Article

Production of Tone 2 in disyllabic words in Mandarin Chinese speaking children aged 3-5 with a cochlear implant and a contralateral hearing aid

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Abstract

To investigate Mandarin Tone 2 production of disyllabic words of prelingually deafened children with a cochlear implant (CI) and a contralateral hearing aid (HA) and to evaluate the relationship between their demographic variables and tone-production ability. Thirty prelingually Mandarin-speaking preschoolers with CI+HA and 30 age-matched normal-hearing (NH) children participated in the study. Fourteen disyllabic words were recorded from each child. A total of 840 tokens (14 × 60) were then used in tone-perception tests in which four speech therapists participated. The production of T2-related disyllabic words of the bimodal group was significantly worse than that of the NH group, as reflected in the overall accuracy (88.57% ± 16.31% vs 99.29% ± 21.79%, p < 0.05), the accuracy of T1+T2 (93.33% vs 100%), the accuracy of T2+T1 (66.67 ± 37.91% vs 98.33 ± 9.13%), and the accuracy of T2+T4 (78.33 ± 33.95% vs 100%). In addition, the bimodal group showed significantly inferior production accuracy of T2+T1 than T2+T2 and T3+T2, p < 0.05. Both bimodal age and implantation age were significantly negatively correlated with the overall production accuracy, p < 0.05. For the error patterns, bimodal participants experienced more errors when T2 was in the first position of the tone combination, and T2 was most likely to be mispronounced as T1 and T3. Bimodal patients aged 3-5 have T2-related disyllabic lexical tone production defects, and their performances are related to tone combination, implantation age, and bimodal age.

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Previous studies have demonstrated the importance of both kinesthetic and auditory feedback for control of voice fundamental frequency (F 0). In the present study, a possible interaction between auditory feedback and kinesthetic feedback for control of voice F 0 was tested by administering local anesthetic to the vocal folds in the presence of perturbations in voice pitch feedback. Responses to pitch-shifted voice feedback were larger when the vocal fold mucosa was anesthetized than during normal kinesthesia. A mathematical model incorporating a linear combination of kinesthesia and pitch feedback simulated the main aspects of our experimental results. This model indicates that a feasible explanation for the increase in response magnitude with vocal fold anesthesia is that the vocal motor system uses both pitch and kinesthesia to stabilize voice F 0 shortly after a perturbation of voice pitch feedback has been perceived.
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The aim of the study was (1) to develop methods for evaluating tone production of children with cochlear implants (CIs) who speak Mandarin Chinese and (2) to evaluate the efficacy of using these methods to assess tone production. The subjects included two groups of native-Mandarin-Chinese-speaking children: 14 prelingually deafened children who had received CIs and 61 normal-hearing (NH) children as controls. The acoustic analysis focused on quantification of the degree of differentiation among lexical tones based on tonal ellipses and the overall similarity of tone contours produced by the children with CIs to normative contours derived from the 61 NH children. An artificial neural network was used to recognize tones produced by the children with CIs after trained with tone tokens produced by the NH children. Finally, perceptual judgments on the tone production of both groups were obtained from eight native-Mandarin-speaking NH adults to evaluate the efficacy of the methods. The results showed that all measures using the acoustic, neural-network, and perceptual analyses were highly correlated with each other and could be used to effectively evaluate tone production of children with CIs.
Article
In tonal languages, speech variability arises in both lexical tone (i.e., suprasegmentally) and vowel quality (segmentally). Listeners can use surrounding speech context to overcome variability in both speech cues, a process known as extrinsic normalization. Although vowels are the main carriers of tones, it is still unknown whether the combined percept (lexical tone and vowel quality) is normalized integrally or in partly separate processes. Here we used electroencephalography (EEG) to investigate the time course of lexical tone normalization and vowel normalization to answer this question. Cantonese adults listened to synthesized three-syllable stimuli in which the identity of a target syllable — ambiguous between high vs. mid-tone (Tone condition) or between/o/vs./u/(Vowel condition) — was dependent on either the tone range (Tone condition) or the formant range (Vowel condition) of the first two syllables. It was observed that the ambiguous tone was more often interpreted as a high-level tone when the context had a relatively low pitch than when it had a high pitch (Tone condition). Similarly, the ambiguous vowel was more often interpreted as/o/when the context had a relatively low formant range than when it had a relatively high formant range (Vowel condition). These findings show the typical pattern of extrinsic tone and vowel normalization. Importantly, the EEG results of participants showing the contrastive normalization effect demonstrated that the effects of vowel normalization could already be observed within the N2 time window (190-350 ms), while the first reliable effect of lexical tone normalization on cortical processing was observable only from the P3 time window (220-500 ms) onwards. The ERP patterns demonstrate that the contrastive perceptual normalization of lexical tones and that of vowels occur at least in partially separate time windows. This suggests that the extrinsic normalization can operate at the level of phonemes and tonemes separately instead of operating on the whole syllable at once.
