Mandarin Chinese speech recognition by pediatric cochlear implant users

Objectives

Because of difficulties associated with pediatric speech testing, most pediatric cochlear implant (CI) speech studies necessarily involve basic and simple perceptual tasks. There are relatively few studies regarding Mandarin-speaking pediatric CI users’ perception of more difficult speech materials (e.g., words and sentences produced by multiple talkers). Difficult speech materials and tests necessarily require older pediatric CI users, who may have different etiologies of hearing loss, duration of deafness, CI experience. The present study investigated how pediatric CI patient demographics influence speech recognition performance with relatively difficult test materials and methods.

Methods

In this study, open-set recognition of multi-talker (two males and two females) Mandarin Chinese disyllables and sentences were measured in 37 Mandarin-speaking pediatric CI users. Subjects were grouped according to etiology of deafness and previous acoustic hearing experience. Group 1 subjects were all congenitally deafened with little-to-no acoustic hearing experience. Group 2 subjects were not congenitally deafened and had substantial acoustic hearing experience prior to implantation. Multiple linear regression analyses were performed within each group using subject demographics such as age at implantation and age at testing.

Results

Pediatric CI performance was generally quite good. For Group 1, mean performance was 82.3% correct for disyllables and 82.8% correct for sentences. For Group 2, mean performance was 76.6% correct for disyllables and 84.4% correct for sentences. For Group 1, multiple linear regression analyses showed that age at implantation predicted disyllable recognition, and that age at implantation and age at testing predicted sentence recognition. For Group 2, neither age at implantation nor age at testing predicted disyllable or sentence recognition. Performance was significantly better with the female than with the male talkers.

Conclusions

Consistent with previous studies’ findings, early implantation provided a significant advantage for profoundly deaf children. Performance for both groups was generally quite good for the relatively difficult materials and tasks, suggesting that open-set word and sentence recognition may be useful in evaluating speech performance with older pediatric CI users. Differences in disyllable recognition between Groups 1 and 2 may reflect differences in adaptation to electric stimulation. The Group 1 subjects developed speech patterns exclusively via electric stimulation, while the Group 2 subjects adapted to electric stimulation relative to previous acoustic patterns.     

Perception of speech by prelingual pre-adolescent and adolescent cochlear implant users

Abstract

This study was undertaken to assess the speech perception benefits, 24 months after cochlear implantation (CI), in 20 young people (age at CI, 8–18.5 years) with prelingual profound hearing loss, in addition to the use of a proposed CI candidacy assessment profile. Speech perception was evaluated in terms of word and sentence perception before CI, and at six-monthly intervals for two years after CI. Before undergoing CI, all participants were tested on a pre-implantation assessment profile. Compared to the pre-CI findings, group results over 24 months post-CI demonstrated improved speech perception abilities reaching, on average, 46% for word recognition, 71.3% for sentences in quiet, and 33.6% for sentences in noise. Pre-CI profile scores correlated significantly with all speech perception results obtained 24 months after CI. Thus, despite their relatively late ages at implantation, all participants showed gradually improving performance in speech perception. The results showed a high variability in the outcomes of the participants. The pre-CI profile appeared to be useful in formulating realistic expectations of CI outcome during pre-implantation consultations, suggesting that expectations can and should be managed according to each patient's pre-implantation assessment.

