinna forward (-6.43dB vs. -5.08dB, p=0.0003).ConclusionsPinna position affects audiological performance, in both speech intelligibility and speech reception in noise. These are novel findings that may impact the informed consent process and decision to treat for patients undergoing otoplasty.

Cochlear implant failures: lessons learned from a UK centre

To review our experience of cochlear implant failure and subsequent revision surgery, and to illustrate the experience we have gained by presenting a series of lessons learned. A combined retrospective and prospective study of revision surgery in a UK regional cochlear implant centre. Of the 746 cochlear implantations undertaken, 33 (4.7 per cent of adults and 4.1 per cent of children) had a registered failure requiring re-implantation. The mean time to device failure was 60 months in adults and 35 months in children. Causes of cochlear implant failure were medical (n = 11), electrode displacement (n = 2), 'hard device failure' (n = 15) and 'soft device failure' (n = 5). Chronic suppurative otitis media and post-auricular mastoid abscess were the commonest causes of medical failure. There was one case of electrode array displacement as a direct result of skin flap revision surgery. In 80 per cent of cases, audiological performances were stable or improved following re-implantation. As the number of cochlear implants increase and patients outlive the lifespan of their devices, we will face a growing number of revision procedures. Audiologists and otologists should be competent in diagnosing and managing device failure and medical complications requiring cochlear re-implantation.

An underestimated issue: unsuspected decrease of sound processor microphone sensitivity, technical, and clinical evaluation

ObjectiveTo describe the rate of occurrence of unsuspected decrease in sensitivity of the sound processor microphone and to evaluate its effect on the patient's audiological performance in terms of reduction in speech recognition scores.DesignSpeech processor microphones were tested by connecting the speech processor acoustic monitor circuit to a hearing aid analyzer. The response curves were compared with those obtained from fully working microphones.During a 6-month investigation period, microphone response curves were measured from a group of cochlear implant recipients who had not reported any problems. Despite the absence of any subjective problem, some microphones were found to show a loss of sensitivity. Their users, aged between 4 and 67 years, were tested both with the defective and a working microphone in order to calculate the correlation between the degree of microphone failure and the decline in audiological performance.To quantify the effect of microphone failure, patients’ speech recognition skills were measured by live voice connected discourse tracking series administered in different conditions and by recorded sentences lists.ResultsA total of 120 apparently fully functioning sound processors were tested in the investigation: 33 (27.5%) were affected by a subjectively unreported sensitivity decrease. Speech-tracking scores correlated significantly with the loss of microphone sensitivity in all test conditions (r = 0.69–0.77, P < 0.05). A high degree of correlation was also found for speech audiometry tests (r = 0.70–0.73, P < 0.05). Microphone sensitivity loss affected speech recognition skills, especially without lip reading and in the presence of background noise.ConclusionThe results indicate that any reduction in sound processor microphone sensitivity causes a degree of hearing decline that negatively affects the cochlear recipient's clinical performance. Microphone faults are often unreported events, and their occurrence rate is underestimated. To establish that the microphone is providing correct input to the speech processor a standard control procedure, including technical and clinical checks, is needed in clinical practice.

Assessment of Electrode Placement and Audiological Outcomes in Bilateral Cochlear Implantation

The goal of this study was to use highly accurate nonrigid algorithms to locate the position of cochlear implant (CI) electrodes and correlate this with audiological performance. After obtaining institutional review board approval, adult patients who had bilateral CIs were identified, and those with preoperative temporal bone computed tomographic scans were asked to return for a postintervention computed tomography. Sixteen adult patients agreed. Demographics, cause of deafness, length of auditory deprivation, and audiological performance were recorded. Using a nonrigid model of the shape variations of intracochlear anatomy, the location of the basilar membrane was specified in relationship to the electrode array. The number of electrodes within each compartment of the cochlea was correlated with hearing in noise and consonant-noun-consonant scores for the known confounding variable: length of deafness. Mann-Whitney U tests of differences were used to compare the hearing performance resulting from implants completely in the scala tympani (ST) versus those not completely in the ST. Of all implants, 62.5% were fully inserted in the ST; 34.4% were partially inserted into the ST and 3.1% was fully inserted in the scala vestibuli. Controlling for the known contributing variable of length of auditory deprivation, our results show that the location of electrodes in relationship to the scala is not predictive of audiological performance. We have assessed electrode placement and correlated it with audiological outcome. The presence of the electrodes solely in the ST was not predictive of outcome. We estimate that it would take analyzing data of thousands of CI patients before any valid correlations can be made.

