Changes of voice and articulation in children with cochlear implants

Vocal control and speech production in cochlear implant listeners: A review within auditory-motor processing framework

A comprehensive literature review is conducted to summarize and discuss prior findings on how cochlear implants (CI) affect the users' abilities to produce and control vocal and articulatory movements within the auditory-motor integration framework of speech. Patterns of speech production pre- versus post-implantation, post-implantation adjustments, deviations from the typical ranges of speakers with normal hearing (NH), the effects of switching the CI on and off, as well as the impact of altered auditory feedback on vocal and articulatory speech control are discussed. Overall, findings indicate that CIs enhance the vocal and articulatory control aspects of speech production at both segmental and suprasegmental levels. While many CI users achieve speech quality comparable to NH individuals, some features still deviate in a group of CI users even years post-implantation. More specifically, contracted vowel space, increased vocal jitter and shimmer, longer phoneme and utterance durations, shorter voice onset time, decreased contrast in fricative production, limited prosodic patterns, and reduced intelligibility have been reported in subgroups of CI users compared to NH individuals. Significant individual variations among CI users have been observed in both the pace of speech production adjustments and long-term speech outcomes. Few controlled studies have explored how the implantation age and the duration of CI use influence speech features, leaving substantial gaps in our understanding about the effects of spectral resolution, auditory rehabilitation, and individual auditory-motor processing abilities on vocal and articulatory speech outcomes in CI users. Future studies under the auditory-motor integration framework are warranted to determine how suboptimal CI auditory feedback impacts auditory-motor processing and precise vocal and articulatory control in CI users.

Exposure to Canadian French Cued Speech Improves Consonant Articulation in Children With Cochlear Implants: Acoustic and Articulatory Data

PURPOSE

One of the strategies that can be used to support speech communication in deaf children is cued speech, a visual code in which manual gestures are used as additional phonological information to supplement the acoustic and labial speech information. Cued speech has been shown to improve speech perception and phonological skills. This exploratory study aims to assess whether and how cued speech reading proficiency may also have a beneficial effect on the acoustic and articulatory correlates of consonant production in children.

METHOD

Eight children with cochlear implants (from 5 to 11 years of age) and with different receptive proficiency in Canadian French Cued Speech (three children with low receptive proficiency vs. five children with high receptive proficiency) are compared to 10 children with typical hearing (from 4 to 11 years of age) on their production of stop and fricative consonants. Articulation was assessed with ultrasound measurements.

RESULTS

The preliminary results reveal that cued speech proficiency seems to sustain the development of speech production in children with cochlear implants and to improve their articulatory gestures, particularly for the place contrast in stops as well as fricatives.

CONCLUSION

This work highlights the importance of studying objective data and comparing acoustic and articulatory measurements to better characterize speech production in children.

Comparative Study on the Acoustic Analysis of Voice in Auditory Brainstem Implantees, Cochlear Implantees, and Normal Hearing Children

The aim of the study was to compare the acoustic characteristics of voice between Auditory Brainstem Implantees, Cochlear Implantees and normal hearing children. Voice parameters such as fundamental frequency, formant frequencies, perturbation measures, and harmonic to noise ratio were measured in a total of 30 children out of which 10 were Auditory Brainstem Implantees, 10 were Cochlear Implantees and 10 were normal hearing children. Parametric and nonparametric statistics were done to establish the nature of significance between the three groups. Overall deviancies were seen in the implanted group for all acoustic parameters. However abnormal deviations were seen in individuals with Auditory Brainstem Implants indicating the deficit in the feedback loop impacting the voice characteristics. The deviancy in feedback could attribute to the poor performance in ABI and CI. The CI performed comparatively better when compared to the ABI group indicating a slight feedback loop due to the type of Implant. However, there needs to be additional evidence supporting this and there is a need to carry out the same study using a larger sample size and a longitudinal design.

Beginner's Intelligibility Test (BIT): translation, cultural adaptation to Brazilian Portuguese and validation

OBJECTIVE

Translate and validate the Beginner's Intelligibility Test (BIT) speech intelligibility assessment instrument into Brazilian Portuguese.

METHOD

Study developed in two stages: 1st translation and cross-cultural adaptation of the Beginner's Intelligibility Test instrument into Brazilian Portuguese; 2nd application of the instrument. The second stage of the study involved 20 children using cochlear implants, aged between 4 and 11 years old, enrolled in the Cochlear Implant Program at Hospital das Clínicas de Ribeirão Preto, Faculty of Medicine of Ribeirão Preto, University of São Paulo. All data collection procedures were video, and audio recorded for analysis by judges. After orthographic transcription of each sentence repeated by the child, the judge was asked to score the participant's speech intelligibility and classify it according to criteria established in the literature.