Sumario

Se llevó a cabo este estudio para evaluar los beneficios en la percepción del lenguaje, 24 meses después de la implant-ación coclear (CI), en 20 personas jóvenes (edad en la CI de 8-18.5 años), con sordera prelingüística profunda, en quienes se usó un perfil propuesto de evaluación para la candidatura a la CI. La percepción del lenguaje se evaluó en términos de percepción de palabras y oraciones antes de la CI y a intervalos de seis meses, durante dos años, después de la CI. Antes de la CI todos los participantes fueron examinados con un perfil de evaluación pre-implantación. Comparados con los hallazgos pre-CI, los resultados del grupo después de 24 meses de la CI mostraron mejoría en las habilidades para la percepción del lenguaje alcanzando, en promedio, 46% para el reconocimiento de palabras, 71.3% para oraciones sin ruido y 33.6% para oraciones con ruido. Las puntuaciones en el perfil pre-CI correlacionaron significativamente con todos los resultados de percepción del lenguaje obtenidos 24 meses después de la CI. Así, a pesar de las edades de implantación relativamente tardías, todos los participantes mostraron un desempeño gradual-mente mejor en la percepción del lenguaje. Los resultados mostraron una gran variabilidad en los resultados de los participantes. El Perfil pre-CI parece ser útil para formular expectativas realistas sobre los resultados de la CI durante las consultas pre-implante, sugiriendo que las expectativas pueden y deben ser manejadas de acuerdo con las evaluaciones pre-implantación de cada paciente.     

Voice gender discrimination provides a measure of more than pitch-related perception in cochlear implant users

Abstract

Objectives: (1) To investigate whether voice gender discrimination (VGD) could be a useful indicator of the spectral and temporal processing abilities of individual cochlear implant (CI) users; (2) To examine the relationship between VGD and speech recognition with CI when comparable acoustic cues are used for both perception processes. Design: VGD was measured using two talker sets with different inter-gender fundamental frequencies (F₀), as well as different acoustic CI simulations. Vowel and consonant recognition in quiet and noise were also measured and compared with VGD performance. Study sample: Eleven postlingually deaf CI users. Results: The results showed that (1) mean VGD performance differed for different stimulus sets, (2) VGD and speech recognition performance varied among individual CI users, and (3) individual VGD performance was significantly correlated with speech recognition performance under certain conditions. Conclusions: VGD measured with selected stimulus sets might be useful for assessing not only pitch-related perception, but also spectral and temporal processing by individual CI users. In addition to improvements in spectral resolution and modulation detection, the improvement in higher modulation frequency discrimination might be particularly important for CI users in noisy environments.

Sumario

Objetivos: (1) Investigar si la discriminación de voz por género (VGD) puede ser un indicador útil de las habilidades de procesamiento espectral y temporal de usuarios de implantes cocleares (IC); (2) Examinar la relación entre VGD y el reconocimiento del lenguaje con IC, cuando se usan claves acústicas comparables para ambos procesos de percepción. Diseño: Se midió el VGD usando dos series de hablantes con diferentes frecuencias fundamentales (Fo) inter-género así como diferentes simulaciones acústicas de IC. El reconocimiento de vocales y consonantes en silencio y con ruido también se midió y comparó con el rendimiento VGD. Muestra: Once usuarios sordos de IC post-lingüísticos. Resultados: Los resultados mostraron que 1) el rendimiento promedio VGD difirió para diferentes grupos de estímulos; 2) el rendimiento para el reconocimiento de VGD y de lenguaje varió entre usuarios de IC y 3) el rendimiento individual de VGD correlacionó significativamente con el reconocimiento del lenguaje bajo ciertas condiciones. Conclusiones: El VGD medido con grupos seleccionados de estímulos puede ser útil para evaluar no solamente la percepción relacionada con la frecuencia sino también el procesamiento espectral y temporal en usuarios de IC. Además de la mejoría en la resolución espectral y en la detección de la modulación, la mejoría en la discriminación en frecuencias de alta modulación puede ser particularmente importante para los usuarios de IC en ambientes de ruido.     

Effects of residual speech and auditory deprivation on speech perception of adult cochlear implant recipients

Objective

Possible predictive factors of cochlear implant (CI) outcomes have been extensively reported in literature for different user groups such as prelingual pediatric or postlingual adult users. However, there remains unexplained outcome variability among adult CI users; therefore, research concerning these patients continues and many different variables have been reported. This study aimed at evaluating the relationship between preoperative speech reception capacity, residual hearing, duration of deafness, age of implantation, and postoperative monosyllabic word recognition scores (WRSs) in postlingual CI users.