Cochlear implantation in the congenitally malformed ear

Approximately 20%-35% of patients with profound congenital sensorineural hearing loss have radiographic evidence of anatomic inner ear abnormalities. 1 Jackler R.K. Luxford W.M. House W.F. Congenital malformations of the inner ear: A classification based on embryogenesis. Laryngoscope. 1987; 97: 2-14 Crossref PubMed Scopus (622) Google Scholar , 2 Parry D.A. Booth T. Roland P.S. Advantages of magnetic resonance imaging over computed tomography in preoperative evaluation of pediatric cochlear implant candidates. Otol Neurotol. 2005; 26: 976-982 Crossref PubMed Scopus (114) Google Scholar , 3 McClay J.E. Tandy R. Grundfast K. et al. Major and minor temporal bone abnormalities in children with and without congenital sensorineural hearing loss. Arch Otolaryngol Head Neck Surg. 2002; 128: 664-671 Crossref PubMed Scopus (92) Google Scholar , 4 Papsin B.C. Cochlear implantation in children with anomalous cochleovestibular anatomy. Laryngoscope. 2005; 115: 1-26 Crossref PubMed Scopus (262) Google Scholar In the past, congenital malformations of the inner ear were considered by some to be a contraindication to cochlear implantation due to surgical concerns over electrode placement as well as expected poor audiologic performance. 5 Phelps P.D. Cochlear implants for congenital deformities. Jour Laryn Oto. 1992; 106: 967-970 Crossref Scopus (38) Google Scholar With the advent of improved imaging modalities as well as refined surgical techniques, implantation of the malformed inner ear is now performed frequently. In addition, recent studies continue to demonstrate a significant hearing benefit from cochlear implants in patients with inner ear dysplasia. 6 Buchman C.A. Copeland B.J. Yu K.K. et al. Cochlear implantation in children with congenital inner ear malformations. Laryngoscope. 2004; 114: 309-316 Crossref PubMed Scopus (117) Google Scholar , 7 Hoffman R.A. Downey L.L. Waltzman S.B. et al. Cochlear implantation in children with cochlear malformations. Am J Otol. 1997; 18: 184-187 PubMed Google Scholar These hearing results, however, tend to correlate with the severity of the inner ear malformation.

Cochlear implant surgery in patients more than seventy‐nine years old

To evaluate the surgical complications, auditory performance, and hearing handicap following cochlear implantation in patients greater than 79 years of age. Retrospective trial, tertiary referral center. The study group was comprised of 21 patients implanted after 79 years of age from 1996 through 2006 with follow-ups past their 8th decade. Pre-op evaluation consisted of pure-tone audiometry and speech discrimination scores (Hearing in Noise Test and City University of New York sentence test). The results of these tests were compared to similar tests taken post-op. A validated hearing handicap questionnaire was used to evaluate the outcome. There were no permanent medical or surgical complications. However, two patients developed exacerbations of previous comorbid conditions (i.e., urinary retention and acute delirium). Implanted patients experienced a significant improvement in audiologic performance, post-op pure tone average, and post-op speech scores (P < .001). A majority of them were able to use the phone and reported that the cochlear implant was of great benefit to them. The post-op hearing handicap inventory for the elderly demonstrated a significant decrease of hearing handicap scores. This is the first study to focus on a patient group this advanced in age. With increasing life expectancy, we should begin to stratify risk versus benefit of cochlear implantation in this age group. Cochlear implantation improved audiologic performance and the quality of life in patients older than 79 years old. There were no permanent medical or surgical complications. Chronic pain and temporary vertigo were the most common complications reported in this elderly group. Laryngoscope, 2009.