Article
Purpose To better define the contributions of somatosensory and auditory feedback in vocal motor control, a laryngeal perturbation experiment was conducted with and without masking of auditory feedback. Method Eighteen native speakers of English produced a sustained vowel while their larynx was physically and externally displaced on a subset of trials. For the condition with auditory masking, speech-shaped noise was played via earphones at 90 dB SPL. Responses to the laryngeal perturbation were compared to responses by the same participants to an auditory perturbation experiment that involved a 100-cent downward shift in fundamental frequency ( f o ). Responses were also examined in relation to a measure of auditory acuity. Results Compensatory responses to the laryngeal perturbation were observed with and without auditory masking. The level of compensation was greatest in the laryngeal perturbation condition without auditory masking, followed by the condition with auditory masking; the level of compensation was smallest in the auditory perturbation experiment. No relationship was found between the degree of compensation to auditory versus laryngeal perturbations, and the variation in responses in both perturbation experiments was not related to auditory acuity. Conclusions The findings indicate that somatosensory and auditory feedback control mechanisms work together to compensate for laryngeal perturbations, resulting in the greatest degree of compensation when both sources of feedback are available. In contrast, these two control mechanisms work in competition in response to auditory perturbations, resulting in an overall smaller degree of compensation. Supplemental Material https://doi.org/10.23641/asha.12559628
Article
Objective: To assess the recognition of lexical tones in Mandarin-speaking bimodal cochlear implant (CI) subjects. Design: Lexical tone recognition in quiet and noise (SNR= +5 dB) was measured with electric stimulation (CI alone) or bimodal stimulation (CI + hearing aid (HA)). The recognition and confusion rates of the four tones (T1, T2, T3 and T4) were analysed. Spearman correlation analysis was performed to examine the relationship between hearing levels in the contralateral ear and bimodal benefits. Study sample: Twenty native Mandarin-speaking bimodal CI users, with ages ranging from 16–49 years. Results: Relative to the CI alone, mean tone recognition with the CI + HA improved significantly from 84.1–92.1% correct in quiet (+8 points) and from 57.9–73.1% correct in noise (+15.2 points). Tone confusions between T2 and T3 were the most prominent in all test conditions, and T4 tended to be labelled as T3 in noise. There was no significant correlation between the bimodal benefits for tone recognition and the unaided or HA-aided pure-tone thresholds at 0.25 kHz. Conclusion: Listeners with CI + HA exhibited significantly better tone recognition than with CI alone. The bimodal advantage for tone recognition was greater in noise than in quiet, perhaps due to a ceiling effect in quiet.
