Speech perception of Mandarin Chinese speaking young children after cochlear implant use: effect of age at implantation

Tone perception development in Mandarin-speaking children with cochlear implants

OBJECTIVE

The purpose of this study was to examine the longer-term effects of cochlear implant (CI) use on tone perception by evaluating improvement in Mandarin tone recognition in children with CIs 2 and 3 years post CI activation, and to explore the effects of implant age, chronological age and duration of CI use on the development of tone perception.

METHODS

Tone perception was assessed in 29 bilateral profound hearing impaired children (mean chronological age = 4.6 years, SD = 0.7 years) with unilateral CIs at 24 and 36 months after CI activation using the tone perception subtest in the Mandarin Early Speech Perception (MESP-T) test.

RESULTS

Children's tone recognition for tone pairs and individual tones improved significantly between 2 and 3 years post CI use, showing an increase in average tone recognition score from 73.2% to 81.8%, which was significantly higher than chance level (i.e. 50%). There was no significant correlation between tone recognition ability and either implant age or chronological age at two evaluation points. Further analysis revealed that the tone recognition score for tone pair 2-3 was significantly lower than that for other tone pairs except for tone pair 2-4.

CONCLUSIONS

Longer CI experience can significantly improve tone recognition ability in CI children between 2 and 3 years post CI activation.

Resting-state EEG reveals global network deficiency in prelingually deaf children with late cochlear implantation

There are individual differences in rehabilitation after cochlear implantation that can be explained by brain plasticity. However, from the perspective of brain networks, the effect of implantation age on brain plasticity is unclear. The present study investigated electroencephalography functional networks in the resting state, including eyes-closed and eyes-open conditions, in 31 children with early cochlear implantation, 24 children with late cochlear implantation, and 29 children with normal hearing. Resting-state functional connectivity was measured with phase lag index, and we investigated the connectivity between the sensory regions for each frequency band. Network topology was examined using minimum spanning tree to obtain the network backbone characteristics. The results showed stronger connectivity between auditory and visual regions but reduced global network efficiency in children with late cochlear implantation in the theta and alpha bands. Significant correlations were observed between functional backbone characteristics and speech perception scores in children with cochlear implantation. Collectively, these results reveal an important effect of implantation age on the extent of brain plasticity from a network perspective and indicate that characteristics of the brain network can reflect the extent of rehabilitation of children with cochlear implantation.

Development of Mandarin Chinese Vowel Perception in Young Children With Normal Hearing and Cochlear Implants

Purpose Depicting the development pattern of vowel perception for children with normal hearing (NH) and cochlear implants (CIs) would be useful for clinicians and school teachers to monitor children's auditory rehabilitation. The study was to investigate the development of Mandarin Chinese vowel perception for Mandarin Chinese native-speaking children with the ages of 4-6 years. Method Vowel identification of children with NH and CIs were tested. All children with CIs received CIs before the age of 4 years. In a picture identification task with Mandarin Chinese speech stimuli, listeners identified the target consonant-vowel word among two to four contrastive words that differed only in vowels. Each target word represented a concrete object and was spoken by a young female native Mandarin Chinese talker. The target words included 16 monophthongs, 22 diphthongs, and nine triphthongs. Results Children with NH showed significantly better identification of monophthongs and diphthongs than children with CIs at the age of 6 years, whereas the two groups had comparable performance at age of 4 and 5 years. Children with NH significantly outperformed children with CIs for triphthong identification across all three age groups. For children with NH, a rapid development of perception of all three types of vowels occurred between age 4 and 5 years with a rapid development only for monophthong perception between age 5 and 6 years. For children with CIs, a rapid development of both diphthong and triphthong perception occurred between 4 and 5 years old, but not monophthong, with no significant development between 5 and 6 years old for all three types of vowels. Overall, Mandarin-speaking children with NH achieved their ceiling performance in vowel perception before or at the age of 6 years, whereas children with CIs may need more time to reach the typical level of their peers with NH. Conclusions The development of Mandarin vowel perception for Mandarin-native children differed between preschool-age children with NH and CIs, likely due to the deficits of spectral processing for children with CIs. The results would be a supplement to the development of speech recognition in Mandarin-native children with NH and CIs.

Effects of Fundamental Frequency Contours on Sentence Recognition in Mandarin-Speaking Children With Cochlear Implants

Purpose Fundamental frequency (F0) is the primary acoustic cue for lexical tone perception in tonal languages but is processed in a limited way in cochlear implant (CI) systems. The aim of this study was to evaluate the importance of F0 contours in sentence recognition in Mandarin-speaking children with CIs and find out whether it is similar to/different from that in age-matched normal-hearing (NH) peers. Method Age-appropriate sentences, with F0 contours manipulated to be either natural or flattened, were randomly presented to preschool children with CIs and their age-matched peers with NH under three test conditions: in quiet, in white noise, and with competing sentences at 0 dB signal-to-noise ratio. Results The neutralization of F0 contours resulted in a significant reduction in sentence recognition. While this was seen only in noise conditions among NH children, it was observed throughout all test conditions among children with CIs. Moreover, the F0 contour-induced accuracy reduction ratios (i.e., the reduction in sentence recognition resulting from the neutralization of F0 contours compared to the normal F0 condition) were significantly greater in children with CIs than in NH children in all test conditions. Conclusions F0 contours play a major role in sentence recognition in both quiet and noise among pediatric implantees, and the contribution of the F0 contour is even more salient than that in age-matched NH children. These results also suggest that there may be differences between children with CIs and NH children in how F0 contours are processed.

The characteristics of social maturity in infants and children with cochlear implants in China

OBJECTIVE

The primary aim of the current study was to examine the social maturity of infants and children with cochlear implants in China. A secondary aim was to document the associated information using a General Condition Questionnaire for further cohort study in this population.

MATERIALS AND METHODS

This is a retrospective cross-sectional observational study and a pilot study. Between July and December 2017, data from all implantees between the ages of 6 months and 14 years who presented to the Hearing and Speech Center of Shanghai Ninth People's Hospital for mapping were collected. There were 119 non-overlapping cases in total. Data were collected via the Infants-Junior Middle School Students' Social-Life Abilities Scale (S-M scale) and a structured General Condition Questionnaire. The S-M scale was used for social adaptability measurement for children aged between 6 months to 14 yearsold. The General Condition Questionnaire, which was completed by the parents or primary caregivers of the implantees, gathered 3 aspects of personal information: the patient's history of hearing loss, personal history of rehabilitation and their past medical history.

RESULTS

Results showed that in 119 cases, 89 implantees (74.8%) were at or above a normal social maturity level. Thirty implantees (25.2%) scored lower than normal on the S-M standard score. Spearman's rank correlation indicated that the age at which hearing loss was noticed, the age of initial rehabilitation and the age at implantation were significantly correlated with the patients' scores on the S-M scale.

CONCLUSION

In summary, most of the cochlear implantees showed normal social maturity, with the exception of 25.2% of implantees who performed at a lower level than their normal hearing peers. These findings suggest potential targets to investigate in future cohort studies in cochlear implantees.