Analysis of Fifty-Six Cochlear Implant Device Failures

Objective: Our aim was to present a failure analysis after cochlear implant revision surgery in a large series of children and adults and to assess the outcome and audiologic performance. Methods: Fifty-six cochlear implant failures that occurred in 422 devices implanted between 1990 and 2007 at the Department of Otolaryngology, Head and Neck Surgery at the University of Mainz, Germany, were retrospectively analyzed. The causes of failure were reviewed evaluating the individual history, telemetric and intraoperative findings and manufacturer’s investigation reports. Results: We performed 56 surgical revisions in a series of 422 consecutive implants (overall revision rate: 13.27%). The most frequent causes for revision were hard failures (58.9%), most commonly caused by traumatic impact (37.5%), especially in the pediatric population. Soft failures were less frequent (21.4%). Surgical reimplantations, although challenging in some cases, were performed without complications and with an electrode insertion depth comparable to that at the time of the initial implantation in all patients. The average audiologic performance improved by 2.4 dB in pure-tone perception levels after reimplantation. Conclusion: The cochlear implant failure rates vary between children and adults as well as between different implant manufactures. However, cochlear reimplantation is safe with excellent and predictable results in audiologic performance.

Medidas de biossegurança em audiologia

TEMA: Biossegurança na atuação audiológica. OBJETIVO: rever as medidas de precaução-padrão na literatura para o controle de infecção na audiologia. As medidas de biossegurança sugeridas para diversos profissionais de saúde foram adaptadas para as atividades inerentes à prática audiológica no Serviço de Audiologia do Hospital das Clínicas da UFMG. CONCLUSÃO: as medidas de precaução-padrão apresentadas podem ser consideradas e viabilizadas nas diversas instituições, hospitais ou clínicas, nas quais a atuação fonoaudiológica é cada vez mais presente e, por conseguinte, impele medidas de precauções específicas à natureza dos exames audiológicos.

Combined Analysis of Audiologic Performance and the Plasma Biomarker Stromal Cell-Derived Factor 1a in Type 2 Diabetic Patients

This study presents a potentially novel method of screening for pathogenetic factors in diabetic audiopathy by comparing the absolute plasma concentration of a microangiopathy biomarker, stromal cell-derived factor 1a (SDF-1a), with frequency-specific audiometric results. Impaired hearing function in diabetic patients has, to date, remained a controversial and poorly understood theme with sparse clinical data. This is in contrast to more established components of the disease such as diabetic retinopathy, where diabetic microangiopathy is thought to be of pathogenetic relevance, and specific molecules such as SDF-1a have been assigned a relevant role. Out patient clinic, Vienna General Hospital, Medical University of Vienna. 18 Type 2 diabetic patients and 18 nondiabetic controls. Pure-tone audiometry and Freyburger number tests were used to evaluate hearing function. Blood plasma values of SDF-1a were analyzed using an enzyme-linked immunosorbent assay. Statistical comparison of functional audiometric data and the absolute SDF-1a values was performed for all frequencies. A significantly higher plasma SDF-1a concentration (p < 0.005) in Type 2 diabetic patients, who also presented with higher pure-tone audiometry thresholds compared with nondiabetic subjects, was noted. Furthermore, an association between SDF-1a and audiometric performance, body mass index, and duration of diabetes was observed. We hypothesize that diabetic microangiopathy and its biomarker SDF-1a should be considered as potential pathogenetic factors for altered diabetic hearing, warranting further investigation.

Performance and QOL after Geriatric Cochlear Implantation

Objective To assess audiologic performance and quality of life in geriatric cochlear implantation patients and to determine whether comorbid medical conditions, etiology, and duration of hearing loss impact audiologic and quality of life outcomes. Methods Geriatric patients who underwent cochlear implantation between 1990 and 2006 were evaluated. Inclusion criteria were 55 years of age or older at time of implantation and post-lingual hearing loss. Patients with primary language other than English were excluded. 49 cochlear implant recipients were identified. A group of younger implanted patients was used as a control. All patients completed standardized audiologic tests including the Hearing In Noise Test. Validated surveys, including the Glasgow Benefit Inventory and the Hearing Handicap Inventory for the Elderly, were used to assess quality of life. Results The mean age at implantation was 69.5 (range 58–85) and the average time interval from the implantation to the completion of the surveys was 73.2 months (6 to 229). Identified comorbid conditions included hypertension, diabetes, and malignancies, among others. Audiologic performance and quality of life scores between the two groups were similar. In the geriatric group there was no difference in patient satisfaction between subgroups with 0–1, 2–3 or &gt; 3 comorbid conditions. Conclusions Our results suggest that the audiologic performance and quality of life scores between the older and younger age groups are similar. In the geriatric group associated comorbidities did not interfere with patient satisfaction as assessed by survey instruments.