Article
Purpose Previous studies showed early production precedes late perception in Cantonese tone acquisition, contrary to the general principle that perception precedes production in child language. How tone production and perception are linked in 1st language acquisition remains largely unknown. Our study revisited the acquisition of tone in Cantonese-speaking children, exploring the possible link between production and perception in 1st language acquisition. Method One hundred eleven Cantonese-speaking children aged between 2;0 and 6;0 (years;months) and 10 adolescent reference speakers participated in tone production and perception experiments. Production materials with 30 monosyllabic words were transcribed in filtered and unfiltered conditions by 2 native judges. Perception accuracy was based on a 2-alternative forced-choice task with pictures covering all possible tone pair contrasts. Results Children's accuracy of production and perception of all the 6 Cantonese tones was still not adultlike by age 6;0. Both production and perception accuracies matured with age. A weak positive link was found between the 2 accuracies. Mother's native language contributed to children's production accuracy. Conclusions Our findings show that production and perception abilities are associated in tone acquisition. Further study is needed to explore factors affecting production accuracy in children. Supplemental Material https://doi.org/10.23641/asha.7960826
Article
Hypothesis: Early identification and intervention, earlier cochlear implantation, and mother's level of education will directly and/or indirectly impact the language outcomes of children with cochlear implants (CIs). Background: Identifying factors that contribute to the wide range of language outcomes in children who use CIs will assist healthcare and rehabilitation professionals in optimizing service delivery for this population. Universal newborn hearing screening provides an opportunity to examine the relationship between meeting the early hearing detection and intervention (EHDI) 1-3-6 guidelines and child language outcomes. These guidelines recommend screening by 1 month, confirmation of hearing loss by 3 months, and intervention by 6 months of age. Methods: Participants were 125 children with CIs ranging from 13 to 39 months of age. Language ability was measured using the Child Development Inventory and MacArthur-Bates Communicative Development Inventories. Results: Meeting EHDI 1-3-6, higher levels of maternal education and earlier cochlear implant activation had a direct, positive impact on language outcomes. Meeting the EHDI 1-3-6 guidelines also had an indirect positive effect on language outcomes via increasing the probability that the children's CIs would be activated earlier. Maternal education did not significantly predict age of cochlear implant activation nor whether a child met EHDI 1-3-6. Conclusion: Ensuring families meet the EHDI 1-3-6 guidelines is an early step that can lead to higher language outcomes and also earlier cochlear implantation.
Article
Hearing loss is a widespread condition that is linked to declines in quality of life and mental health. Hearing aids remain the treatment of choice, but, unfortunately, even state-of-the-art devices provide only limited benefit for the perception of speech in noisy environments. While traditionally viewed primarily as a loss of sensitivity, hearing loss is also known to cause complex distortions of sound-evoked neural activity that cannot be corrected by amplification alone. This Opinion article describes the effects of hearing loss on neural activity to illustrate the reasons why current hearing aids are insufficient and to motivate the use of new technologies to explore directions for improving the next generation of devices.
Article
Purpose: Research into the phonological development of Chinese children is in its infancy compared with the relatively extensive data available on the English-speaking population. This article provided a comprehensive review of empirical studies on the acquisition of Mandarin phonology. Method: Studies over the past 45 years that describe phonological development in Mandarin-speaking children were located through electronic databases, citation searches, keyword searches through online search engines, and manual searches of libraries. The research design of the studies was reviewed, and findings of acceptable studies were summarized. Results: After reviewing the abstracts of 798 studies, a total of 12 that met the inclusion criteria were retained. These studies are discussed with reference to the demographic background of participants, geographic regions, aspects of speech sounds measured, data collection tools, transcription systems used, reliability, and the main findings. Conclusions: The general developmental patterns reported were consistent. The methodological design varied substantially. These discrepancies, however, provide insights for further systematic investigations into phonological development in Mandarin.
Article
Objective: This study explored tone production, tone perception and intelligibility of produced speech in Mandarin-speaking prelingually deaf children with at least 5 years of cochlear implant (CI) experience. Another focus was on the predictive value of tone perception and tone production as they relate to speech intelligibility. Design: Cross-sectional research. Study sample: Thirty-three prelingually deafened children aged over eight years with over five years of experience with CI underwent tests for tone perception, tone production, and the Speech Intelligibility Rating (SIR). A Pearson correlation and a stepwise regression analysis were used to estimate the correlations among tone perception, tone production, and SIR scores. Results: The mean scores for tone perception, tone production, and SIR were 76.88%, 90.08%, and 4.08, respectively. Moderately positive Pearson correlations were found between tone perception and production, tone production and SIR, and tone perception and SIR (p < 0.01, p < 0.01 and p < 0.01, respectively). In the stepwise regression analysis, tone production, as the major predictor, accounted for 29% of the variations in the SIR (p < 0.01). Conclusions: Mandarin-speaking cochlear-implanted children with sufficient duration of CI use produce intelligent speech. Speech intelligibility can be predicted by tone production performance.