RESULTS

The translation stage took place for the four lists and 40 sentences of the Beginner's Intelligibility Test (BIT) instrument into Brazilian Portuguese, the semantic, idiomatic, experimental and conceptual equivalences were considered, and it took place without any difficulties identified by the translators. The terms used in the Portuguese language were similar and those that presented differences among the translators did not bring significant divergences to its understanding. In the inter-evaluator analysis, there was reliability between the classification and the score obtained. Different judges evaluated the same children and a concordance was observed in classification and scoring.

CONCLUSIONS

Face validity of the BIT was confirmed through the understanding of each sentence of the four lists by the majority of children using cochlear implants participating in the pre-test phase. The content validity among experts was unanimous for the four lists of sentences. The Brazilian Portuguese adapted version maintained the semantic, idiomatic, conceptual, and cultural equivalence, according to the evaluation of the expert committee.

EVIDENCE LEVEL

02.

Effect of telepractice on pediatric cochlear implant users and provider vowel space: A preliminary report

Clear speaking styles are goal-oriented modifications in which talkers adapt acoustic-phonetic characteristics of speech to compensate for communication challenges. Do children with hearing loss and a clinical provider modify speech characteristics during telepractice to adjust for remote communication? The study examined the effect of telepractice (tele-) on vowel production in seven (mean age 4:11 years, SD 1:2 years) children with cochlear implants (CIs) and a provider. The first (F1) and second (F2) formant frequencies of /i/, /ɑ/, and /u/ vowels were measured in child and provider speech during one in-person and one tele-speech-language intervention, order counterbalanced. Child and provider vowel space areas (VSA) were calculated. The results demonstrated an increase in F2 formant frequency for /i/ vowel in child and provider speech and an increase in F1 formant frequency for /ɑ/ vowel in the provider speech during tele- compared to in-person intervention. An expansion of VSA was found in child and provider speech in tele- compared to in-person intervention. In children, the earlier age of CI activation was associated with larger VSA in both tele- and in-person intervention. The results suggest that the children and the provider adjust vowel articulation in response to remote communication during telepractice.

Speech production in Mandarin-speaking children with cochlear implants: a systematic review

OBJECTIVE

This study aimed to systematically review and critically appraise the literature describing the phonetic characteristics and accuracy of the consonants, vowels and tones produced by Mandarin-speaking children with cochlear implants (CIs).

DESIGN

The protocol in this review was designed in conformity with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. EBSCOhost, PubMed, Scopus, PsycINFO, ProQuest Central databases were searched for relevant articles which met the inclusion criteria.

STUDY SAMPLE

A total of 18 journal papers were included in this review.

RESULTS

The results revealed that Mandarin-speaking children with CIs perform consistently more poorly in their production of consonants, in particular on fricatives, have a smaller and less well-defined vowel space, and exhibit greater difficulties in tone realisation, notably T2 and T3, when compared to their normal-hearing (NH) peers. The results from acoustic and accuracy analyses are negatively correlated with CI implantation age, but largely positively correlated with hearing age.

CONCLUSIONS

Findings of this review highlight the factors that influence consonant, vowel and tone production in Mandarin-speaking children with CIs, thereby providing critical information for clinicians and researchers working with this population.

Basic Measures of Prosody in Spontaneous Speech of Children With Early and Late Cochlear Implantation

PURPOSE

Relative to normally hearing (NH) peers, the speech of children with cochlear implants (CIs) has been found to have deviations such as a high fundamental frequency, elevated jitter and shimmer, and inadequate intonation. However, two important dimensions of prosody (temporal and spectral) have not been systematically investigated. Given that, in general, the resolution in CI hearing is best for the temporal dimension and worst for the spectral dimension, we expected this hierarchy to be reflected in the amount of CI speech's deviation from NH speech. Deviations, however, were expected to diminish with increasing device experience.

METHOD

Of 9 Dutch early- and late-implanted (division at 2 years of age) children and 12 hearing age-matched NH controls, spontaneous speech was recorded at 18, 24, and 30 months after implantation (CI) or birth (NH). Six spectral and temporal outcome measures were compared between groups, sessions, and genders.

RESULTS

On most measures, interactions of Group and/or Gender with Session were significant. For CI recipients as compared with controls, performance on temporal measures was not in general more deviant than spectral measures, although differences were found for individual measures. The late-implanted group had a tendency to be closer to the NH group than the early-implanted group. Groups converged over time.