人工耳蜗植入电极分布频带不同排列模式对语言识别能力的影响

目的通过测试电子耳蜗植入患者电极分布频带颠倒排列前后声音识别的变化,探讨电极分布频带排列模式对声音识别能力的影响。方法15名电子耳蜗植入患者,分别依次测试电极分布频带颠倒排列前后对铃声（代表高频）和鼓声（代表低频）两种不同声音的识别能力,记录并分析结果。结果在电极分布频带按低频对应蜗尖、高频对应蜗底的正常顺序排列时,均能准确识别出铃声和鼓声。在电极分布频带颠倒排列后,13名受试者将铃声和鼓声均识别为鼓声,另2名则将铃声识别为鼓声,而将鼓声识别为铃声。结论电子耳蜗电极分布频带排列模式改变可以影响电子耳蜗植入患者对声音的识别能力。     

Correlative studies of cochlear neuronal loss with speech discrimination and pure-tone thresholds

Summary Correlations were made between speech discrimination scores, pure-tone thresholds, and neuronal populations in 28 cochleae which were removed postmortem from elderly patients who had known premortem audiometric records. The predominant pathology present was loss of cochlear neurons. The capability for speech discrimination correlated directly with the innervation density of the 15- to 22-mm region (segment III) of the cochlea. Speech discrimination scores showed an inverse relationship to pure-tone thresholds in the middle frequency range of 1 kHz to 2 kHz.Supported by the National Institute of Neurlogical and Communicative Disorders and Stroke, grant no. 5 ROI NS05881     

语前聋儿童人工耳蜗植入效果的评估

目的探索语前聋儿童人工耳蜗植入效果的评估方法.方法受试者为18名接受人工耳蜗植入的语前聋儿童,耳蜗植入时平均年龄6岁.按人工耳蜗使用时间长短分为四个阶段进行评估:第一阶段18名患儿,使用人工耳蜗1～12个月;第二阶段12名,使用人工耳蜗13～24个月;第三阶段8名,使用人工耳蜗25～36个月;第四阶段6名,使用人工耳蜗在36个月以上.描述性分析,以问卷的形式了解儿童在人工耳蜗植入后声音接受、言语表达及行为等方面的变化;言语测试,进行言语识别能力和发声能力测试.结果第一阶段患儿,能够感知和辨别来自家庭和环境中的声音;第二阶段患儿,封闭项词识别率是51%,开放项词识别开始启动;第三阶段患儿,封闭项词识别率达到72%,开放项词识别率是40%,能正确发出的单词数是42%;第四阶段患儿,封闭项词识别率和开放项词识别率分别达到84%和53%,能正确发出的单词数达62%,部分患儿已有自发的口语表达.结论人工耳蜗植入对语前聋患儿的言语发育有帮助,患儿的言语能力随着人工耳蜗使用时间的推移不断进步.     

Optimizing the perception of soft speech and speech in noise with the Advanced Bionics cochlear implant system

Abstract

Objective: This study aimed to provide guidelines to optimize perception of soft speech and speech in noise for Advanced Bionics cochlear implant (CI) users. Design: Three programs differing in T-levels were created for ten subjects. Using the T-level setting that provided the lowest FM-tone, sound-field threshold levels for each subject, three additional programs were created with input dynamic range (IDR) settings of 50, 65 and 80 dB. Study sample: Subjects were postlinguistically deaf adults implanted with either the Clarion CII or 90K CI devices. Results: Sound-field threshold levels were lowest with T-levels set higher than 10% of M-levels and with the two widest IDRs. Group data revealed significantly higher scores for CNC words presented at a soft level with an IDR of 80 dB and 65 dB compared to 50 dB. Although no significant group differences were seen between the three IDRs for sentences in noise, significant individual differences were present. Conclusions: Setting Ts higher than the manufacturer's recommendation of 10% of M-levels and providing IDR options can improve overall speech perception; however, for some users, higher Ts and wider IDRs may not be appropriate. Based on the results of the study, clinical programming recommendations are provided.