Processing of Acoustic Information in Lexical Tone Production and Perception by Pediatric Cochlear Implant Recipients

Purpose: This study examined the utilization of multiple types of acoustic information in lexical tone production and perception by pediatric cochlear implant (CI) recipients who are native speakers of Mandarin Chinese. Methods: Lexical tones were recorded from CI recipients and their peers with normal hearing (NH). Each participant was asked to produce a disyllabic word, yan jing, with which the first syllable was pronounced as Tone 3 (a low dipping tone) while the second syllable was pronounced as Tone 1 (a high level tone, meaning "eyes") or as Tone 4 (a high falling tone, meaning "eyeglasses"). In addition, a parametric manipulation in fundamental frequency (F0) and duration of Tones 1 and 4 used in a lexical tone recognition task in Peng et al. (2017) was adopted to evaluate the perceptual reliance on each dimension. Results: Mixed-effect analyses of duration, intensity, and F0 cues revealed that NH children focused exclusively on marking distinct F0 contours, while CI participants shortened Tone 4 or prolonged Tone 1 to enhance their contrast. In line with these production strategies, NH children relied primarily on F0 cues to identify the two tones, whereas CI children showed greater reliance on duration cues. Moreover, CI participants who placed greater perceptual weight on duration cues also tended to exhibit smaller changes in their F0 production. Conclusion: Pediatric CI recipients appear to contrast the secondary acoustic dimension (duration) in addition to F0 contours for both lexical tone production and perception. These findings suggest that perception and production strategies of lexical tones are well coupled in this pediatric CI population.

The effects of narrative-based language intervention (NBLI) on spoken narrative structures in Persian-speaking cochlear implanted children: A prospective randomized control trial

BACKGROUND

Previous research has shown that narrative-based language intervention (NBLI) is a feasible approach increasing the narrative skills of hearing-impaired children.

OBJECTIVE

In the present study, the efficacy of NBLI on the macrostructure and microstructure components of the spoken narrative of children with cochlear implants (CI) was evaluated in an experimental study.

MATERIALS AND METHODS

Thirty-six CI children between the ages of 5.5 and 7 years were randomly divided in three groups of equal size. Group 1 attended 24 1-h sessions of NBLI group therapy. Group 2 participants each attended 24 1-h private sessions of NBLI instruction. Group 3 attended 24 1-h conventional speech therapy (CST) sessions. The subjects' storytelling skills were prompted using pictures from the Persian version of the Language Sample Analysis test. The results were assessed before treatment (T0), after treatment (T1) and two months after treatment (T2) as follow-up.

RESULTS

Groups 1 and 2 showed significantly better results over Group 3 on all microstructure components of spoken narrative at the T1 (p ≤ 0.04) and T2 (p ≤ 0.04) levels in comparison with T0, but no differences were observed between the NBLI approaches (p > 0.05). All three intervention programs significantly improved the macrostructure of the spoken narrative in CI children.

CONCLUSION

Improvements in spoken narrative structures were observed in CI children that support the efficacy of NBLI over CST for the hearing-impaired population.

The Benefits of Residual Hair Cell Function for Speech and Music Perception in Pediatric Bimodal Cochlear Implant Listeners

Objective

The aim of this study was to investigate the benefits of residual hair cell function for speech and music perception in bimodal pediatric Mandarin-speaking cochlear implant (CI) listeners.

Design

Speech and music performance was measured in 35 Mandarin-speaking pediatric CI users for unilateral (CI-only) and bimodal listening. Mandarin speech perception was measured for vowels, consonants, lexical tones, and sentences in quiet. Music perception was measured for melodic contour identification (MCI).

Results

Combined electric and acoustic hearing significantly improved MCI and Mandarin tone recognition performance, relative to CI-only performance. For MCI, performance was significantly better with bimodal listening for all semitone spacing conditions (p < 0.05 in all cases). For tone recognition, bimodal performance was significantly better only for tone 2 (rising; p < 0.05). There were no significant differences between CI-only and CI + HA for vowel, consonant, or sentence recognition.

Conclusions

The results suggest that combined electric and acoustic hearing can significantly improve perception of music and Mandarin tones in pediatric Mandarin-speaking CI patients. Music and lexical tone perception depends strongly on pitch perception, and the contralateral acoustic hearing coming from residual hair cell function provided pitch cues that are generally not well preserved in electric hearing.

Assessment of narrative writing by Persian-speaking students with hearing impairments

OBJECTIVE

Previous studies have highlighted that narrative skill is critical to the development of the literacy skills by children. Children with cochlear implants (CI) and hearing aids (HA) may have problems in narrative development compared to peers with healthy hearing (HH). There is no exact data about the narrative writing ability of Persian-speaking students who are hearing-impaired. This study was undertaken to compare the microstructure and macrostructure scores for narrative writing of Persian-speaking students who are hearing-impaired and peers with HH.

DESIGN

This was a cross-sectional descriptive-analytical study.

SETTING

The subjects were recruited from elementary schools in the city of Tehran.

PARTICIPANTS

A total of 144 elementary school students were participated.

OUTCOME MEASURES

The written narratives were elicited using a wordless pictorial storybook story. Three-way ANOVA with post hoc adjusted Bonferroni test was applied to determine the main effects and interactions of grounded variables on the microstructure and macrostructure components of narrative writing.

RESULTS

No significant differences were observed in the macrostructure components of narrative writing between hearing-impaired and HH students. Factors analysis showed that the 4th grade HH students had significantly the highest scores, and the 3rd grade HA students had significantly the lowest scores in microstructure components of narrative writing.

CONCLUSION

The findings revealed that hearing-impaired students similarly to their HH peers can transmit the main idea (macrostructure) of narrative writing, but show critical difficulties when using complete grammatical elements (microstructures) to form sentences to convey the idea in the narrative.

Cantonese Tone Perception for Children Who Use a Hearing Aid and a Cochlear Implant in Opposite Ears

OBJECTIVES

The ability to recognize tones is vital for speech perception in tonal languages. Cantonese has six tones, which are differentiated almost exclusively by pitch cues (tones 1 to 6). The differences in pitch contours among the tones are subtle, making Cantonese a challenging language for cochlear implant users. The addition of a hearing aid has been shown to improve speech perception in nontonal languages and in Mandarin Chinese. This study (1) investigates the Cantonese tone perception ability of children who use a cochlear implant and a hearing aid in opposite ears; (2) evaluates the effect of varying pitch height and pitch contour cues on Cantonese tone perception for these children; and (3) compares the Cantonese tone perception ability for using a hearing aid and a cochlear implant together versus an implant alone.

DESIGN

Eight native Cantonese speaking children using a cochlear implant and a hearing aid in opposite ears were assessed for tone perception and word identification. The tone perception test involved discriminating and ranking tone pairs from natural and artificially manipulated Cantonese tones with various pitch heights and/or pitch contours. The word identification test involved identifying Cantonese words in a four-alternative forced-choice task. All tests were performed in two device conditions: (1) cochlear implant and hearing aid together and (2) implant alone.

RESULTS

Seven of the 8 subjects performed significantly above chance in both tests using the cochlear implant alone. Results showed that both pitch height and/or pitch direction were important perceptual cues for implant users. Perception for some tones was improved by increasing the pitch height differences between the tones. The ability to discriminate and rank the tone 2/tone 5 contrast and the tone 4/tone 6 contrast was poor, as the tones in these contrasts are similar in pitch contours and onset frequencies. No significant improvement was observed after artificially increasing the pitch offset differences between the tones in the tone 2/tone 5 and the tone 4/tone 6 contrasts. Tone perception results were significantly better with the addition of the hearing aid in the nonimplanted ear compared with using the implant alone; however, word identification results were not significantly different between using the implant alone and using both the hearing aid and the implant together. None of the subjects performed worse in tone perception or in word identification when the hearing aid was added.

CONCLUSIONS

Reduced ability to perceive pitch contour cues, even when artificially exaggerated, may explain some of the difficulties in Cantonese word recognition for implant users. The addition of a contralateral hearing aid could be beneficial for Cantonese tone perception for some individuals with a unilateral implant. The results encouraged Cantonese speakers to trial a hearing aid in the nonimplanted ear when using a cochlear implant.