CONCLUSIONS

Results did not support the phonetic dimension hierarchy hypothesis, suggesting that the appropriateness of the production of basic prosodic measures does not depend on auditory resolution. Rather, it seems to depend on the amount of control necessary for speech production.

Vowel intelligibility in children with cochlear implants: An acoustic and articulatory study

In child cochlear implant (CI) users, early implantation generally results in highly intelligible speech. However, for some children developing a high level of speech intelligibility may be problematic. Studies of speech production in CI users have principally been based on perceptual judgment and acoustic measures. Articulatory measures, such as those collected using ultrasound provide the opportunity to more precisely evaluate what makes child CI users more intelligible. This study investigates speech production and intelligibility in children with CI using acoustic and articulatory measures. Ten children with unilateral or bilateral CIs and 13 children with normal hearing (NH) participated in the study. Participants repeated five English vowels (/a/, /e/, /i/, /o/, /u/) with and without auditory feedback. Ultrasound was used to capture tongue positions and acoustic signals were recorded simultaneously. The results showed that, despite quite similar acoustic results, the two speaker groups made different use of the tongue to implement vowel contrasts. Indeed, the tongue position was lower in the feedback OFF condition than the feedback ON condition for all participants, but the magnitude of this difference was larger for CI users than for their NH peers. This difference led to diminished intelligibility scores for CI users. This study shows the limitation of acoustic measurements alone and demonstrates how the use of articulatory measurements can explain intelligibility patterns. Moreover, our results show that when cochlear implantation occurs early in life and auditory feedback is available, CI users' intelligibility is comparable to that of their NH peers.

The Acoustic Characteristics of the Voice in Cochlear-Implanted Children: A Longitudinal Study

OBJECTIVE

The purpose of this study was to characterize changes in the voice and vowel articulation of prelingually deaf children after cochlear implantation.

METHODS

In this study, the patient group included 30 prelingually deaf children who underwent unilateral cochlear implantation at 4-6 years of age. The control group included normally hearing children of the same age. All deaf children had follow-ups before cochlear implantation and at 1, 3, 6, 12, and 24 months after implantation. The acoustic parameters, aerodynamic parameters, and vowel formants were measured in the patient group and compared with those of the control group.

RESULTS

All acoustic parameters, aerodynamic parameters, and vowel formants differed significantly between normally hearing children and prelingually deaf children. For prelingually deaf children, all of the above parameters gradually decreased after cochlear implantation. Furthermore, the acoustic parameters Jitter and Shimmer were significantly reduced as early as 6 months, whereas the fundamental frequency, the standard deviation of fundamental frequency, estimated subglottal pressure, aF1, iF2, and uF2 were significantly altered 12 months after implantation. However, statistically significant differences in these parameters were not observed between 12 and 24 months after cochlear implantation.

CONCLUSION

After cochlear implantation, prelingually deaf children established auditory feedback and improved voice control and vowel production.

Period for Normalization of Voice Acoustic Parameters in Indian Pediatric Cochlear Implantees

OBJECTIVE

The purpose of this study was to investigate the duration required by children with cochlear implants to approximate the norms of voice acoustic parameters.

STUDY DESIGN

The study design is retrospective.

METHODS

Thirty children with cochlear implants (chronological ages ranging between 4.1 and 6.7 years) were divided into three groups, based on the postimplantation duration. Ten normal-hearing children (chronological ages ranging between 4 and 7 years) were selected as the control group. All implanted children underwent an objective voice analysis using Dr. Speech software (Tiger DRS, Inc., Seattle, WA, USA) at 6 months and at 1 and 2 years of implant use. Voice analysis was done for the children in the control group and means were derived for all the parameters analyzed to obtain the normal values. Habitual fundamental frequency (HFF), jitter (frequency variation), and shimmer (amplitude variation) were the voice acoustic parameters analyzed for the vowels |a|, |i|, and |u|. The obtained values of these parameters were then compared with the norms.

RESULTS

HFF for the children with implant use for 6 months and 1 year did significantly differ from the control group. However, there was no significant difference (P > 0.5) observed in the children with implant use for 2 years, thus matching the norms. Jitter and shimmer showed a significant difference (P < 0.5) even at 2 years of implant use when compared with the control group.

CONCLUSIONS

The findings of the study divulge that children with cochlear implants approximate age-matched normal-hearing kids with respect to the voice acoustic parameter of HFF by 2 years of implant use. However, jitter and shimmer were not found to stabilize for the duration studied.

