Scalp thickness in the temporal region: its relevance to the development of cochlear implants

The thickness of the scalp in the temporal region was measured at two representative points: point 1, over the most laterally prominent part of the mastoid process: and point 2, at the horizontal level of the upper border of the orbit, vertically in line with point 1. Measurements were made directly at autopsy in four patients, then in 50 live patients by magnetic resonance imaging (MRI). The relevance of the methodology and of these measurements to cochlear implant development is discussed. As the term 'scalp' usually includes the periosteum of the skull, the authors have used the term 'scalp' to include the range from the surface of the scalp to the bone shadow as seen on MRI, and the term 'skin' where, at autopsy, the skin is lifted leaving the periosteum intact.     

Appreciation of music in adult patients with cochlear implants: a patient questionnaire

Abstract

Many cochlear implant candidates express hopes of enjoying music following implantation. Our aim was to assess the appreciation of music after cochlear implantation in adult patients. Thirty-five out of 45 cochlear implantees (78%) from the North East Programme responded to a questionnaire. Only 16 out of 35 patients (46%) listened to music after implantation. Enjoyment of music on a self-assessment scale was graded a mean of 8.7/10 before deafness but only 2.6/10 after implantation. Listening to music after implantation was more likely in younger patients, those with higher speech perception scores and those with a shorter length of deafness, but was not found to be related to gender, type of implant, processing strategy, time since implant or music enjoyment before becoming deaf. Appreciation of music after cochlear implantation is disappointingly low. Future developments in implant technology should strive to improve satisfaction with music listening.     

多导人工耳蜗植入术后耳蜗X线显像

目的 探索适合于评价多导人工耳蜗植入手术效果的术后影像学检查技术。方法 多导人工耳蜗植入术69例69耳,其中Nucleus直电极53耳,Nucleus弯电极11耳,Nucleus22导5耳。手术采用耳后面神经隐窝入路。建立放射线耳蜗显像技术,并且所有多导电子耳蜗植入病例术后7-10天均行耳蜗位头颅X-线检查。结果 在69例69耳手术中均成功地植入多导人工耳蜗电极。术后1.0-1.5月进行开机调试,听阈和言语分辨率均达到比较满意的水平。耳蜗位头颅X-平片显示上半规管和前庭易于辨认,可以作为影像学解剖的重要标志。耳蜗X线显像可以直接而且清晰地显示一个完整的人工耳蜗植入术后的电极在耳蜗内的图像,并且每一个电极阵列都可以很清楚地被识别。影像学检查可以作为植入手术结果的客观资料,而且如果电极扭曲或术后移位很容易发现。对于内耳畸形人工耳蜗植入术后,耳蜗位X-线检查则更现必要,是判断手术结果的重要依据。结论感音神经性耳聋患者植入多导人工耳蜗效果良好。头颅X-线耳蜗显像可以应用于对多导人工耳蜗植入术后结果的评价,而且简单、低放射量、快速和经济,值得广泛推广。     

Rate-of-processing ability in children using cochlear implants and its relevance to speech perception

Abstract

The aim was to assess the ability of young children using cochlear implants to process a change in place of stimulation under conditions of shortened stimulus duration and shortened interstimulus interval. The study investigated whether or not this ability accounted for a significant amount of the variance in the speech performance of the children additional to the variance accounted for by electrode discrimination ability (measured in a previous study). An adaptation of the play audiometry procedure was used to assess ‘rate-of-processing’ ability in 17 children aged between 4 and 10 years. Initially the child was required to respond with a gamelike motor response when a repeating stimulation on a reference electrode ‘changed’ to a different electrode in relatively ‘slow’ conditions. The child was then required to respond to the ‘change’, when the duration of the stimuli and the time interval between the stimuli were decreased. All but one of the children using cochlear implants scored significantly above chance for all conditions of stimulus duration and interstimulus interval assessed. That is, they were able to discriminate place pitch changes when these changes occurred more rapidly in time. A stepwise regression was computed to determine the relative contributions of a number of variables, including rate-of-processing ability, in accounting for variance in the children's speech perception performance (measured in a previous study). Rate-of-processing ability did not account for any variance additional to that accounted for by electrode discrimination ability, which was found to be the most significant predictor of speech perception performance for this group of children in the previous study.     