Article
This study examines the discrimination of Mandarin vowels and tones by native English speakers with varying amounts of Mandarin experience, aiming to investigate the relative difficulty of these two types of sounds for English speakers at different learning stages, and the source of their difficulty. Seventeen advanced learners of Mandarin (Ex group), eighteen beginning learners (InEx group), and eighteen English speakers naïve to Mandarin (Naïve group) participated in an AXB discrimination task. The stimuli were two Mandarin vowel contrasts, /li-ly/ and /lu-ly/, and two tonal contrasts, T1-T4 and T2-T3. The predicted difficulty for each contrast was hypothesized based on the assimilation of these sounds to English reported in previous work. The results showed that the Naïve group was more accurate with vowel contrasts than with tones, suggesting that non-tonal language speakers without any Mandarin training are less sensitive to tonal distinction than to vowels. The two learner groups, on the other hand, were highly accurate with all contrasts except for the T2-T3 pair, and achieved significantly higher accuracy than the Naïve group on /li-ly/ and T1-T4. This lends support to the view that experience in Mandarin improves English speakers' sensitivity to tonal distinction, helping them discriminate some tones as accurately as vowels. However, all three groups achieved low accuracy in discriminating T2 and T3, suggesting that this contrast may be inherently difficult and resistant to improvement. This study shows that various factors in addition to the native language experience may affect the perception of non-native vowels and tones.
Article
Treatment with cochlear implants (CIs) in single-sided deaf individuals started less than a decade ago. CIs can successfully reduce incapacitating tinnitus on the deaf ear and allow, so some extent, the restoration of binaural hearing. Until now, systematic evaluations of subjective CI benefit in post-lingually single-sided deaf individuals and analyses of speech intelligibility outcome for the CI in isolation have been lacking. For the prospective part of this study, the Bern Benefit in Single-Sided Deafness Questionnaire (BBSS) was administered to 48 single-sided deaf CI users to evaluate the subjectively perceived CI benefit across different listening situations. In the retrospective part, speech intelligibility outcome with the CI up to 12 month post-activation was compared between 100 single-sided deaf CI users and 125 bilaterally implanted CI users (2nd implant). The positive median ratings in the BBSS differed significantly from zero for all items suggesting that most individuals with single-sided deafness rate their CI as beneficial across listening situations. The speech perception scores in quiet and noise improved significantly over time in both groups of CI users. Speech intelligibility with the CI in isolation was significantly better in bilaterally implanted CI users (2nd implant) compared to the scores obtained from single-sided deaf CI users. Our results indicate that CI users with single-sided deafness can reach open set speech understanding with their CI in isolation, encouraging the extension of the CI indication to individuals with residual and even normal hearing on the contralateral ear. Compared to the performance reached with bilateral CI users' second implant, speech reception threshold are lower, indicating an aural preference and dominance of the normal hearing ear. The results from the BBSS propose good satisfaction with the CI across several listening situations.
Article
Objective: Examine the influence of age at implant on speech perception, language and speech production outcomes in a large unselected paediatric cohort. Study Design: This study pools available assessment data (collected prospectively and entered into respective databases from 1990 to 2014) from three Australian centres. Patients: Children (N=403) with congenital bilateral severe to profound hearing loss who received cochlear implants under 6 years of age (excluding those with acquired onset of profound hearing loss after 12 months, those with progressive hearing loss and those with mild/moderate/severe additional cognitive delay/disability). Main Outcome Measure(s): Speech Perception; open-set words (scored for words and phonemes correct) and sentence understanding at school entry and late primary school time points. Language; PLS and PPVT standard score equivalents at school entry, CELF standard scores. Speech Production; DEAP percentage accuracy of vowels, consonants, phonemes-total and clusters and percentage word-intelligibility at school entry. Results: Regression analysis indicated a significant effect for age-at-implant for all outcome measures. Cognitive skills also accounted for significant variance in all outcome measures except open-set phoneme scores. ANOVA with Tukey pairwise comparisons examined group differences for children implanted younger than 12 months (Group 1), between 13 and 18 months (Group 2), between 19 and 24 months (Group 3), between 25 and 42 months (Group 4), and between 43 to 72 months (Group 5). Open-set speech perception scores for Groups 1, 2 and 3 were significantly higher than Groups 4 and 5. Language standard scores for Group 1 were significantly higher than Groups 2, 3, 4 and 5. Speech production outcomes for Group 1 were significantly higher than scores obtained for Groups 2, 3, and 4 combined. Cross tabulation and Chi-square tests supported the hypothesis that a greater percentage of Group 1 children (than Groups 2, 3, 4, or 5) demonstrated language performance within the normative range by school entry. Conclusions: Results support provision of cochlear implants younger than 12 months of age for children with severe to profound hearing loss to optimize speech perception and subsequent language acquisition and speech production accuracy.