Multidimensional Voice Program Analysis in Profoundly Deaf Children: Quantifying Frequency and Amplitude Control

Characterization of the vocal profile of profoundly deaf children using an objective voice analysis was carried out in a university-based pediatric otolaryngology clinic. 21 persons ages 3.5 to 18 years were assessed. From each sustained phonation of the vowel /a/ the following acoustic variables were extracted: fundamental frequency (F0), jitter percentage, shimmer percentage, fundamental frequency variation (vF0), peak amplitude variation (vAM), and first, second, and third formant frequencies (F1, F2, F3). Mean F0 was 267.8 Hz and consistent with established normative data. Mean measurements of jitter (0.88%) and shimmer (3.5%) were also within normal limits. The notable feature of the acoustic analysis was a statistically significant elevation in vF0 (2.81%) and vAM (23.58%). With the exception of one subject, the F1, F2, and F3 formant frequencies were comparable to those for normal hearing children. Auditory deprivation results in poor long-term control of frequency and amplitude during sustained phonation. The inability to maintain a sustained phonation may represent the partial collapse of an internal model of voice and speech.

The effect of age of cochlear implantation on vocal characteristics in children

Background

Early cochlear implantation aids auditory feedback and supports better communication and self-monitoring of the voice. The objective of this study was to determine whether the age of cochlear implantation has an impact on vocal development in children implanted before age 4.

Method and procedures

The study consisted of 19 participants in total. All implant recipients (experimental group) were 3–5 years post-implantation, including four prelingual (0–2 years) and five perilingual (2–4 years) implant recipients. The control group consisted of 10 children whose hearing was within normal limits between the ages 3–6 years and 10 months, which was compared to the experimental group. Established paediatric norms were used for additional comparison. A questionnaire was used to gather information from each of the participant’s caregivers to determine whether other personal and contextual factors had an impact on voice production. An acoustic analysis was conducted for each participant using the Multi-Dimensional Voice Program of the Computerized Speech Lab.

Results

When the experimental group and the control group were compared, similar results were yielded for fundamental frequency and short-term perturbation (jitter and shimmer). More variability was noted in long-term frequency and amplitude measures, with significantly higher differences, and therefore further outside the norms, in the prelingual group when compared to the perilingual and control groups.

Conclusion

In this study, age of implantation did not impact vocal characteristics. Further research should include larger sample sizes, with participants that are age and gender matched.

Auditory feedback modulates development of kitten vocalizations

Effects of hearing loss on vocal behavior are species-specific. To study the impact of auditory feedback on feline vocal behavior, vocalizations of normal-hearing, hearing-impaired (white) and congenitally deaf (white) cats were analyzed at around weaning age. Eleven animals were placed in a soundproof booth for 30 min at different ages, from the first to the beginning of the fourth postnatal month, every 2 weeks of life. In total, 13,874 vocalizations were analyzed using an automated procedure. Firstly, vocalizations were detected and segmented, with voiced and unvoiced vocalizations being differentiated. The voiced isolation calls (‘meow’) were further analyzed. These vocalizations showed developmental changes affecting several parameters in hearing controls, whereas the developmental sequence was delayed in congenitally deaf cats. In hearing-impaired and deaf animals, we observed differences both in vocal behavior (loudness and duration) and in the calls’ acoustic structure (fundamental frequency and higher harmonics). The fundamental frequency decreased with age in all groups, most likely due to maturation of the vocal apparatus. In deaf cats, however, other aspects of the acoustic structure of the vocalizations did not fully mature. The harmonic ratio (i.e., frequency of first harmonic divided by fundamental frequency) was higher and more variable in deaf cats than in the other study groups. Auditory feedback thus affects the acoustic structure of vocalizations and their ontogenetic development. The study suggests that both the vocal apparatus and its neuronal motor control are subject to maturational processes, whereas the latter is additionally dependent on auditory feedback in cats.

Resonance frequencies behavior in pathologic cries of newborns

OBJECTIVE

A new approach to the automatic quantification of the acoustic parameters of the cries of healthy newborns and newborns with pathologies is presented. The purpose of the present study was to examine the relationship between acoustic parameters and pathologies of interest to characterize healthy and pathologic cries of newborns.

METHODS

Using MATLAB, this study included automatic estimation of F0, RF1, RF2, percentage and tuning duration, transition duration, RF2 slope, and RF1:RF2 ratio. The database used includes full- and pre-term newborns, healthy, and pathologic cries. It contains 3000 cry samples of 1-second duration from 65 newborn babies aged from 1 day to 1 month old.