Sumario

Objetivo: Este estudio buscó proporcionar pautas para optimizar la percepción del lenguaje suave y del lenguaje en ruido para usuarios del implante coclear (IC) de Advanced Bionics. Diseño: Se crearon tres programas para diez pacientes, que eran diferentes en sus niveles T. Al usar el control de nivel T que proporcionaba el tono FM más bajo, con niveles de umbral en campo libre para cada sujeto, se crearon tres programas adicionales con controles de ingreso del rango dinámico IRD de 50, 65 y 80 dB. Muestra de Estudio: Los sujetos fueron sordos adultos postlingüísticos implantados con los modelos Clarion CII o 90K CI. Resultados: Los niveles de umbral en campo libre fueron más bajos con los niveles T colocados 10% más alto que los niveles M y con los dos IDR más anchos. Los datos del grupo revelaron puntuaciones significativamente mayores con palabras CNC presentadas en un nivel suave con un IDR de 80 dB y 65 dB comparados con 50 dB. No obstante que no se encontraron diferencias significativas en los grupos entre los tres IDR para oraciones en ruido, si se presentaron diferencias significativas individuales. Conclusiones: La colocación de los niveles T más altos en 10% que la recomendación del fabricante, sobre los niveles M y el proporcionar opciones de IDR, en general pueden mejorar la percepción del lenguaje; no obstante, niveles mayores de T y IDR más anchas, pueden no ser apropiados para algunos usuarios. Con base en los resultados de este estudio, se proporcionan recomendaciones clínicas para la programación.     

低年龄段语前聋儿童人工耳蜗植入后汉语声调识别变化的分析

目的:探讨低年龄段经人工耳蜗植入的语前聋儿童经过开机一段时间后声调识别的变化特点。方法:选择29例已经接受人工耳蜗植入的低年龄语前聋儿童,按植入时年龄分为2组,即A组:3.0~4.5岁,B组:5.0~6.5岁,植入后平均开机时间为1.5~2.0年。采用聋康系统的《聋儿听觉言语康复评估词表》中主要反映声调识别的相应评估内容进行封闭项测试。结果:A组:同音单音节声调识别率为(63.00±16.75)%,双音节声调识别率为(75.60±11.18)%,单音节词识别率为(72.38±11.39)%。B组:同音单音节声调识别率为(49.46±13.91)%,双音节声调识别为(64.71±9.64)%,单音节词识别率为(55.71±8.59)%。所有正确识别率结果均大于机会水平。人工耳蜗植入后不同年龄组患儿有关声调识别的三项测试内容,低年龄组患儿均好于高年龄组,结果均差异有统计学意义。结论:对于语前聋行人工耳蜗植入的低年龄儿童,植入时年龄仍是影响植入后声调识别的重要因素之一,而在更能反映汉语声、韵、调特点的单音节词中差异更为明显,因此植入年龄是术后汉语学习的重要影响因素之一。     

Indication for the need of flexible and frequency specific mapping functions in cochlear implant speech processors

Categorical loudness scaling of electric and acoustic stimuli was performed in cochlear implant (CI) recipients equipped with Nucleus™ systems in order to achieve a normal loudness perception in the whole dynamic range of acoustic input. For each electrode, the lower and upper limits of electric stimulus were defined by the values corresponding to “very soft” and “too loud”. Within this dynamic range, the stimulus strength intervals associated to the verbal categories “soft”, “medium”, “loud” and “very loud” were determined. The same loudness categories were used for the scaling of acoustic stimuli. From both scaling experiments, the transduction of the CI system can be assessed and the parameters of the individual mapping function yielding a normal loudness growth can be derived. Deviations from optimum mapping can be corrected at least partially by manipulating the parameters of the mapping function. In many cases, however, one mapping function is not sufficient for all channels. The results argue in favour of the development of flexible and channel-specific mapping function parameters in future CI systems. Parts of this paper were presented at the 76th annual meeting of the Deutsche Gesellschaft für HNO-Heilkunde, Kopf- und Hals-Chirurgie in Erfurt on 8 May 2005.     