Article
Objectives: For cochlear implant (CI) users with residual low-frequency acoustic hearing in the nonimplanted ear, bimodal hearing combining the use of a CI and a contralateral hearing aid (HA) may provide more salient talker voice cues than CI alone to handle the variability of talker identity across trials. This study tested the effects of talker variability, bimodal hearing, and their interaction on response accuracy and time of CI users' Mandarin tone, vowel, and syllable recognition (i.e., combined Mandarin tone and vowel recognition in this study). Design: Fifteen prelingually deafened native Mandarin-speaking CI users (at age 20 or lower) participated in this study. Four talkers each produced six Mandarin single-vowel syllables in four lexical tones. The stimuli were presented in quiet via a single loudspeaker. To study the effects of talker variability, Mandarin tone, vowel, and syllable recognition was tested in two presentation conditions: with stimuli blocked according to talker (blocked-talker condition) or mixed across talkers from trial to trial (mixed-talker condition). To explore the effects of bimodal hearing, two processor conditions were tested: CI alone or CI + HA. The cumulative response time was recorded as an indirect indicator of the cognitive load or listening effort in each condition. The correlations were computed between demographic/hearing factors (e.g., hearing thresholds in the nonimplanted ear) and bimodal performance/benefits (where bimodal benefits refer to the performance differences between CI alone and CI + HA). Results: Mandarin tone recognition with both CI alone and CI + HA was significantly poorer in the mixed-talker condition than in the blocked-talker condition, while vowel recognition was comparable in the two presentation conditions. Bimodal hearing significantly improved Mandarin tone recognition but not vowel recognition. Mandarin syllable recognition was significantly affected by both talker variability and bimodal hearing. The cumulative response time significantly reduced with CI + HA compared with CI alone, but remained invariant with respect to talker variability. There was no interaction between talker variability and bimodal hearing for any performance measure adopted in this study. Correlation analyses revealed that the bimodal performance and benefits in Mandarin tone, vowel, and syllable recognition could not be predicted by the hearing thresholds in the nonimplanted ear or by the demographic factors of the participants. Conclusions: Talker variability from trial to trial significantly degraded Mandarin tone and syllable recognition performance in both the CI alone and CI + HA conditions. While bimodal hearing did not reduce the talker variability effects on Mandarin tone and syllable recognition, generally better Mandarin tone and syllable recognition performance with shorter response time (an indicator of less listening effort) was observed when a contralateral HA was used in conjunction with the CI. On the other hand, vowel recognition was not significantly affected by either talker variability or bimodal hearing, because ceiling effects could not be counted out of the vowel recognition results.
Article
The present study recorded both behavioral data and event-related brain potentials to examine the effectiveness of a perception-only training and a perception-plus-production training procedure on the intentional and unintentional perception of lexical tone by native English listeners. In the behavioral task, both the perception-only and the perception-plus-production groups improved on the tone discrimination abilities after the training session. Moreover, the participants in both groups generalized the improvements gained through the trained stimuli to the untrained stimuli. In the ERP task, the Mismatch Negativity was smaller in the post-training task than in the pre-training task. However, the two training groups did not differ in tone processing at the intentional or unintentional level after training. These results suggest that the employment of the motor system does not specifically benefit the tone perceptual skills. Furthermore, the present study investigated whether some tone pairs are more easily confused than others by native English listeners, and whether the order of tone presentation influences non-native tone discrimination. In the behavioral task, Tone2-Tone1 (rising-level) and Tone2-Tone4 (rising-falling) were the most difficult tone pairs, while Tone1-Tone2 and Tone4-Tone2 were the easiest tone pairs, even though they involved the same tone contrasts respectively. In the ERP task, the native English listeners had good discrimination when Tone2 and Tone4 were embedded in strings of Tone1, while poor discrimination when Tone1 was inserted in the context of Tone2 or Tone4. These asymmetries in tone perception might be attributed to the interference of native intonation system and can be altered by training. Copyright © 2015. Published by Elsevier B.V.