RESULTS

Statistical analysis results reveal that the distributions of these acoustic cry parameters depend on the pathology of newborn. In this work, we successfully identify the quantitative relationship between the acoustic cry characteristics we examined and the diseases we studied.

CONCLUSIONS

Our deduction is that quantification of the variability of these parameters is useful for differentiating the cries of a healthy newborn from those of a newborn with a pathology, and that these data can be used for the early diagnosis of newborn diseases.

Diferenças entre parâmetros vocais em crianças usuárias de implante coclear e em crianças usuárias de aparelho de amplificação sonora individual

OBJETIVO: realizar um estudo comparativo entre os parâmetros vocais freqüência fundamental, frequência do primeiro formante e frequência do segundo formante da voz de crianças usuárias de implante coclear, da voz de crianças usuárias de aparelho de amplificação sonora individual e da voz de crianças ouvintes normais. MÉTODO: a amostra foi composta por 18 crianças (12 meninas e 6 meninos), numa faixa etária entre 5 e 7 anos (média de idade 6,3 anos). A gravação das amostras foi realizada no laboratório de voz da Clínica de Fonoaudiologia da Universidade Federal do Rio Grande do Norte, em Natal. A análise acústica foi realizada utilizando-se o programa PRAAT. Os parâmetros analisados foram frequência fundamental e frequência do segundo formante da emissão da vocal [a] sustentada e frequência dos primeiro e segundo formante da vogal [a] das silabas [ka] e [pa]. RESULTADOS: com exceção do primeiro formante da vogal [a] da silaba [pa] que apresentou diferença estatisticamente significante entre os valores dos grupos de usuários de implante coclear e do grupo de ouvintes normais, os demais parâmetros apresentaram diferença estatisticamente significante entre os três grupos. CONCLUSÃO: as crianças usuárias de implante coclear apresentaram valores acústicos próximos aos apresentados pelas crianças ouvintes normais, sendo esses valores mais adequados do que os apresentados pelas crianças usuárias de aparelho de amplificação sonora indivdual.

Systematic analysis of the benefits of cochlear implants on voice production

PURPOSE

To perform a systematic analysis of the research regarding vocal characteristics of hearing impaired children or adults with cochlear implants.

RESEARCH STRATEGY

A literature search was conducted in the databases Web of Science, Bireme, and Universidade de São Paulo's and CAPES' thesis and dissertations databases using the keywords voice, voice quality, and cochlear implantation, and their respective correspondents in Brazilian Portuguese.

SELECTION CRITERIA

The selection criteria included: title consistent with the purpose of this review; participants necessarily being children or adults with severe to profound pre-lingual or post-lingual hearing loss using cochlear implants; and data regarding participants' performance on perception and/or acoustic analysis of the voice.

RESULTS

Twenty seven papers were classified according to the levels of evidence and quality indicators recommended by the American Speech-Language-Hearing Association (ASHA). The designs of the studies were considered of low and medium levels of evidence. Six papers were classified as IIb, 20 as III, and one as IV.

CONCLUSION

The voice of hearing impaired children and adults with cochlear implants has been little studied. There is not an effective number of studies with high evidence levels which precisely show the effects of the cochlear implantation on the quality of voice of these individuals.

Cochlear implanted children present vocal parameters within normal standards

OBJECTIVE

to compare acoustic and perceptual parameters regarding the voice of cochlear implanted children, with normal hearing children.

METHOD

this is a cross-sectional, quantitative and qualitative study.

METHODS

Thirty six cochlear implanted children aged between 3 y and 3 m to 5 y and 9 m and 25 children with normal hearing, aged between 3 y and 11 m and 6 y and 6 m, participated in this study. The recordings and the acoustics analysis of the sustained vowel/a/and spontaneous speech were performed using the PRAAT program. The parameters analyzed for the sustained vowel were the mean of the fundamental frequency, jitter, shimmer and harmonic-to-noise ratio (HNR). For the spontaneous speech, the minimum and maximum frequencies and the number of semitones were extracted. The perceptual analysis of the speech material was analyzed using visual-analogical scales of 100 points, composing the aspects related to the overall severity of the vocal deviation, roughness, breathiness, strain, pitch, loudness and resonance deviation, and instability. This last parameter was only analyzed for the sustained vowel.

RESULTS

The results demonstrated that the majority of the vocal parameters analyzed in the samples of the implanted children disclosed values similar to those obtained by the group of children with normal hearing.

CONCLUSION

implanted children who participate in a (re) habilitation and follow-up program, can present vocal characteristics similar to those vocal characteristics of children with normal hearing.