Benefit of the Vibrant Soundbridge Device in Patients Implanted For 5 to 8 Years

To assess audiological performance, satisfaction rate, and side effects of 100 patients who have been using the middle ear implant Vibrant Soundbridge (VSB) for 5 to 8 yr when compared with data collected from 3 to 18 mo postsurgery. Audiological testing and subjective evaluation using self-assessment scales were performed in 77 out of the 100 patients using the VSB for 5 to 8 years. The results were compared to data collected 3 months (audiological testing) and 18 months (self-assessment scales) after surgery. Twenty-three patients have not been evaluated for different reported reasons. Pure-tone hearing thresholds decreased similarly in both implanted and contralateral ears. The satisfaction ratings and the functional gain provided by the VSB remained stable. Speech comprehension in quiet conditions without the VSB decreased from 56 to 37% in 5 to 8 yr, but an 81% score was achieved with the VSB. This study demonstrates that the performance of the VSB does not deteriorate for more than 5 yr, without adverse effect. These results confirm the safety and the effectiveness of the VSB with a long-term follow-up.

The impact of cochlear implantation on quality of life: The role of audiologic performance and variables

The purpose of this study was to assess the impact of cochlear implantation (CI) on health-related quality of life (HRQOL), to correlate the results with audiologic performance, and to analyze the influence of variables that possibly affect the CI outcome. A retrospective study. Fifty-six adult CI users were evaluated by two HRQOL-questionnaires (the Nijmegen Cochlear Implant Questionnaire [NCIQ] and the Medical Outcome Study Short-Form 36 [SF-36]) and speech-perception tests (Freiburger monosyllable and Hochmair, Schulz, Moser (HSM) sentence test). The NCIQ showed significant improvements in the total score and in all subdomains after CI. The NCIQ total score and the advanced sound-perception and speech-production score correlated significantly with speech test results. Significant inverse relationships were noted between speech test results and duration of deafness. Significant associations were found between time since CI, NCIQ total score, and speech test results. The NCIQ was able to detect significant effects of CI on HRQOL and correlated with audiologic measures, supporting its use as a measurement tool in CI.

Audiological performance in cochlear implanted patients deafened by meningitis depending on duration of deafness

The objective of our study was to evaluate audiological outcome in cochlear implanted children deafened by meningitis and its correlation with duration of deafness from meningitis in a retrospective clinical study at an academic tertiary referral center. Sixty patients profoundly deafened by meningitis were evaluated. Two groups of children depending on duration of deafness--group 1 defined by duration of deafness less than 6 months and group 2 defined by duration of deafness over 6 months were evaluated. The control group A (duration of deafness <6 months) and group B (duration of deafness >6 months) with similar demographics data and a non-meningitis-related cause of deafness were evaluated. Patient history, cochlear implantation and audiological findings (MAIS, MUSS and open set tests questionnaire) were investigated. Standardized diagnostic and therapeutic procedure was performed in all patients. Our results showed better auditory performance and language control in children implanted within 6 months after meningitis. Over the period of 36 months group 2 was able to catch up with the group 1 in the MUSS and MAIS tests. However, the results of the common phrases test remain significantly better in group 1 over this time period (P=0.0188). In case of meningitis, audiological and radiological assessment should be performed within 4 weeks after the onset of disease. We see a clear indication for immediate implantation in patients with profound SNHL caused by meningitis. The aim should be bilateral implantation in this population to achieve the best possible performance by implantation before obliteration occurs. Premeningetic auditory experience is an important advantage which should be used. Frequent bilateral and sometimes late obliteration should be taken into consideration in the decision-making process as well.