Processing of Acoustic Cues in Lexical-Tone Identification by Pediatric Cochlear-Implant Recipients

PURPOSE

The objective was to investigate acoustic cue processing in lexical-tone recognition by pediatric cochlear-implant (CI) recipients who are native Mandarin speakers.

METHOD

Lexical-tone recognition was assessed in pediatric CI recipients and listeners with normal hearing (NH) in 2 tasks. In Task 1, participants identified naturally uttered words that were contrastive in lexical tones. For Task 2, a disyllabic word (yanjing) was manipulated orthogonally, varying in fundamental-frequency (F0) contours and duration patterns. Participants identified each token with the second syllable jing pronounced with Tone 1 (a high level tone) as eyes or with Tone 4 (a high falling tone) as eyeglasses.

RESULTS

CI participants' recognition accuracy was significantly lower than NH listeners' in Task 1. In Task 2, CI participants' reliance on F0 contours was significantly less than that of NH listeners; their reliance on duration patterns, however, was significantly higher than that of NH listeners. Both CI and NH listeners' performance in Task 1 was significantly correlated with their reliance on F0 contours in Task 2.

CONCLUSION

For pediatric CI recipients, lexical-tone recognition using naturally uttered words is primarily related to their reliance on F0 contours, although duration patterns may be used as an additional cue.

Mandarin Lexical Tone Acquisition in Cochlear Implant Users With Prelingual Deafness: A Review

PURPOSE

The purpose of this review article is to synthesize evidence from the fields of developmental linguistics and cochlear implant technology relevant to the production and perception of Mandarin lexical tone in cochlear implant users with prelingual deafness. The aim of this review was to identify potential factors that determine outcomes for tonal-language speaking cochlear implant users and possible directions for further research.

METHOD

A computerized database search of MEDLINE, CINAHL, Academic Search Premier, Web of Science, and Google Scholar was undertaken in June and July 2014. Search terms used were lexical tone AND tonal language, speech development AND/OR speech production AND/OR speech perception AND cochlear implants, and pitch perception AND cochlear implants, anywhere in the title or abstract.

CONCLUSION

Despite the demonstrated limitations of pitch perception in cochlear implant users, there is some evidence that typical production and perception of lexical tone is possible by cochlear implant users with prelingual deafness. Further studies are required to determine the factors that contribute to better outcomes to inform rehabilitation processes for cochlear implant users in tonal-language environments.

Pitch and lexical tone perception of bilingual English-Mandarin-speaking cochlear implant recipients, hearing aid users, and normally hearing listeners

OBJECTIVES

The purpose of this current study was to investigate whether pitch, lexical tone, and/or speech-in-noise perception were significantly correlated for Singaporean teenagers or adults who spoke both Mandarin and English.

METHODS

Thirty-three normal hearing or near-normal hearing listeners who did not use a hearing device (NNH group), eight postlingually deafened cochlear implant (CI) recipients (CI group), and three postlingually deafened bilateral hearing aid (HA) users (HA group) were recruited. All participants were bilingual Mandarin-English-speaking Singaporean residents. Participants were assessed on tests of pitch-ranking, lexical tone perception, and speech-in-noise.

RESULTS

The NNH group scored significantly better than the CI group for all tests and subtests. There were no significant differences for the pitch test between the HA group and either the CI or NNH group. However, HA users scored significantly better than the CI group, and more aligned with the NNH group's scores for both the lexical tone and Mandarin speech-in-noise test. There were highly significant moderate positive correlations between all three tests. Discussion Overall, the performance of the CI users in this study indicates that CI recipients still struggle on pitch-related auditory perception tasks. Additionally, although the test scores from the HA users were better than the CI recipients, they were not as good as the NNH listeners. The significant moderate correlations between all three tests indicate that there is at least some degree of overlap in the skills required to accurately perceive these stimuli.

CONCLUSION

The overall results suggest that CI users, and to a lesser extent HA users, still struggle with complex auditory perceptual tasks, particularly when it requires the perception of pitch. However, it may be possible that training one of these skills (e.g. musical pitch) may then generalize to other tasks (e.g. lexical tone and/or speech-in-noise). This is important for counseling, as well as for planning effective rehabilitation programs.

Objective and subjective evaluations of the Nurotron Venus cochlear implant system via animal experiments and clinical trials

CONCLUSION

This study described objective and subjective evaluations of the Nurotron® Venus™ Cochlear Implant System and indicated that this system produced a satisfactory performance.

OBJECTIVE

To observe the performance of the Nurotron® Venus™ cochlear implant (CI) system via electrophysiological and psychophysical evaluations.

METHODS

A 26-electrode CI system was specially designed. The performance of MRI in animal and cadaveric head experiments, EABR in cats experiment, the correlation between ESRT and C level, and psychophysics evaluations in clinical trials were observed.

RESULTS

In the animal and cadaveric head experiments, magnet dislocation could not be prevented in the 1.5 T MRI without removal of the internal magnet. The EABR was clearly elicited in cat experiment. In the clinical trial, the ESRT was strongly correlated with C level (p < 0.001). The human clinical trial involving 57 post-lingually deafened native Mandarin-speaking patients was performed. Residual hearing protection in the implanted ear at each audiometric frequency was observed in 27.5-46.3% patients post-operatively. A pitch ranking test revealed that place pitches were generally ordered from apical to basal electrodes. The recognitions of the perceptions of 301 disyllabic words, environment sounds, disyllabic words, and numerals were significantly better than the pre-operative performance and reached plateaus.

Speech performance in pediatric users of Nurotron ® Venus™ cochlear implants

OBJECTIVES

The primary purpose of this study was to investigate the longitudinal speech performance over 3 years in pediatric users of the Nurotron(®) cochlear implant system. The secondary purpose was to compare the speech performances of younger and older children with cochlear implants (CIs).

METHODS

The Mandarin Early Speech Perception (MESP), Meaningful Use of Speech Scale (MUSS), and Putonghua Chinese Communicative Development Inventory (PCDI) were used to evaluate speech performance of 22 Mandarin-speaking pediatric CI users throughout the first 36 months post-implantation. The subjects were grouped according to the age at implantation, i.e., younger CI group (<3 years) and older CI group (>3 years).

RESULTS

All the subjects demonstrated improvement in speech performance throughout the first 3 years of implant use with mean scores reaching the maximum performance at 36 months post-implantation. The median categories of MESP increased from 0.23 pre-implantation to 5.57 three years post-implantation. Likewise, the median percentage of MUSS was 5.57% to 73.75%; the median performance of PCDI was 55 to 400 for PCDI-comprehension and 32 to 384 for PCDI-production at the same interval. At nearly all test intervals, the older group performed better than the younger group except 24 months post-implantation, at which the MUSS score of the younger CI group was higher than that of the older CI group.

CONCLUSION

The children with Nurotron(®) Venus™ CI system showed considerable gains in speech and language development including tone performance which improved with hearing age. Earlier implantations haven't presented significantly positive performances until 24 months post-implantation in all the tests.