Preoperative voice parameters affect the postoperative speech intelligibility in patients with cochlear implantation

OBJECTIVES

Verbal communication depends on a good function of voice and speech organs. Some of the voice characteristics of deaf people differ considerably from those of speakers with normal hearing. After cochlear implantation (CI), auditory control of voice production is possible and the quality of the voice is improved. CI improves quality of voice, speech and hearing with deafness. The aim of our study was to investigate the relationship between acoustic analysis before CI and the speech intelligibility before and after CI.

METHODS

Twelve prelingually deafened children implanted unilaterally at the age of 3.4-9 years were included in the study. For all of the children an acoustic analysis of the Slovene vowel 'a' was performed before CI. The fundamental frequency (F0), jitter, shimmer and noise-to-harmonic ratio (NHR) were studied before the implantation. For all of the children the speech intelligibility was performed before and 12 months after CI. Preoperative hearing was divided on existing residual hearing. The results of the acoustic analyses and speech intelligibility before and after CI were compared for preoperative hearing. The results of the speech intelligibility were compared for the age of operation and preoperative acoustic analysis (F0, jitter, shimmer, NHR).

RESULTS

Preoperative hearing had no influence on preoperative voice analysis. The children with residual hearing had a high grade of speech intelligibility before and after CI. The preoperative shimmer had positive correlation with postoperative 12 month speech intelligibility (r=0.618, P=0.032). The preoperative jitter had positive correlation with postoperative 12 month speech intelligibility, but was not statistically significant (r=0.479, P=0.116).

CONCLUSION

Shimmer on preoperative voice analyses had influence on speech intelligibility after CI.

Speech intelligibility, speaking rate, and vowel formant characteristics in Mandarin-speaking children with cochlear implant

The effects of the use of cochlear implant (CI) on speech intelligibility, speaking rate, and vowel formant characteristics and the relationships between speech intelligibility, speaking rate, and vowel formant characteristics for children are clinically important. The purposes of this study were to report on the comparisons for speaking rate and vowel space area, and their relationship with speech intelligibility, between 24 Mandarin-speaking children with CI and 24 age-sex-education level matched normal hearing (NH) controls. Participants were audio recorded as they read a designed Mandarin intelligibility test, repeated prolongation of each of the three point vowels /i/, /a/, and /u/ five times, and repeated each of three sentences carrying one point vowel five times. Compared to the NH group, the CI group exhibited: (1) mild-to-moderate speech intelligibility impairment; (2) significantly reduced speaking rate mainly due to significantly longer inter-word pauses and larger pause proportion; and (3) significantly less vowel reduction in the horizontal dimension in sustained vowel phonation. The limitations of speech intelligibility development in children after cochlear implantation were related to atypical patterns and to a smaller degree in vowel reduction and slower speaking rate resulting from less efficient articulatory movement transition.

Characteristics of nasal resonance and perceptual rating in prelingual hearing impaired adults

Objectives

Resonance problems in hearing impaired (HI) individuals have been described as aspects of nasality. However, there are limitations in being able to explain the range of resonance problems. Therefore, this study suggests a perceptual rating that will effectively explain the characteristics of resonance problems in HI individuals.

Methods

Nasalance scores were obtained from 32 subjects in each of HI and normal hearing (NH) groups using a nasometer. The subjects were categorized into groups based on normal and abnormal nasalance ranges. The abnormal nasalance range group was further divided into hyper-, hypo-, and mixed-nasal groups. Nasalance scores were based the individuals performance in a series of passage and syllable tasks. The perceptual rating was evaluated using a newly introduced tool, 'vertical focus of resonance' (VFR), which focuses on the resonance energy in the frontal, throat, pharyngeal and nasal locations.

Results

The NH group demonstrated a significantly lower nasalance score in the oral coupling and passage tasks than the HI group. Based on the results of nasalance correlation analysis, the HI group showed highly significant correlations between syllable and passage tasks, as contrasted with the NH group. There were significant differences in VFR between the nasalance types in both the NH and the HI groups.

Conclusion

The HI hyper-nasal group showed tendencies of velopharyngeal opening, as opposed to the HI hypo-nasal group which showed tendencies of velopharyngeal closure. The HI mixed-nasal group showed inappropriate coordination of velopharyngeal function. In the HI group, the results of VFR showed that the air flow and the resonance energy were not released from the cavity of resonance. The suggested VFR tool explains the focusing characteristics of resonance energy within a continuation of speech sound regardless of the phonetic environment. Therefore, VFR may be a useful tool in explaining the deviant resonance patterns of HI individuals.