Article
Despite significant research and important clinical correlates, direct neural evidence for a phonological loop linking speech perception, short-term memory and production remains elusive. To investigate these processes, we acquired whole-head magnetoencephalographic (MEG) recordings from human subjects performing a variable-length syllable sequence reproduction task. The MEG sensor data were source localized using a time-frequency optimized spatially adaptive filter, and we examined the time courses of cortical oscillatory power and the correlations of oscillatory power with behavior between onset of the audio stimulus and the overt speech response. We found dissociations between time courses of behaviorally relevant activations in a network of regions falling primarily within the dorsal speech stream. In particular, verbal working memory load modulated high gamma power in both Sylvian-parietal-temporal and Broca's areas. The time courses of the correlations between high gamma power and subject performance clearly alternated between these two regions throughout the task. Our results provide the first evidence of a reverberating input-output buffer system in the dorsal stream underlying speech sensorimotor integration, consistent with recent phonological loop, competitive queuing, and speech-motor control models. These findings also shed new light on potential sources of speech dysfunction in aphasia and neuropsychiatric disorders, identifying anatomically and behaviorally dissociable activation time windows critical for successful speech reproduction.
Article
(1) To determine the long-term outcomes of cochlear implantation in children implanted younger than 6 months and (2) to evaluate auditory-based performance in very young children compared with older children, all with profound sensorineural bilateral hearing loss. Prospective cohort study. Tertiary referral center. Twelve subjects aged 2 to 6 months, 9 aged 7 to 12 months, 11 aged 13 to 18 months, and 13 aged 19 to 24 months, all with profound bilateral hearing loss, were fitted with cochlear implants and followed longitudinally for 4 years. Subjects were developmentally normal with no additional disabilities (visual, motor, or cognitive). Auditory-based communication outcomes included tests for speech perception, receptive language development, receptive vocabulary, and speech production. Age at cochlear implantation was a significant factor in most outcome measures, contributing significantly to speech perception, speech production, and language outcomes. There were no major complications and no significantly higher rates of minor complications in the younger children. This article reports an uncontrolled observational study on a small group of infants fitted with cochlear implants following personal audiological criteria and, up to now, with limited literature support due to the innovative nature of the study. This study shows, for the first time, significantly improved auditory-based outcomes in children implanted younger than 6 months and without an increased rate of complications. The data from the present study must be considered as explorative, and a more extensive study is required.
Article
The depth of electrode insertion of a multichannel cochlear implant has been suggested as a clinical variable that may correlate with word recognition using the implant. The current study evaluates this relationship using the human temporal bone collection at the Massachusetts Eye and Ear Infirmary. Twenty-seven temporal bones of subjects with cochlear implants were studied. Temporal bones were removed at autopsy, fixed and prepared for histological study by standard techniques. Specimens were then serially sectioned, and reconstructed by two-dimensional methods. Three measures of length were made from each subject's reconstruction: (1) depth of insertion (DI) of the cochlear implant electrode array, from the round window to the array's apical tip; (2) inserted length (IL) from the cochleostomy to the apical tip of the array, and (3) cochlear duct length (CDL) from the round window to the helicotrema. The active electrode length (AEL) was defined as the distance between the most apical and most basal electrodes of the array. Stepwise regression was used to identify whether subsets of six metrics associated with insertion depth (DI, DI/AEL, DI/CDL, IL, IL/AEL and IL/CDL), duration of deafness, sound-processing strategy, potential for central impairment and age at implantation accounted for significant across-subject variance in the last recorded NU-6 word score measured during each subject's life. Age at implantation and potential for central impairment account for significant percentages of the across-subject variance in NU-6 word scores for the 27 subjects studied. None of the insertion metrics accounted for significant performance variance, even when the variance associated with the other variables was controlled. These results, together with those of previous studies, are consistent with a relatively weak association between electrode insertion depth and speech reception.