Mandarin speech perception in combined electric and acoustic stimulation

For deaf individuals with residual low-frequency acoustic hearing, combined use of a cochlear implant (CI) and hearing aid (HA) typically provides better speech understanding than with either device alone. Because of coarse spectral resolution, CIs do not provide fundamental frequency (F0) information that contributes to understanding of tonal languages such as Mandarin Chinese. The HA can provide good representation of F0 and, depending on the range of aided acoustic hearing, first and second formant (F1 and F2) information. In this study, Mandarin tone, vowel, and consonant recognition in quiet and noise was measured in 12 adult Mandarin-speaking bimodal listeners with the CI-only and with the CI+HA. Tone recognition was significantly better with the CI+HA in noise, but not in quiet. Vowel recognition was significantly better with the CI+HA in quiet, but not in noise. There was no significant difference in consonant recognition between the CI-only and the CI+HA in quiet or in noise. There was a wide range in bimodal benefit, with improvements often greater than 20 percentage points in some tests and conditions. The bimodal benefit was compared to CI subjects’ HA-aided pure-tone average (PTA) thresholds between 250 and 2000 Hz; subjects were divided into two groups: “better” PTA (<50 dB HL) or “poorer” PTA (>50 dB HL). The bimodal benefit differed significantly between groups only for consonant recognition. The bimodal benefit for tone recognition in quiet was significantly correlated with CI experience, suggesting that bimodal CI users learn to better combine low-frequency spectro-temporal information from acoustic hearing with temporal envelope information from electric hearing. Given the small number of subjects in this study (n = 12), further research with Chinese bimodal listeners may provide more information regarding the contribution of acoustic and electric hearing to tonal language perception.

Mandarin lexical tones identification among children with cochlear implants or hearing aids

OBJECTIVES

Mandarin Chinese is a lexical tone language that has four tones, with a change in tone denoting a change in lexical meaning. There are few studies regarding lexical tone identification abilities in deafened children using either cochlear implants (CIs) or hearing aids (HAs). Furthermore, no study has compared the lexical tone identification abilities of deafened children with their hearing devices turned on and off. The present study aimed to investigate the lexical tone identification abilities of deafened children with CIs or HAs.

METHODS

Forty prelingually deafened children (20 with CIs and 20 with HAs) participated in the study. In the HA group, 20 children were binaurally aided. In the CI group, all of the children were unilaterally implanted. All of the subjects completed a computerized lexical tone pairs test with their hearing devices turned on and off. The correct answers of all items were recorded as the total score and the correct answers of the tone pairs were recorded as subtotal scores.

RESULTS

No significant differences in the tone pair identification scores were found between the CI group and HA group either with the devices turned on or off (t=1.62, p=0.11; t=1.863, p=0.07, respectively). The scores in the aided condition were higher than in the unaided condition regardless of the device used (t=22.09, p<0.001, in the HA group; t=20.20, p<0.001, in the CI group). Significantly higher scores were found in the tone pairs that contained tone 4. Age at fitting of the devices was correlated with tone identification abilities in both the CI and HA groups. Other demographic factors were not correlated with tone identification ability.

CONCLUSIONS

The hearing device, whether a hearing aid or cochlear implant, is beneficial for tone identification. The lexical tone identification abilities were similar regardless of whether the subjects wore a HA or CI. Lexical tone pairs with different durations and dissimilar tone contour patterns are more easily identified. Receiving devices at earlier age tends to produce better lexical tone identification abilities in prelingually deafened children.

Auditory performance and speech intelligibility of Mandarin-speaking children implanted before age 5

OBJECTIVES

(1) To report the auditory performance and speech intelligibility of 84 Mandarin-speaking prelingually deaf children after using cochlear implants (CIs) for one, two, three, four, and five years to understand how many years of implant use were needed for them to reach a plateau-level performance; (2) to investigate the relation between subjective rating scales and objective measurements (i.e., speech perception tests); (3) to understand the effect of age at implantation on auditory and speech development.

METHODS

Eighty-four children with CIs participated in this study. Their auditory performance and speech intelligibility were rated using the Categorical Auditory Performance (CAP) and the Speech Intelligibility Rating (SIR) scales, respectively. The evaluations were made before implantation and six months, one, two, three, four, and five years after implantation. At the fifth year after implantation, monosyllabic-word, easy-sentence, and difficult-sentence perception tests were administered.

RESULTS

The median CAP score reached a plateau at category 6 after three years of implant use. The median SIR arrived at the highest level after five years of use. With five years of CI experiences, 86% of the subjects understood conversation without lip-reading, and 58% were fully intelligible to all listeners. The three speech perception tests had a moderate-to-strong correlation with the CAP and SIR scores. The children implanted before the age of three years had significantly better CAP and monosyllabic word perception test scores.

CONCLUSIONS

Five years of follow-up are needed for assessing the post-implantation development of communication ability of prelingually deafened children. It is recommended that hearing-impaired children receive cochlear implantation at a younger age to acquire better auditory ability for developing language skills. Constant postoperative aural-verbal rehabilitation and speech and language therapy are most likely required for the patients to reach the highest level on the CAP and SIR scales.

Mandarin consonant contrast recognition among children with cochlear implants or hearing aids and normal-hearing children

HYPOTHESIS

The purpose of the present study was to investigate the consonant recognition of Mandarin-speaking children with cochlear implants (CIs) and hearing aids (HAs) and to determine if they reach a level of consonant recognition similar to that of normal-hearing (NH) children.

BACKGROUND

Little information is available in the literature regarding the consonant perception abilities of prelingually deafened young children with either CIs or HAs. No studies have compared Mandarin-Chinese consonant contrast recognition in CI and HA children.

METHODS

Forty-one prelingually deafened children with CIs, 26 prelingually deafened children with HAs, and 30 NH children participated in this study. The 3 groups were matched for chronologic age (3-5 yr). The hearing-impaired groups were matched for age at fitting of the devices, duration of device use, and aided hearing threshold. All subjects completed a computerized Mandarin consonant phonetic contrast perception test.

RESULTS

CI and HA children scored, on average, approximately 8 percentage points below the mean NH group performance on the consonant contrast recognition. Approximately 40% of the CI and HA children had not reached a performance level of the NH group. No significant differences in the consonant recognition scores were found between the CI and HA groups. Age of implantation was correlated with consonant contrast recognition in the CI group.

CONCLUSION

When age at fitting of the devices, duration of device use, and aided thresholds are matched at the group level, consonant recognition is similar between the CI and HA children after 2 years of device use. Early implantation tends to yield better consonant contrast recognition in the young children with CIs. However, a large amount of variance in performance was not accounted for by the demographic variables studied.

The Effect of Cochlear Implantation on the Improvement of the Auditory Performance in 2-7 Years old Children, Shiraz 2004-2008

Background

Hearing loss is the most common sensorineural deficiency in human beings. Cochlear implantation is introduced worldwide to treat the severe to profound sensorineural hearing loss, and can result in both speech comprehension and production.

Objectives

The present study aims to determine the effect of cochlear implantation on the improvement of the auditory performance in 2-7 years old children.

Patients and Methods

The present follow-up study is a kind of cohort study which was conducted on 98 children between 2-7 years old who had referred to Fars Cochlear Implantation Center. The patients’ information was gathered from their profiles both before and after the operation. The auditory performance score was obtained in 3 stages; 6 months, 1 year, and 2 years after the cochlear implantation through the Cap test. The data was analyzed using the nonparametric Friedman test as well as Mann-Withney, Kruskal-Wallis, and Spearman's Ranks Correlation coefficients.

Results

The mean and the median of the auditory performance score of the children who had undergone the cochlear implantation revealed a significant improvement from 6 months to 1 year, and 2 years after the implantation. It showed a significant statistical association between implantation age, type of hearing loss, regular reference, and the length of being present in the rehabilitation program with the auditory performance. It showed no significant association between sex, mother’s level of education, being monolingual or bilingual, and family size with the auditory performance.