Classification of voice disorder in children with cochlear implantation and hearing aid using multiple classifier fusion

Background

Speech production and speech phonetic features gradually improve in children by obtaining audio feedback after cochlear implantation or using hearing aids. The aim of this study was to develop and evaluate automated classification of voice disorder in children with cochlear implantation and hearing aids.

Methods

We considered 4 disorder categories in children's voice using the following definitions:

Level_1: Children who produce spontaneous phonation and use words spontaneously and imitatively.

Level_2: Children, who produce spontaneous phonation, use words spontaneously and make short sentences imitatively.

Level_3: Children, who produce spontaneous phonations, use words and arbitrary sentences spontaneously.

Level_4: Normal children without any hearing loss background. Thirty Persian children participated in the study, including six children in each level from one to three and 12 children in level four. Voice samples of five isolated Persian words "mashin", "mar", "moosh", "gav" and "mouz" were analyzed. Four levels of the voice quality were considered, the higher the level the less significant the speech disorder. "Frame-based" and "word-based" features were extracted from voice signals. The frame-based features include intensity, fundamental frequency, formants, nasality and approximate entropy and word-based features include phase space features and wavelet coefficients. For frame-based features, hidden Markov models were used as classifiers and for word-based features, neural network was used.

Results

After Classifiers fusion with three methods: Majority Voting Rule, Linear Combination and Stacked fusion, the best classification rates were obtained using frame-based and word-based features with MVR rule (level 1:100%, level 2: 93.75%, level 3: 100%, level 4: 94%).

Conclusions

Result of this study may help speech pathologists follow up voice disorder recovery in children with cochlear implantation or hearing aid who are in the same age range.

The influence of the auditory prosthesis type on deaf children's voice quality

OBJECTIVE

In the last years, technology has made it possible for deaf people, and especially for deaf children, to enter the world of sound and, as a consequence, to facilitate communicative competence in oral language, which used to be an insurmountable obstacle. With this article we are trying to carry out a revision of the descriptions that have traditionally featured deaf children's voice.

METHODS

We analyse the voice quality obtained out of a research with 62 children (35 girls and 27 boys) with profound deafness of several degrees, aged on average 7 years 4 months, and users of different types of auditory prostheses (analogue/digital hearing aids or cochlear implants) experimental group--Voice quality was evaluated from the production of a sustained vowel /a:/ for four-five seconds, considering F(0), jitter, shimmer and NHR values.

RESULTS

The results are compared with the ones obtained from a control group of hearing children (n=54). The Experimental Group shows altered voice quality parameters. Particularly in F(0) (294.079 Hz) and shimmer (0.568 dB), there are statistically significant values in comparison with the control group (p<0.001). With regards to jitter (1.474%), differences were smaller. Nevertheless, the results show how the profiles reached by deaf children are nowadays more similar to those reached by the hearing control group. However, the degree of hearing impairment and the type of prosthesis used can determine the parameters of deaf children's voice quality to a great extent. Thus, the digital hearing aid users are the ones who present better voice quality values: F(0) (265.50 z); jitter (1.009%) and shimmer (0.486 dB); whereas implant users: F(0) (287.93 z); jitter (1.344%) and shimmer (0.526 dB), and particularly analogue hearing aid users: F(0) (323.80 z); jitter (1.999%) and shimmer (0.687 dB), did show significant differences in comparison with the control group of hearing children.

CONCLUSIONS

In the study of voice quality in children with profound hearing loss, it is very important to have information both about the degree of hearing loss and the kind of prosthesis used. Implant users show more altered voice quality than digital hearing aid users. However, the hearing loss they compensate is much more important than the hearing loss compensated by the hearing aids. Therefore, we consider that both prostheses help children with hearing loss to have a more normalized voice quality than what scientific literature has traditionally stated. Finally, we question the validity of using some acoustic parameters as indicators of voice quality in deaf children having no laryngeal problems.