语速和耳语对人工耳蜗植入者言语识别效果的影响

目的研究不同语速和耳语式的言语是否会影响人工耳蜗植入者的言语识别效果。方法在本研究中,分别对一组人工耳蜗植入者和一组听力正常者进行以下4种不同说话方式的言语识别率测试：慢速言语、常速言语、快速言语和耳语。测试时,人工耳蜗植入者聆听由扬声器播放的未经处理的言语声,正常受试者聆听经4通道人工耳蜗处理的言语声,二者使用相同的原始测试材料。结果人工耳蜗植入组与正常对照组对4种不同说话方式的言语识别结果相似,当说话语速增加时言语识别率逐渐下降,耳语的识别率最差,对于人工耳蜗植入者来说快速言语的识别率显著低于慢速言语识别率。结论人工耳蜗植入者言语识别效果会随着所聆听言语的语速增加而降低,并且聆听耳语式的言语对人工耳蜗植入者来说是非常困难的。     

Influence of stimulation rate and loudness growth on modulation detection and intensity discrimination in cochlear implant users

In cochlear implants (CIs), increasing the stimulation rate typically increases the electric dynamic range (DR), mostly by reducing audibility thresholds. While CI users’ intensity resolution has been shown to be fairly constant across stimulation rates, high rates have been shown to weaken modulation sensitivity, especially at low listening levels. In this study, modulation detection thresholds (MDTs) were measured in five CI users for a range of stimulation rates (250–2000 pulses per second) and modulation frequencies (5–100 Hz) at 8 stimulation levels that spanned the DR (loudness-balanced across stimulation rates). Intensity difference limens (IDLs) were measured for the same stimulation rates and levels used for modulation detection. For all modulation frequencies, modulation sensitivity was generally poorer at low levels and at higher stimulation rates. CI users were sensitive to modulation frequency only at relatively high levels. Similarly, IDLs were poorer at low levels and at high stimulation rates. When compared directly in terms of relative amplitude, IDLs were generally better than MDTs at low levels. Differences in loudness growth between dynamic and steady stimuli might explain level-dependent differences between MDTs and IDLs. The slower loudness growth associated with high stimulation rates might explain the poorer MDTs and IDLs with high rates. In general, high stimulation rates provided no advantage in intensity resolution and a disadvantage in modulation sensitivity.     

多通道人工耳蜗在语前聋儿童及青少年中的应用

目的　通过对植入人工耳蜗的语前聋儿童和青少年的听力和语言能力的评估 ,探讨我国儿童在使用人工耳蜗后的听力和言语能力发展规律及影响因素。方法　 2 5例行人工耳蜗植入的语前聋儿童及青少年患者参与本组测试。选用《聋儿听觉言语康复评估方法》作为测试材料 ,分别进行声音、言语声和环境声的辨别 ,数词、单字词、双字词、3字词、韵母、声母、声调、封闭项列短句的识别 ,开放项列字词和开放项列短句识别 ,语言清晰度 ,模仿句长 ,听话识图和看图说话等方面测试。结果　受试者术后均能感知到声音 ,辨别不同类别的声音。封闭项列测试结果全部大于机会水平 ,正确识别率随人工耳蜗使用时间而不断增加 ,随植入时年龄的增长而呈下降趋势。术后约半年显现开放项列识别能力 ,使用人工耳蜗后对患儿的言语发育具有较大帮助。结论　尽早对语前聋患儿植入人工耳蜗及进行术后康复 ,以达改善听力 ,提高语言能力 ,促进身心全面发展的目的。     

Channel discrimination along all contacts of the cochlear implant electrode array and its relation to speech perception

Objective: To test the channel discrimination of cochlear implant (CI) users along all contacts of the electrode array and assess whether this is related to speech perception.