Article
In this study the outcomes from several indices (Category of Auditory Performance, CAP; Peabody Picture Vocabulary Test (Revised), PPVT-R; Test of Reception of Grammar, TROG; and Speech Intellegibility Rating, SIR) in three groups of children with different ages at implantation (from 4 to 36 months) with a follow-up time from 4 to 9 years demonstrate that very early cochlear implantation (<11 months) provides normalization of audio-phonologic parameters with no complications. The aim of the present study was to investigate the efficacy of cochlear implants (CIs) in infants who were implanted at < 11 months of age versus children operated at later age (i.e. 12-36 months) and to document whether children who receive a CI below 11 months of age are able to achieve age-appropriate expected spoken language skills, at a follow-up time from 4 to 9 years. From November 1998 to November 2007, 185 children received CIs and 34 received auditory brainstem implants in our department. The present study focuses on 13 children implanted at ages younger than 12 months (4-11 months; mean, 8.2; SD = 2.4) and fitted with CIs between November 1998 and March 2004. To avoid bias these children were selected from a larger longitudinal cohort of pediatric CI recipients fitted with CIs because they all were implanted with the same cochlear device (Nucleus CI 24 M) during the same period. Postoperatively auditory abilities were evaluated at the latest follow-up, from 4 to 9 years after surgery, with CAP, PPVT-R, TROG, and SIR. The results obtained in this group of 13 children were compared with those obtained in two groups of children implanted at later ages (12-23 and 24-36 months, respectively). No complication has been observed so far. The highest score of CAP function was achieved in all the three groups but at different intervals from CI activation as function of age at CI implantation. The rate of receptive language growth (PPVT-R) provides distinctive evidence that only the scores of the first group overlap the line of normal-hearing children, whereas the second and third group never reached the values of normal peers even after 9 years of CI use. TROG outcomes clearly indicate that only children from the first group (77%) are in the 76-100 percentile at 5 years follow-up. At 9 years follow-up, 100% of children in the first group, 38% in the second group, and 20% in the third group are in the 76-100 percentile. The SIR outcomes at the 5 years follow-up indicate that none of children was identified within the first two categories, only children from the third group (18%) were identified in category 3, all infants of the first group, 80% of group 2, and 63% of the third group were identified in category 5. At the 9 years follow-up, the number of children from the third group identified in category 3 was reduced to 10%, the second and third groups displayed a slightly higher percentage of children in category 5, but the difference from the values observed at the 5-year follow-up is not significant.
Article
Mandarin is a lexical tone language in which four tones are crucial for determining lexical meanings. Acquisition of such a tone system may be challenging to prelingually deaf children with cochlear implants because, as recent studies have shown, cochlear implant devices are ineffective in encoding voice pitch information required for tone recognition. This study aimed to investigate Mandarin tone production and perception skills of children with cochlear implants. Thirty prelingually deaf children with cochlear implants, ages 6;0 (yr;mo) to 12;6, participated. These children received their implants at an average age of 5;8, with a range from 2;3 to 10;3. The average length of their cochlear implant experience was 3;7, with a range from 1;7 to 6;5. Tasks of tone production and tone identification involved a pictorial protocol of 48 words containing the targeted tones in either monosyllabic or disyllabic forms. The average scores for tone production was 53.09% (SD = 15.42), and for tone identification was 72.88% (SD = 19.68; chance level = 50%). Significant differences were found in the percentages across the production or identification of tone types or tone pairs. The children with exceptional performance in tone production tended to also perform well in tone identification. The children's performance levels in tone identification and production were also discussed in relation to the factors of age at implantation and length of cochlear implant experience. The present results suggest that the majority of prelingually deaf children with cochlear implants did not master Mandarin tone production. However, a small group of participants demonstrated nearly perfect skills of Mandarin tone production in addition to tone perception. Thus, it is necessary to consider factors other than the device's limitations to explain these high levels of performance in the perception and production of Mandarin lexical tones.
Article
Unlabelled: A fundamental problem for those interested in human communication is to determine how ideas and the various units of language structure are communicated through speaking. The physiological concepts involved in the control of muscle contraction and movement are theoretically distant from the processing levels and units postulated to exist in language production models. A review of the literature on adult speakers suggests that they engage complex, parallel processes involving many units, including sentence, phrase, syllable, and phoneme levels. Infants must develop multilayered interactions among language and motor systems. This discussion describes recent studies of speech motor performance relative to varying linguistic goals during the childhood, teenage, and young adult years. Studies of the developing interactions between speech motor and language systems reveal both qualitative and quantitative differences between the developing and the mature systems. These studies provide an experimental basis for a more comprehensive theoretical account of how mappings between units of language and units of action are formed and how they function. Learning outcomes: Readers will be able to: (1) understand the theoretical differences between models of speech motor control and models of language processing, as well as the nature of the concepts used in the two different kinds of models, (2) explain the concept of coarticulation and state why this phenomenon has confounded attempts to determine the role of linguistic units, such as syllables and phonemes, in speech production, (3) describe the development of speech motor performance skills and specify quantitative and qualitative differences between speech motor performance in children and adults, and (4) describe experimental methods that allow scientists to study speech and limb motor control, as well as compare units of action used to study non-speech and speech movements.