Cochlear Reimplantation: Causes of Failure, Outcomes, and Audiologic Performance

To review Quebec's experience with cochlear reimplantation in adults and children and describe failure rates, causes of revision, surgical findings, and the impact of reimplantation on audiologic performances. Retrospective analysis of all 45 cochlear implant revision surgeries (43 reimplantations) performed on 16 adults and 25 children at the Centre Hospitalier Universitaire de Québec (Hôtel-Dieu de Québec) in Quebec City, between 1987 and 2005. : Data on patient demographics, failure sources including review of manufacturer's investigation reports, surgical findings, and outcomes (electrode insertion, complications, and audiologic performances). Mean length of device use before explantation was 5.5 years and ranged from 3 months to 17 years. Explantation was related to documented hard failure (53.3%), traumatic device failure (13.3%, only in children), extrusion of electrode array or scalp flap infection (13.3%), a decrease in performance or soft failure (11.1%), intratemporal pathology (6.7%), and a perilymphatic fistula (2.2%). Overall revision rates of 8.0% and 5.4% were obtained for children and adults, respectively. Total device failure rates of 6.2% in children and 3.3% in adults were calculated. Failure rates decreased with each new generation of Nucleus devices. Perioperative complications were uncommon. A moderate amount of fibrosis was found in the cochlea lumen, and sometimes osteoneogenesis made the reinsertion challenging. Electrode reinsertion depth was mostly comparable with the initial surgery. Speech perception abilities were maintained after reimplantation. Management of implant failures, including revision surgeries, is becoming an increasingly important part of cochlear implant program activity. It appears more commonly in children because of trauma. Medical and audiologic outcomes are generally excellent. Revision implantation appears to be a safe and effective procedure.

Cochlear Implant Channel Separation and Its Influence on Speech Perception – Implications for a New Electrode Design

There are a variety of factors which can influence cochlear implantation outcome. Channel interaction is one of the variables responsible for audiological performance deterioration in multichannel implants. Electrode design is – among others – one way to decrease the incidence of channel interaction. At present, electrodes differ in overall length, diameter, contact design and distribution, but none of the electrodes available have a distinct variability in the amount of space between contacts across the length of the electrode. The aim of this study was to investigate whether a new electrode design featuring larger contact spacing in the apical part of deeply inserted electrodes would lead to an increase in speech perception. Eighteen postlingually deafened patients fitted with MedEl Combi 40+ or MedEl Pulsar cochlear implants using the MedEl implementation of continuous interleaved sampling participated in this study. Patients were tested in 6 conditions, in which the channel spacing and distribution of electrode contacts in each patient were artificially varied by activating or deactivating different channels. Performance was tested immediately after each change in setup with a monosyllable and sentence test (Hochmaier, Schultz and Moser). Our results showed that the condition with the highest distance between contacts in the apical part (up to 6.4 mm instead of 2.4 mm) is the most effective for the matched map condition: the results improved statistically significantly for the sentence test from 72% in the standard 12-channel condition to 83.2% and from 40.8 to 50% for the monosyllable test. Based on these findings, we present a new electrode design which can help achieve further increases in speech perception with cochlear implants.

Audiological performance after cochlear implantation: a 2-year follow-up in children with inner ear malformations

Conclusions: Open-set speech perception in children with an inner ear malformation is equal to that of other congenitally deaf children after an average of 2 years follow-up. Objective: To analyze audiological performance after cochlear implantation in a sample of children with radiographically detectable malformations of the inner ear compared to performance in prelingually deafened children at large. Materials and methods: Nine children with osseous inner ear malformations were compared to 22 congenitally deaf children, all of whom underwent cochlear implantation. All subjects were tested on their electrical evoked compound action potential. Speech perception tests were performed using the monosyllabic trochee polysyllabic test without visual support and the open-set monosyllabic wordlist. Results: In all, 20% of the congenitally deaf children in our center study have inner ear abnormalities. Inner ear malformations were limited to incomplete partition of the cochlea; none of the subjects had common cavity malformations. Electrical compound action potentials were successfully recorded in both groups intraoperatively. Speech perception tests on open-set speech yielded an average of 48.8% (SD 21.2%) in the group of children with inner ear malformations vs 54.5% (SD 21.1%) in congenitally deaf children. In four of nine cases with an inner ear malformation we encountered a minor CSF leak.