Conclusions

This study revealed that the type of hearing loss, Presence in the rehabilitation program, and the age of cochlear implantation can be major prognostic factors of the response to the treatment, then the country’s health policy makers and health planners must executively take into account the infants’ hearing screening program during the first 6 month of age.

Development and validation of the Mandarin disyllable recognition test

CONCLUSION

Given the phonetic balancing across lists and the validation with spectrally degraded speech, the present Mandarin disyllable recognition test (DRT) materials may be useful for assessing speech performance of Mandarin-speaking cochlear implant (CI) users. If combined with the previously developed sentence materials, these materials would help to establish standardized speech perception tests for Mandarin-speaking hearing-impaired (HI) and CI patients.

OBJECTIVES

To develop standardized Mandarin DRT materials that can be used to evaluate the speech performance of Mandarin-speaking HI and CI patients, and to establish standardized Mandarin speech perception test materials that include both disyllables and sentences.

METHODS

Ten phonetically balanced Mandarin DRT lists were developed. The DRT materials were validated in 8 normal-hearing (NH) subjects listening to unprocessed speech and in 10 NH subjects listening to a 4-channel, sine-wave vocoded acoustic simulation of CI speech processing. Performance with the DRT materials was compared to that with Mandarin sentence materials previously developed by our group.

RESULTS

The distribution of vowels, consonants, and tones within each DRT list was similar to that observed across commonly used Chinese characters. There was no significant difference in disyllable word recognition across lists in both unprocessed and four-channel vocoded speech. There was a significant correlation between disyllable and sentence recognition performance.

Comparison of Mandarin tone and speech perception between advanced combination encoder and continuous interleaved sampling speech-processing strategies in children

OBJECTIVE

This study was performed to compare cochlear implant (CI) users' performance in Mandarin speech and tone perception between 2 types of speech-processing strategies-advanced combination encoder (ACE) and continuous interleaved sampling (CIS)-under quiet and noisy conditions.

METHODS

This study involved 10 congenitally deaf children (age range, 5.7-15.3 years; mean, 9.2 years) who received the Nucleus 24-channel CI system cochlear device (CI24R; Cochlear Ltd, Lane Cove NSW, Australia). The subjects used ACE since switching on their CI devices. Speech and tone perception tests were administered under quiet and noisy (+5 dB signal-to-noise ratio) conditions with ACE and CIS strategies 20 minutes and 2 weeks apart.

RESULTS

Regardless of the strategy used, subjects showed significantly higher scores in speech perception than in tone recognition. Under noisy conditions, subjects had significantly higher tone identification scores with the CIS than the ACE strategy (P = .038). There was no significant difference in speech identification score between the strategies. Subjects showed significant higher tone identification and speech perception scores under quiet than noisy (+5 dB signal-to-noise ratio) conditions. Subjectively, 6 subjects preferred the ACE strategy, and the remaining 4 preferred the CIS strategy. The strategy preference of the subjects was related to speech perception performance rather than tone identification. A significant correlation was observed between tone identification and speech recognition, regardless of whether speech was evaluated by consonants (r = 0.669, P < .001), vowels (r = 0.426, P = .001), or sentences (r = 0.294, P = .023).

CONCLUSION

There are only 4 patterns of tone in Mandarin, which is far fewer than the number of speech sounds. However, tone identification is poorer than speech perception. The CIS speech-processing strategy may improve tone identification under noisy conditions. Before improved speech strategies to code acoustic characteristics of tone can be developed, it would be worthwhile to try both CIS and ACE for CI users and to select the most suitable speech-processing strategy according to the subjective preference and objective performance.

Contribution of a contralateral hearing aid to perception of consonant voicing, intonation, and emotional state in adult cochlear implantees

Binaural hearing in cochlear implant (CI) users can be achieved either by bilateral implantation or bimodally with a contralateral hearing aid (HA). Binaural-bimodal hearing has the advantage of complementing the high-frequency electric information from the CI by low-frequency acoustic information from the HA. We examined the contribution of a contralateral HA in 25 adult implantees to their perception of fundamental frequency-cued speech characteristics (initial consonant voicing, intonation, and emotions). Testing with CI alone, HA alone, and bimodal hearing showed that all three characteristics were best perceived under the bimodal condition. Significant differences were recorded between bimodal and HA conditions in the initial voicing test, between bimodal and CI conditions in the intonation test, and between both bimodal and CI conditions and between bimodal and HA conditions in the emotion-in-speech test. These findings confirmed that such binaural-bimodal hearing enhances perception of these speech characteristics and suggest that implantees with residual hearing in the contralateral ear may benefit from a HA in that ear.

Audiologic management of auditory neuropathy spectrum disorder in children: a systematic review of the literature

PURPOSE

This review summarizes current evidence related to the audiologic management of children with auditory neuropathy spectrum disorder (ANSD).

METHOD

A systematic search of the literature was conducted in 25 electronic databases (e.g., PubMed, CINAHL, and ERIC) using key words such as auditory neuropathy, auditory neuropathy spectrum disorder, auditory neuropathy/dyssynchrony, and hearing loss. Eighteen studies met the inclusion criteria by addressing 1 or more of 8 clinical questions. Studies were evaluated for methodological quality, and data regarding participant, intervention, and outcome variables are reported.

RESULTS

Fifteen of the 18 studies addressed the use of cochlear implantation, and 4 addressed conventional acoustic amplification. All participants demonstrated improved auditory performance; however, all 18 studies were considered exploratory, and many had methodological limitations.

CONCLUSION

The clinical evidence related to intervention for ANSD is at a very preliminary stage. Additional research is needed to address the efficacy of acoustic amplification and cochlear implantation in children with ANSD and the impact of this disorder on developmental outcomes.

Acoustic characteristics of vowels and plosives/affricates of Mandarin-speaking hearing-impaired children

This article presents the results of an acoustic analysis of vowels and plosives/affricates produced by 45 Mandarin-speaking children with hearing impairment. Vowel production is represented and categorized into three groups by vowel space size calculated with normalized F1 and F2 values of corner vowels. The correlation between speech intelligibility and language abilities assessed by the level of word comprehension and the complexity of sentence structure is statistically significant. Vowel space grouping is correlated with speech intelligibility and spike percentage of plosives/affricates production. The generalized linear model analysis also shows that the level of word comprehension and the degree of hearing loss are the two most significant factors in predicting speech intelligibility. The statistical results suggest that the interplay of acoustic characteristic and speech ability is complex.

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.

Long-term language levels and reading skills in mandarin-speaking prelingually deaf children with cochlear implants

The aim of this study was to document receptive and expressive language levels and reading skills achieved by Mandarin-speaking children who had received cochlear implants (CIs) and used them for 4.75-7.42 years. The effects of possible associated factors were also analyzed. Standardized Mandarin language and reading tests were administered to 39 prelingually deaf children with Nucleus 24 devices. The Mandarin Chinese version of the Peabody Picture Vocabulary Test was used to assess their receptive vocabulary knowledge and the Revised Primary School Language Assessment Test for their receptive and expressive language skills. The Graded Chinese Character Recognition Test was used to test their written word recognition ability and the Reading Comprehension Test for their reading comprehension ability. Raw scores from both language and reading measurements were compared to normative data of nor- mal-hearing children to obtain standard scores. The results showed that the mean standard score for receptive vocabulary measurement and the mean T scores for the receptive language, expressive language and total language measurement were all in the low-average range in comparison to the normative sample. In contrast, the mean T scores for word and text reading comprehension were almost the same as for their age-matched hearing counterparts. Among all children with CIs, 75.7% scored within or above the normal range of their age-matched hearing peers on receptive vocabulary measurement. For total language, Chinese word recognition and reading scores, 71.8, 77 and 82% of children with CIs were age appropriate, respectively. A strong correlation was found between language and reading skills. Age at implantation and sentence perception scores account for 37% of variance for total language outcome. Sentence perception scores and preimplantation residual hearing were revealed to be associated with the outcome of reading comprehension. We concluded that by using standard tests, the language development and reading skill of Mandarin-speaking children who use CIs from a young age appear to fall within the normal range of their hearing age mates, at least after 4.8-7.4 years of experience. However, to fully evaluate the fine linguistic skills of these subjects, a more detailed study and longer follow-up period are needed.