Tone perception in Mandarin-speaking children with cochlear implants

Abstract

Objective: To evaluate the effects of implant age and duration of implantation on development of Mandarin tone perception in paediatric cochlear implant recipients. Design: Retrospective cross-sectional evaluation of tone perception, as assessed with the Mandarin Early Speech Perception test at 3, 6, 12, 24, 36 and 48 months after activation. Study sample: A total of 143 subjects, 60 girls and 83 boys unilaterally implanted at 1–4 years of age comprised the sample. All the subjects were implanted with devices from one of three manufacturers. Results: Regardless of implant age, approximately 80% of the subjects obtained overall tone discrimination scores significantly above chance by 4 years after implantation, and average discrimination accuracy increased from approximately 68% to 79%. Acoustically distinct tones 1 and 4 were discriminated and recognised more accurately, while less distinct tones 2 and 3 were discriminated and recognised less accurately. Large individual differences in performance were evident. Conclusions: Most Mandarin-speaking paediatric CI recipients discriminate tones above chance at 5 years of age with accuracy comparable to that of children with normal hearing at 2 years of age. Modest benefits of early implantation are evident.     

Access to cochlear implants: Time to reflect

Cochlear implant (CI) intervention is expensive and accessed mainly by developed countries. The introduction of Universal Newborn Hearing Screening and funding via a public health service give children better access to CIs. However for adults large disparities exist between utilization and estimated prevalence. In the UK CI selection criteria are restrictive compared with many other countries. Improved audiological awareness and screening programmes for adults would improve access to hearing technologies that would improve health and quality of life. Hearing loss itself has significant medical and financial burdens on society and by investing in early intervention and using best technology this would mitigate some of the rising associated medical costs.     

Speech-ABRs in cochlear implant recipients: feasibility study

Abstract

Objective: The aim of this study was to assess the feasibility of recording speech-ABRs from cochlear implant (CI) recipients, and to remove the artefact using a clinically applicable single-channel approach.

Design: Speech-ABRs were recorded to a 40?ms [da] presented via loudspeaker using a two-channel electrode montage. Additionally, artefacts were recorded using an artificial-head incorporating a MED-EL CI with stimulation parameters as similar as possible to those of three MED-EL participants. A single-channel artefact removal technique was applied to all responses.

Study sample: A total of 12 adult CI recipients (6 Cochlear Nucleus and 6 MED-EL CIs).

Results: Responses differed according to the CI type, artefact removal resulted in responses containing speech-ARB characteristics in two MED-EL CI participants; however, it was not possible to verify whether these were true responses or were modulated by artefacts, and artefact removal was successful from the artificial-head recordings.

Conclusions: This is the first study that attempted to record speech-ABRs from CI recipients. Results suggest that there is a potential for application of a single-channel approach to artefact removal. However, a more robust and adaptive approach to artefact removal that includes a method to verify true responses is needed.     

Comparison of primary musicality development between children with cochlear implants and children with normal hearing

Abstract

Background: It is beneficial for CI patients listen to music. However it is necessary to take steps to improve the musicality of CI patients.

Objectives: The aims of the study were to evaluate the primary musicality of children with cochlear implants versus those with normal hearing.

Material and methods: Children participating in this study were divided into two groups: the cochlear implant group (CI group) and the normal hearing group (NH group). The ‘Musical Ears Evaluation Form for Professionals’ was used to evaluate the subjects’ primary musicality.

Results: The scores for overall and the three subcategories of primary musicality in children with cochlear implants and in those with normal hearing also improved significantly over time (p?<?.05). The score for overall primary musicality was not significantly different between CI and NH groups in the same hearing age (p?>?.05). There were significant differences between the two groups in the same chronological age (p?<?.05).

Conclusions and significance: The primary musicality in children with cochlear implants was not significantly different from normal hearing ones at the same hearing age. The primary musicality in children with cochlear implants was significantly lower than that of children with normal hearing at the same chronological age.     