Design: CI recipients were tested with a custom-made channel discrimination test. They were asked to distinguish a target stimulus from two reference stimuli in a three-alternative forced choice (3AFC) task. The target stimulus was evoked using current steering, with current steering coefficients (α) of 1, 0.5 and 0.25. The test provided a discrimination score (Dα) for each electrode contact along the array.

Study sample: Thirty adults implanted with a CI from Advanced Bionics.

Results: Large variations in Dα scores were observed, both across the electrode array and between subjects. Statistical analysis revealed a significant channel-to-channel variability in Dα score (p?p?Conclusions: The large variations in Dα score emphasise the importance of testing pitch discrimination across the complete electrode array. The relationship between Dα score and speech perception indicates that pitch discrimination might be a contributing factor to the performance of individual implant users.     

Electroacoustic verification of frequency modulation systems in cochlear implant users

Introduction

The frequency modulation system is a device that helps to improve speech perception in noise and is considered the most beneficial approach to improve speech recognition in noise in cochlear implant users. According to guidelines, there is a need to perform a check before fitting the frequency modulation system. Although there are recommendations regarding the behavioral tests that should be performed at the fitting of the frequency modulation system to cochlear implant users, there are no published recommendations regarding the electroacoustic test that should be performed.

人工耳蜗植入患者术后言语康复效果的问卷评估

目的评价两种问卷式分级标准对人工耳蜗植入效果的直观评估效能。方法应用问卷式听觉行为分级标准和言语识别率分级标准分别评估人工耳蜗植入患者术后的言语感知能力和言语产生能力，并对患者的病程、术前助听器使用情况、植入时间、康复模式4个因素与康复效果之间的相关性进行统计学分析。结果人工耳蜗植入效果与患者的病程、植入时间的长短以及康复模式有关，而与术前助听器使用情况无关。结论听觉性行为分级标准及言语识别率分级标准能较客观地反映人工耳蜗植入患者术后听觉言语能力的真实水平。     

Preoperative functional assessment of auditory cortex in adult cochlear implant users

OBJECTIVES: To explore functional neuroanatomical responses to auditory stimulation before and after implantation. STUDY DESIGN: A prospective study of three cochlear implant candidates (pure-tone averages of 90 dB HL or greater bilaterally and hearing in noise test [HINT] performances of <40%) in which regional cerebral blood flow (rCBF) was assessed using single photon emission computed tomography (SPECT). METHODS: Candidates watched a 15-minute videotaped story under four conditions: audio presented monaurally in the right and left ears (aided), audio presented binaurally (aided), and visual-only presentation of the story. Five minutes into each story, 20 to 25 mCi of technetium 99m (99mTc) hexamethyl-propyleneamine-oxime (HMPAO) (Ceratec; Nycomed Amersham, Princeton, NJ, U.SA) was injected over a 30-second period to ensure that subjects were unaware of tracer administration. Subjects were scanned for 20 minutes using a PRISM 3000 gamma camera (Picker International, Cleveland, OH, U.S.A.). Data were normalized and co-registered, and subtraction images were compiled. Subtraction images contrasted activation patterns generated under the visual-only control condition to the auditory activation states acquired monaurally and binaurally. RESULTS: Right and left ear monaural stimulation in normal hearing subjects resulted in significant bilateral activation of Brodmann areas 41, 42, 21, 22, and 38. Although substantial intersubject response variability was noted, subjects generally failed to bilaterally activate these areas under monaural hearing aid presentations; however, bilateral activation of areas 41 and 22 was noted under binaural presentations. CONCLUSIONS: Despite relatively similar hearing losses in each ear, significant differences in preoperative auditory cortex activation were observed between ears. These data suggest that functional brain imaging provides a useful tool for exploring the responsiveness of the auditory cortex in cochlear implant candidates.     