Lexical tone perception with HiResolution and HiResolution 120 sound-processing strategies in pediatric Mandarin-speaking cochlear implant users

OBJECTIVES

Lexical tone recognition tends to be poor in cochlear implant users. The HiResolution (HiRes) sound-processing strategy is designed to better preserve temporal fine structure, or the detailed envelope information, of an acoustic signal. The newer HiRes 120 strategy builds on HiRes by increasing the amount of potential spectral information delivered to the implant user. The purpose of this study was to examine lexical tone recognition in native Mandarin Chinese-speaking children with cochlear implants using the HiRes and HiRes 120 sound-processing strategies. Tone recognition performance was tested with HiRes at baseline and then after up to 6 mo of HiRes 120 experience in the same subjects.

DESIGN

Twenty prelingually deafened, native Mandarin-speaking children, with ages ranging from 3.5 to 16.5 yr, participated. All children completed a computerized tone contrast test on three occasions: (1) using HiRes immediately before conversion to HiRes 120 (baseline), (2) 1 mo after conversion, and (3) 3 mo after conversion. Twelve of the 20 children also were tested 6 mo after conversion. In addition, the parents of 18 children completed a questionnaire at the 3-mo follow-up visit regarding the preference of sound-processing strategies and the children's experience related to various aspects of auditory perception and speech production using HiRes 120.

RESULTS

As a group, no statistically significant differences were seen between the tone recognition scores using HiRes and HiRes 120. Individual scores showed great variability. Tone recognition performance ranged from chance (50% correct) to nearly perfect. Using the conventional HiRes strategy, 6 of the 20 children achieved high-level tone recognition performance (i.e., >or=90% correct), whereas 7 performed at a level not significantly different from chance (50-60% correct). At the final test, either 3 or 6 mo after conversion, all children achieved tone recognition performance with HiRes 120 that was equal to or better than that with HiRes, although some children's tone recognition performance was worse initially at the 1 or 3 mo follow-up intervals than at baseline. Eight of the 20 children showed statistically significant improvement in tone recognition performance with HiRes 120 on at least one of the follow-up tests. Age at implantation was correlated with tone recognition performance at all four test intervals. Parents of most of the children indicated that the children preferred HiRes 120 more than HiRes.

CONCLUSIONS

As a group, HiRes 120 did not provide significantly improved lexical tone recognition compared to HiRes, at least throughout the length of the study (up to 6 mo). There were large individual differences in lexical tone recognition among the prelingually deafened, native Mandarin-speaking children with cochlear implants using either HiRes or HiRes 120. Six of the 20 children performed at or near ceiling in the baseline HiRes condition. Of the remainder, approximately half showed significantly better tone recognition when subsequently tested with HiRes 120, although the extent to which this improvement may be attributable to factors other than the change in processing strategy (e.g., general development) is unknown. The children who benefited most from HiRes 120 tended to be those who were implanted at younger ages.

Auditory, visual, and auditory-visual perception of emotions by individuals with cochlear implants, hearing AIDS, and normal hearing

This study evaluated the benefits of cochlear implant (CI) with regard to emotion perception of participants differing in their age of implantation, in comparison to hearing aid users and adolescents with normal hearing (NH). Emotion perception was examined by having the participants identify happiness, anger, surprise, sadness, fear, and disgust. The emotional content was placed upon the same neutral sentence. The stimuli were presented in auditory, visual, and combined auditory-visual modes. The results revealed better auditory identification by the participants with NH in comparison to all groups of participants with hearing loss (HL). No differences were found among the groups with HL in each of the 3 modes. Although auditory-visual perception was better than visual-only perception for the participants with NH, no such differentiation was found among the participants with HL. The results question the efficiency of some currently used CIs in providing the acoustic cues required to identify the speaker's emotional state.

What can be expected from a late cochlear implantation?

OBJECTIVE

Verify if late cochlear implantation allows pre-lingual deafs to convert from visual to oral communication mode only.

METHOD

Thirteen pre-lingual profoundly deaf patients implanted the ages of 8 and 22 years were included in the study. Before cochlear implantation, none of the patients used the oral language. Six patients used cued speech and seven used the sign language to communicate. Evaluations were made with measures of hearing thresholds, phoneme identification, categories of auditory performance and rating of the intelligibility of speech before and after implantation. Changes in principal mode of communication (i.e. oral, cued speech or sign language) were also monitored.

RESULTS

The former users of cued speech benefited significantly more from cochlear implantation than the sign language users for phoneme identification and categories of auditory performance, although all had similar hearing thresholds before and after cochlear implantation. After a mean implant use of 4.5 years, four out of six cued speech users converted to exclusive use of the oral language, while only one out of seven former users of the sign language converted to the use of the oral language.

DISCUSSION

It is possible for pre-lingual or congenital deafs to convert totally from a visual to an oral communication mode even in case of late cochlear implantation. Previous awareness of the structure of the oral language, even without hearing (e.g. via cued speech) influences positively the outcome of delayed implantations. We recommend the adoption of oral communication with the cued speech code in cases where a late cochlear implantation is envisioned.

Development and evaluation of methods for assessing tone production skills in Mandarin-speaking children with cochlear implants

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.

Pediatric cochlear implantation in Taiwan: long-term communication outcomes

OBJECTIVES/HYPOTHESIS

Cochlear implantation is an established method of auditory rehabilitation for severely and profoundly hearing impaired individuals. Although numerous studies have examined communication outcomes in pediatric cochlear implant (CI) recipients, data concerning the benefits of cochlear implantation in children who speak Mandarin Chinese are lacking. This study examined communication outcomes in 29 Mandarin-speaking children implanted at Chung Gung Memorial Hospital.

DESIGN

A prospective between-groups design was used to compare communication outcomes as a function of age at time of implantation.

METHODS

Children in the Younger group were implanted before 3 years of age, whereas children in the Older group were implanted after 3 years of age. Outcome measures assessed auditory thresholds, speech perception, speech intelligibility, receptive and expressive language skills, communication barriers, and communication mode. Correlation analysis was used to examine the relationship between communication outcome and age at implantation.

RESULTS

Children in the Younger group demonstrated a significant level of difference on Mandarin vowels, consonants, tones, and open-set speech perception compared with the children in the Older group. Between-group differences were also shown on receptive and expressive language skills. But, no significant differences were noted on speech intelligibility or in self-ratings of communication barriers. A larger proportion of children in the Younger group used oral communication and were educated in mainstream classrooms. Communication mode change of the Younger group reached a significant level after cochlear implant. Speech perception performance was negatively correlated with age at implantation as well as chronological age. Mandarin-speaking children can obtain substantial communication benefits from cochlear implantation, with earlier implantation yielding superior results.

Tone production of Mandarin Chinese speaking children with cochlear implants

OBJECTIVE

The purpose of the present study was to investigate tone production performance of native Mandarin Chinese speaking children with cochlear implants and to evaluate the effects of age at implantation and duration of implant use on tone production in those children.