Outcomes and achievement of students who grew up with access to cochlear implants

OBJECTIVES/HYPOTHESIS: To provide long-term speech perception and production, educational, vocational, and achievement outcome data for pediatric cochlear implant recipients. STUDY DESIGN: This is a retrospective study using consecutive referrals of prelingually, profoundly deaf children at the University of Iowa Hospitals and Clinics. METHODS: Twenty-seven prelingually deaf young adults who received a cochlear implant between the ages of 2 and 12 years participated. Outcome measures included device-use information, perceptual information, reading results for all participants and educational achievement results for 17 of 27 participants, educational placement information/vocational information for all students, as well as a comparison of the child's educational/vocational outcome with that of the parent's educational/vocational outcome. RESULTS: Speech perception and production scores were highly correlated. Achievement test results indicated that scores were within 1 SD from normative data based on hearing individuals. Over 50% of the college-age eligible students enrolled in college. This initial group of implant users had a nonuse rate of 11% in the first 3 years. Eighty-nine percent of the users maintained full-time use for 7 years, and 71% of this group have maintained full-time use to date. CONCLUSIONS: This cohort of cochlear implant users compared favorably with their hearing peers on academic achievement measures. Although there was a wide distribution of educational and vocational outcomes, the children tended to follow the educational/vocational patterns of their parents. As age of implantation decreases, it will be important to compare achievement outcomes of this first generation with those of subsequent generations of cochlear implant users.     

中国人工耳蜗植入儿童前语言交流能力发育研究

目的:探讨中国人工耳蜗植入儿童前语言交流能力的发展规律,为早期预测康复效果及制定合理的康复训练计划提供依据.方法:30例接受人工耳蜗植入手术的语前聋儿童参与本次研究,术前均为极重度聋.所有患儿使用人工耳蜗的时间均在12个月以内,平均5.8个月.使用录像分析法对患儿的轮流交流、主动交流、视觉交流及听觉注意等4项前语言交流能力进行分析和评估.结果:患儿的轮流交流能力呈快速增长趋势,其中有声回应能力也以相同的方式增长,而以肢体动作进行的回应则呈缓慢降低趋势.患儿主动交流和适时的视觉交流能力得分较低,呈缓慢增长,听觉注意能力呈逐步增长趋势.结论:随着人工耳蜗使用时间的增加,患儿初步建立起了"听/说"的交流模式,并越来越倾向于以发声的方式进行交流.录像分析法可用于评估中国人工耳蜗植入患儿前语言期交流能力.     

Speech perception in Mandarin-speaking children with cochlear implants: A systematic review

Abstract

Objective: This paper reviewed the literature on the trajectories and the factors significantly affecting post-implantation speech perception development in Mandarin-speaking children with cochlear implants (CIs). Design: A systematic literature search of textbooks and peer-reviewed published journal articles in online bibliographic databases was conducted. Study sample: PubMed, Scopus and Wiley online library were searched for eligible studies based on predefined inclusion and exclusion criteria. Results: A total of 14 journal articles were selected for this review. A number of consistent results were found. That is, children with CIs, as a group, exhibited steep improvement in early speech perception, from exhibiting few prelingual auditory behaviours before implantation to identifying sentences in noise after one year of CI use. After one to three years of CI use, children are expected to identify tones above chance and recognition of words in noise. In addition, early age at implantation, longer duration of CI use and higher maternal education level contributed to greater improvements in speech perception. Conclusions: Findings from this review will contribute to the establishment of appropriate short-term developmental goals for Mandarin-speaking children with CIs in mainland China and clinicians could use them to determine whether children have made appropriate progress with CIs.     

Nucleus 24 Contour人工耳蜗植入术初步体会

目的 报道16例Nucleus24Contour人工耳蜗的手术方法和初步效果。方法 介绍Nucleus24Contour人工耳蜗手术方法、注意事项和结果,与Nucleus24M人工耳蜗植入后的编程调试结果(T-Level,C-Level)进行比较。结果 16例病人术后4～5次编程调试后,声场测听达到20～35dB(HL),平均24.4±5.8dB,C-level。T-Level和C-Level均比Nucleuse24M要小,动态范围比Nucleus24M大。结论 初步结果显示,Nucleus24Contour人工耳蜗性能比Nucleus24M型人工耳蜗有某些提高,但手术时应注意操作特点。     

Effects of limiting the number of active electrodes on mandarin tone perception in young children using cochlear implants

Objective—To evaluate the short-term effects of varying the number and location of programmed electrodes on Mandarin tone perception in young children using Nucleus CI 24 implants.