普通话单音节测听表在人工耳蜗植入者中的初步应用

目的采用新编普通话单音节测听表,评估人工耳蜗植入者的言语识别能力。方法选取8名语前聋儿童（甲组）及13名语后聋（乙组）人工耳蜗植入者作为研究对象,男12名,女9名。甲组植入年龄为1．6～11．9岁（中位数2．7岁）,使用年限〉3．4年。乙组植入年龄为3．2～30．9岁（中位数12．0岁）,使用年限〉0．7年以上。在声场中测试人工耳蜗日常使用状态下的啭音听阈,并55dB SPL言语强度下的单音节识别率。部分受试者还接受了65、80dB SPL言语强度下单音节识别率的测试。结果甲乙2组受试者的0．5、1、2、4kHz四频率平均（4 Frequency Average,4FA）声场啭音听阈分别为32．5±3．4dB HL、35．9±4．9dB HL,t检验显示P=0．1046。甲乙2组受试者55dB SPL下的单音节识别率分别为56．8±9．0％、31．41±7．1％,t检验显示P=0．001。结论新编普通话单音节测听表,可有效地用来评价人工耳蜗植入者的言语识别能力。使用年限较短的语后聋患者的单音节识别率尚不及使用年限较长的语前聋儿童。人工耳蜗植入者的单音节识别率一言语声强（Performance—Intensity,P—I）函数曲线较正常成人平均右移30dB以上,提示人工耳蜗使用者的言语听力补偿水平较正常人仍有差距。     

Speech production intelligibility of early implanted pediatric cochlear implant users

Objectives

To investigate the influence of age, and age-at-implantation, on speech production intelligibility in prelingually deaf pediatric cochlear implant recipients.

Methods

Forty prelingually, profoundly deaf children who received cochlear implants between 8 and 40 months of age. Their age at testing ranged between 2.5 and 18 years. Children were recorded repeating the 10 sentences in the Beginner's Intelligibility Test. These recordings were played back to normal-hearing listeners who were unfamiliar with deaf speech and who were instructed to write down what they heard. They also rated each subject for the intelligibility of their speech production on a 5-point rating-scale. The main outcome measures were the percentage of target words correctly transcribed, and the intelligibility ratings, in both cases averaged across 3 normal-hearing listeners.

Results

The data showed a strong effect of age at testing, with older children being more intelligible. This effect was particularly pronounced for children implanted in the first 24 months of life, all of whom had speech production intelligibility scores of 80% or higher when they were tested at age 5.5 years or older. This was true for only 5 out of 9 children implanted at age 25-36 months.

Conclusions

Profoundly deaf children who receive cochlear implants in the first 2 years of life produce highly intelligible speech before the age of 6. This is also true for most, but not all children implanted in their third year.     

Identification and revision of a displaced cochlear implant electrode in the internal auditory canal

Abstract

Objective

The aim of the report is to underline the importance of a radiological technique which allows three-dimensional (3D) imaging of the cochlear implant electrode position postoperatively in cases of cochlear malformation, and to show a technique to prevent a repeat of cochlear implant electrode insertion in the internal auditory canal (IAC).

Clinical presentation

This report describes the management of a case of insertion of a cochlear implant electrode into the IAC in a 1.5-year-old patient with an incomplete partition (IP) III cochlear malformation.

Intervention and technique

The commonly used single plain postoperative X-ray is not sufficient to be certain of detecting the incorrect insertion of a cochlear implant electrode in the case of a malformed cochlea. In this case, 3D radiology allowed the incorrect insertion to be detected. The original cochlear implant electrode was temporarily left in place under the assumption that it would block the entrance to the IAC and prevent IAC insertion of the replacement electrode.

Conclusion

Postoperative 3D radiological observation after cochlear implant surgery should be done in cases of malformation. Leaving the original electrode in place can help to prevent a repeat electrode malinsertion.