METHODS

Fourteen prelingually deaf children who had received cochlear implantation and 14 age-matched normal-hearing children participated in the study. Both groups were of native Mandarin Chinese speaking children. One hundred and sixty tone tokens were recorded from each of the children. The total of 4480 tokens (160x28) were then used in the tone perception tests in which seven normal-hearing native Mandarin Chinese speaking adults participated.

RESULTS

The tone production of the cochlear implant children showed tremendous individual variability. The group mean performance was 48.4% correct, statistically significantly lower than the group mean performance of 78.0% correct in the normal-hearing controls. The tone confusion matrix analysis revealed that the production of Mandarin tone 2 (the rising tone) was most severely impaired in the cochlear implant children, followed by tone 3 (the low and dipping tone) and tone 4 (the falling tone). The most frequently perceived tone irrespective of the target tone was tone 1 (the high level tone). The tone production performance was negatively correlated with the age at implantation and positively correlated with the duration of implant use.

CONCLUSIONS

There is a remarkable deficit in tone production in a majority of native tone language speaking, prelingually deaf children who have received cochlear implants. While an increased duration of implant use might facilitate tone production, the age at implantation appears to have a negative effect on tone production in cochlear implant children. Therefore, early implantation might be beneficial to tone production in prelingually deaf children whose native language is a tone language.

Bilateral cochlear implants in children: localization acuity measured with minimum audible angle

OBJECTIVE

To evaluate sound localization acuity in a group of children who received bilateral (BI) cochlear implants in sequential procedures and to determine the extent to which BI auditory experience affects sound localization acuity. In addition, to investigate the extent to which a hearing aid in the nonimplanted ear can also provide benefits on this task.

DESIGN

Two groups of children participated, 13 with BI cochlear implants (cochlear implant + cochlear implant), ranging in age from 3 to 16 yrs, and six with a hearing aid in the nonimplanted ear (cochlear implant + hearing aid), ages 4 to 14 yrs. Testing was conducted in large sound-treated booths with loudspeakers positioned on a horizontal arc with a radius of 1.5 m. Stimuli were spondaic words recorded with a male voice. Stimulus levels typically averaged 60 dB SPL and were randomly roved between 56 and 64 dB SPL (+/-4 dB rove); in a few instances, levels were held fixed (60 dB SPL). Testing was conducted by using a "listening game" platform via computerized interactive software, and the ability of each child to discriminate sounds presented to the right or left was measured for loudspeakers subtending various angular separations. Minimum audible angle thresholds were measured in the BI (cochlear implant + cochlear implant or cochlear implant + hearing aid) listening mode and under monaural conditions.

RESULTS

Approximately 70% (9/13) of children in the cochlear implant + cochlear implant group discriminated left/right for source separations of <or=20 degrees , and, of those, 77% (7/9) performed better when listening bilaterally than with either cochlear implant alone. Several children were also able to perform the task when using a single cochlear implant, under some conditions. Minimum audible angle thresholds were better in the first cochlear implant than the second cochlear implant listening mode for nearly all (8/9) subjects. Repeated testing of a few individual subjects over a 2-yr period suggests that robust improvements in performance occurred with increased auditory experience. Children who wore hearing aids in the nonimplanted ear were at times also able to perform the task. Average group performance was worse than that of the children with BI cochlear implants when both ears were activated (cochlear implant + hearing aid versus cochlear implant + cochlear implant) but not significantly different when listening with a single cochlear implant.

CONCLUSIONS

Children with sequential BI cochlear implants represent a unique population of individuals who have undergone variable amounts of auditory deprivation in each ear. Our findings suggest that many but not all of these children perform better on measures of localization acuity with two cochlear implants compared with one and are better at the task than children using the cochlear implant + hearing aid. These results must be interpreted with caution, because benefits on other tasks as well as the long-term benefits of BI cochlear implants are yet to be fully understood. The factors that might contribute to such benefits must be carefully evaluated in large populations of children using a variety of measures.

Retrofacial approach of cochlear implantation in inner ear malformation with aberrant facial nerve: A case report

Cochlear implantation is regarded as a safe surgery for young children with minimal complications. However, inner ear malformations and aberrant course of facial nerves may impede electrode insertion via the round window approach and increase the risk of iatrogenic facial nerve injury. We report a case of cochlear incomplete partition in a patient with anomalous facial nerve anatomy. The anterior and inferior displacement of the facial nerve obscured the round window. A retrofacial approach was used to expose the round window and the electrode was inserted successfully. No surgical complications were found postoperatively, and the child showed significant improvement in speech perception. As the course of the aberrant facial nerve is difficult to track preoperatively, surgeons should proceed with caution to reduce the risk of facial nerve injury during the operation.

Effect of age at cochlear implantation on open-set word recognition in Mandarin speaking deaf children

OBJECTIVE

The purpose of this study was to determine whether age at cochlear implantation influences open-set speech perception in children after long-term use of the implant device.

METHOD

Twenty-eight congenitally deafened children, receiving implants of Nucleus CI24M devices, were divided into two groups: (1) CI < 3: those who received implants before 3 years of age and (2) CI > 3: those who received implants after 3 years of age. We compared open-set speech perception in CI < 3 and CI > 3 after 4-5 years of device use. Speech perception tests were conducted using the Mandarin Lexical Neighborhood Test (M-LNT). Unpaired t-test was applied for statistical analysis, and p < 0.05 was considered significant.

RESULTS

In CI < 3, the average of percent correct was 80.0 +/- 8.8 and 70.5 +/- 9.2% on, respectively, the easy and hard versions of the M-LNT. By contrast, in CI > 3, the average percent correct was 62.5 +/- 19.9 and 59.1 +/- 15.2%, respectively. Regardless of the M-LNT version used, CI < 3 performed significantly better than CI > 3 (easy, p = 0.005 versus hard, p = 0.022).

CONCLUSION

The present investigation demonstrated that age at implantation influences open-set speech perception of cochlear implanted children 4-5 years after device connection. Implantation before 3 years of age promotes the development of open-set speech perception abilities in congenitally deafened children.

Short electrode insertion in cochlear implantation: speech perception performance of Cantonese-speaking subjects

CONCLUSIONS

Subjects with cochlear ossification derived benefits in terms of speech performance similar to those of the non-ossified group. It is thus recommended that the insertion of short electrode arrays should be considered an alternative choice for patients with cochlear ossification.

OBJECTIVE

Cochlear ossification has been recognized as a major obstacle to the full insertion of a multichannel cochlear implant electrode array. To alleviate the technical difficulty of placing a standard electrode array and the possibility of causing undesirable trauma to the cochlea, a newly designed electrode array with the same number of electrodes compressed into a shorter length has been made available. The aim of the present study was to examine the speech perception performance of patients implanted with the MED-EL C40+S compressed electrode array and to compare their results with those of matched groups implanted with the MED-EL C40+standard electrode array.

MATERIAL AND METHODS

One pre-lingually and two post-lingually deaf subjects using short electrode arrays were matched with three groups of subjects using standard electrode arrays. The pre- and postoperative speech perception scores were evaluated.

RESULTS

All three subjects using compressed electrode arrays achieved speech perception scores comparable to those of matched subjects using standard electrode arrays. There was also a tendency for the subjects to show similar patterns of speech perception scores as a function of the difficulty of the tests.

Speech intelligibility of Mandarin-speaking deaf children with cochlear implants

OBJECTIVE

Speech intelligibility, the extent to which the speakers can be understood verbally by their listeners, is an evaluator for the effectiveness of cochlear implantation. Thus, our goals were to evaluate the result of a tonal language through comparing the speech intelligibility between normal-hearing and implanted children who speak Mandarin, and to evaluate the relationship between speech intelligibility and duration of implants use. The effects of the age at implantation were also evaluated.