Material and Methods—Six children using CI 24 implants participated in the study. The Mandarin tone recognition of each subject was assessed using a self-designed word list containing 80 words under 5 different map conditions. The map conditions were: (i) the subject's current map with all functional electrodes; (ii) removing (i.e. not programming) the even-numbered active electrodes; (iii) removing the five most apical electrodes; (iv) removing the six most basal electrodes; and (v) removing all electrodes except the six most apical.

Results—Reducing the number of active electrodes caused a small but significant decrease in performance of Mandarin tone perception. However, a relatively high tone perception score (58.1%) could be maintained even when subjects used only six apical electrodes. The location of the electrodes, i.e. apical or basal, did not appear to be important in tone perception. For each individual tone, the scores for tones 1 and 4 were significantly higher than those for tones 2 and 3 for all map conditions. Comparing tone perception with word recognition, reducing the number of active electrodes had a much more negative effect on word recognition.

Conclusions—A small but significant decrease in Mandarin tone perception was observed when the number of active electrodes was reduced in children using CI 24 implants. The location of the electrode is not important in tone recognition. Moreover, tone recognition is far more resistant than word recognition to the negative effects of reducing the number of active programmable electrodes, possibly because it relies mostly on temporal envelopes while word recognition requires more spectral details.     

Sound localization in patients with unilateral cochlear implants

Objectives To evaluate sound localization ability in totally deaf patients with unilateral cochlear implants and to estimate the ability to improve this function by training.

Design A controlled case series.

Materials and methods Nine patients with monaural cochlear implants were asked to identify the source of 50 randomly distributed sound stimuli coming from five different directions anteriorly or laterally. After some training, patients were retested. There were two control groups. One comprised nine adults with normal hearing, and the other comprised nine adults with normal hearing but one ear plugged.

Results The mean initial score of the study group (maximal score 100) was 41.5 (range 23-63). Patients who had used cochlear implants longer had better sound localization ability (Spearman's correlation coefficient = 0.92). On retesting, after an average of 6.3 training sessions, their mean score improved to 66 (range 32-95), (p=0.008). The improvement was more pronounced in postlinguals than in prelinguals (p=0.016).

Conclusions Spontaneous development of sound localization ability in totally deaf patients with unilateral cochlear implants is proprtional to the time interbal between implantation and initial testing. Improvement appears to be influenced by training, and to be greater in postlingual than prelingual implantees.     

Threshold and loudness functions for pulsatile stimulation of cochlear implants

Thresholds and loudness estimates were measured for biphasic pulsatile electrical stimulation of the auditory nerve. Measures were collected as a function of the parameters: pulse duration, and pulse rate. The results indicate that the sensations of threshold and loudness are determined by a complex function of the stimulating current waveform. For stimuli with the same charge, maximum loudness is seen at the shortest pulse durations, and a secondary maximum is seen at pulse durations of 2-3 ms/phase. It is possible that the secondary peak in the loudness function and the slow growth of loudness just above threshold for long pulses are indications of dendrite survival near the electrode. If this interpretation is valid, these measures could lead to perceptual tests of peripheral nerve viability. In addition, a speech processor device could use these measures to equalize the loudness of stimuli with different pulse durations and pulse rates.     

Remote programming of cochlear implants in users of all ages

Background: Remote programming for adult cochlear implant (CI) users is feasible, safe, and effective. Limited evidence, however, exists on if remote CI programming can also be productively done with paediatric CI users.

Aims/objectives: To assess the safety and feasibility of remote CI programming in CI users for all ages.

Materials and methods: Forty-six (25 children, 21 adults) experienced CI users were fit locally and remotely. The results of these two fitting sessions were compared in terms of safety, Impedance Field Telemetry (IFT), Maximum Comfortable Levels (MCL), Threshold Levels (THR), audiometry, fitting duration, and speech understanding.

Results: The subjects’ safety was not compromised during any of the fitting procedures. No significant difference was found for IFT, MCL, THR, audiometry, or speech understanding for either remote or local fitting. Remote fittings took slightly longer than local fittings when only the fitting time itself was measured.

Conclusions and significance: Remote follow-up fitting is as safe, feasible, and effective as local fitting for CI users of all ages. A more extensive adoption of remote fitting may allow many CI users greater access to clinics and therefore increased benefit from CI use.