METHODS

Twenty-six children (mean age of 5.9 years), who were congenitally deaf and implanted age at 3.5 years, were compared with 26 normal-hearing children (mean age of 5.84 years). The average post-implanted time was more than 6 months. Speech intelligibility was represented with the speech intelligibility ratings (SIR) and the correct percentage of dictation. The relationships between speech intelligibility, age at implantation and duration of implant were evaluated by linear regression analysis.

RESULTS

Speech intelligibility of most subjects ranked from SIR category 3-5. The average correct perception rate (CI group/normal group) of words, consonants, vowels, and tones were 42.5%, 64.9%, 73.5%, and 72.3%, respectively. These differences were statistically significant (p<0.001). Speech intelligibility was positively correlated with age only in the normal-hearing group. Speech intelligibility in the implanted group was negatively correlated with age at implantation but positively correlated with the duration of implant.

CONCLUSIONS

Speech intelligibility of tonal language was poorer in implanted children than normal-hearing children, but their communication outcomes were satisfactory when measured with SIR. Speech intelligibility is better if the age at implantation is younger or duration of implants use is longer.

Mandarin tone recognition in cochlear-implant subjects

This study examined tone recognition in five cochlear-implant subjects who were native speakers of Mandarin and used a Nucleus-22 device. Psychophysical experiments were conduced to measure rate discrimination in individual electrodes from the most apical to the most basal electrodes. The rate range was from 100 to 200 Hz, which corresponded to the range of variation in fundamental frequency for the tonal tokens used in this study. Speech recognition experiments were also conducted to measure tone recognition as function of the number of electrodes from a 1-electrode map to a 20-electrode map. Large individual variability was observed for both rate discrimination and tone recognition result: Average rate discrimination ranged between 0.2 and 1.2 (Weber's fraction) whereas tone recognition ranged between 30% and 70% correct. A highly significant correlation was found between rate discrimination and tone recognition with the 20-electrode map, but a non-significant correlation was observed with the 1-electrode map due to a floor effect in tone recognition. The present result supports the hypothesis that both spectral and temporal cues contribute to tone recognition. In addition, the present result shows that current cochlear-implant subjects produced significantly lower performance than acoustic simulations in normal-hearing subjects, suggesting that neither temporal nor spectral cues have been adequately and appropriately extracted and encoded in current cochlear implants. New designs are discussed to improve tone recognition in cochlear implant subjects.

The auditory performance in children using cochlear implants: effects of mental function

OBJECTIVE

Mental function is considered to affect the post-operative outcomes of deaf children with cochlear implants. The purpose of this study is to evaluate the effect of mental function on the auditory performance in children with cochlear implants.

METHODS

In a retrospective review of data, 26 pre-lingual deafened children received pre-operative evaluation of mental function and were divided into normal and retarded groups. Categories of auditory performance scale (CAP) was conducted at 1-year intervals after implantation. ANCOVA was used for statistic analysis.

RESULTS

The average scores of auditory performance in normal group (n=14) were 3.93 (S.D. 1.07) and 5.86 (S.D. 0.95) at 1- and 2-year post-implantation. While the average scores in the retarded group were 2.5 (S.D. 1.51) and 4.17 (S.D. 1.85), both groups demonstrated obvious improvement in speech perception (F 103.12, P<0.001) during the first 2 post-operative years. The auditory performance in the normal group was significantly superior to the retarded group (F 8.67, P<0.01). However, the interaction between the duration of the device use and mental status showed no significant difference in the auditory perception performance (F 1.575, P=0.222).

CONCLUSIONS

The results revealed the mental function plays as one of the predictive parameters of auditory performance in profoundly hearing impaired children after cochlear implantation.

Parental decision-making in considering cochlear implant technology for a deaf child

OBJECTIVES

Advances in cochlear implant (CI) technology have increased the complexity of treating childhood deafness. We compare parental decision-making, values, beliefs, and preferences between parents of eligible and ineligible children in considering cochlear implants.

METHODS

Surveys were obtained from 83 hearing parents of deaf children. A subset of 50 parents also underwent semi-structured interviews. Nine hypothetical outcomes, ranging from mainstream success to poor mainstream outcome were created to measure parents' overall preferences and preference for specific outcomes for their child who is deaf.

RESULTS

Among parents of eligible children (n = 50), approximately 2/3 considered implantation (n = 33). The other 1/3 did not consider implantation. Parents who were eligible but did not consider implantation placed significantly lower priority on mainstream success over bilingual success (P < 0.03), and on the child's ability to speak versus sign (P < 0.02). They also showed significantly higher concerns on the cost of services in general and on the availability of resources offered at the local school district (both P > 0.05). Parents of ineligible children (n = 30) rarely considered implantation, even if they showed similar aspirations in mainstream outcomes (P = 0.003). Semi-structured interview data supported these findings.

CONCLUSIONS

The decision to consider cochlear implantation is strongly influenced by the eligibility and by professionals' recommendations. However, for some parents, the decision goes beyond eligibility and is determined by parental preferences, goals, values, and beliefs. This highlights the importance of careful audiologic evaluation and professionals' awareness of and sensitivity to parental goals, values, and beliefs in evaluating the child's candidacy.

Cochlear implantation in a Mandarin Chinese-speaking child with auditory neuropathy

Auditory neuropathy (AN) is a hearing disorder characterized by the preservation of outer hair cell function despite the absence of auditory brainstem responses. The pathophysiology and etiology of this condition remain unknown. Recent studies have shown that some patients with AN benefit significantly from cochlear implantation. These patients have all been native speakers of Western languages. A 3-year-old Mandarin-speaking boy was referred to our center because of speech delay. After a series of audiological surveys, retro-cochlear lesion was impressed. During the 2-year period of rehabilitation, poor speech discrimination out of proportion to aided hearing thresholds led to the diagnosis of auditory neuropathy. Because of the limited benefit from amplification, he received a cochlear implant. Significant improvement of speech perception skills assessed by a Mandarin auditory perception test was noted shortly after implantation. The post-implantation performance in this Mandarin-speaking child was consistent with that of reports for implantees speaking Western languages. For Mandarin-speaking children with AN who fail to benefit from conventional treatment, cochlear implantation may be a good alternative choice.

Monosyllable speech perception of Japanese hearing aid users with prelingual hearing loss: implications for surgical indication of cochlear implant

OBJECTIVE

The monosyllable speech perception ability after years of educational intervention was compared between prelingually deafened pediatric hearing aid users and their cochlear implant counterparts.

DESIGN

An open-set monosyllabic speech perception test was conducted on all subjects. The test required subjects to indicate a corresponding Japanese character to that spoken by the examiner. Fifty-two subjects with prelingual hearing impairment (47 hearing aid users and 5 cochlear implant users) were examined.

RESULTS

Hearing aid users with average pure-tone thresholds less than 90 dB HL demonstrated generally better monosyllable perception than 70%, which was equivalent or better performance than that of the cochlear implant group. Widely dispersed speech perception was observed within the 90-99 dB HL hearing-aid user group with most subjects demonstrating less than 50% speech perception. In the cluster of >100 dB HL, few cases demonstrated more than 50% in speech perception. The perception ability of the vowel part of each mora within the cochlear implant group was 100% and corresponding to that of hearing aid users with moderate and severe hearing loss.

CONCLUSION

Hearing ability among cochlear implant users can be comparable with that of hearing aid users with average unaided pure-tone thresholds of 90 dB HL, after monosyllabic speech perception testing was performed.