Acoustic analysis of voice in cochlear implant recipients with post-meningitic hearing loss

The objective of this study was to evaluate the critical time period between the onset of sensorineural hearing loss and cochlear implantation with respect to normal voice production in children with post-meningitic hearing loss. Acoustic measures of voice production were obtained from ten paediatric cochlear implant recipients with post-meningitic hearing loss. Acoustic measures were obtained utilising the Multi-Dimensional Voice Program and Computerized Speech Laboratory (Kay Elemetrics Corp.). Measures were based on sustained phonation of the vowel /a/. Acoustic parameters included fundamental frequency, short- and long-term frequency perturbation, and short- and long-term amplitude perturbation. Measures of fundamental frequency and short-term frequency and amplitude perturbation were comparable to values of children with normal hearing. Long-term control of frequency was within normal limits for subjects with a period of auditory deprivation of less than four months. Measures of long-term amplitude perturbation were normal for all patients except those with cochlear ossification. Early restoration of auditory feedback with cochlear implantation, the absence of cochlear ossification, residual aided hearing following meningitis, and auditory-verbal therapy were identified as factors in preserving the long-term control of frequency and amplitude in the setting of post-meningitic hearing loss.

The relationship between pitch discrimination and vocal production: comparison of vocal and instrumental musicians

Auditory pitch discrimination and vocal pitch accuracy are fundamental abilities and essential skills of a professional singer; yet, the relationship between these abilities, particularly in trained vocal musicians, has not been the subject of much research. Difference limens for frequency (DLFs) and pitch production accuracy (PPA) were examined among 20 vocalists, 21 instrumentalists, and 21 nonmusicians. All were right-handed young adult females with normal hearing. Stimuli were harmonic tone complexes simulating piano tones and represented the mid-frequency of the untrained female vocal range, F0=261.63-392 Hz (C4-G4). DLFs were obtained by an adaptive psychophysical paradigm. Vocal pitch recordings were analyzed to determine PPA. Musicians demonstrated superior pitch discrimination and production accuracy compared to nonmusicians. These abilities did not distinguish instrumentalists and vocalists. DLF and PPA were significantly correlated with each other only for musicians with instrumental training; however, PPA was most consistent with minimal variance for vocalists. It would appear that a relationship between DLF and PPA develops with musical training, and these abilities can be differentially influenced by the type of specialty training.

Principais características da produção vocal do deficiente auditivo

OBJETIVO: descrever as principais características da produção vocal do deficiente auditivo, analisando quais os parâmetros da qualidade vocal são alterados pela deficiência da audição. MÉTODOS: foi realizado um levantamento bibliográfico em Bibliotecas de Universidades e pesquisa em periódicos indexados na Base de dados Lilacs e Medline, dando ênfase aos estudos referentes ao tema desde 1971 até os estudos mais recentes. RESULTADOS: os achados foram divididos em seis parâmetros: Características da Fala; Ressonância; Respiração; Parâmetros Acústicos; Aspectos Fonéticos e Tratamento Fonoaudiológico. CONCLUSÃO: com a revisão da literatura, foi possível identificar as principais características da produção vocal do deficiente auditivo. A discriminação e a realimentação auditivas são essenciais na produção da voz, e, no caso dos deficientes auditivos, como não desenvolvem o feedback auditivo, não conseguem ter controle sobre sua voz: (ressonância, intensidade, freqüência, articulação e respiração). A relevância da contribuição da Fonoaudiologia fica clara graças à garantia de melhora nas condições de comunicação desses indivíduos.

Longitudinal formant analysis after cochlear implantation in school-aged children

INTRODUCTION

The purpose of this investigation was to describe the correlation between vocal and hearing development by longitudinal analysis of sound spectrograms, as a basic system for evaluating progress in vocal development.

SUBJECTS AND METHODS

Two school-aged children with prelingual deafness were evaluated diachronically to assess speech perception and speech intelligibility after cochlear implantation. One child had non-syndromic hearing impairment without any known neurological deficit except for hearing loss, while the other had hearing impairment accompanied by mild mental retardation and attention deficit disorder. Their voices were recorded for monthly follow-up after cochlear implantation; these were used for formant analysis and compared with their mother's voice, and alteration of the formant data was also compared with monosyllable speech perception.

RESULTS

Formant analysis demonstrated high concordance was observed between monosyllable speech perception and speech intelligibility. F1-F2 forms of the patients more closely resembled those of their mothers after 1 year's follow-up. The time point at which speech development altered was very similar in both cases although the final outcomes were different.

CONCLUSION

Fair improvement of articulation after cochlear implant was demonstrated by the F1-F2 gram analysis. This procedure can be used for data sharing and cooperation between medical and educational specialists.

Acoustic and perceptual appraisal of speech production in pediatric cochlear implant users

OBJECTIVE

The purpose of the present study was to examine the relationship between objectively measurable acoustic changes in speech production and subjective speech production accuracy and perceived intelligibility immediately following a disruption in auditory feedback normally provided to subjects from a cochlear implant.

METHODS

Six children with profound sensorineural hearing loss participated in the study. Their task was to produce speech samples in two conditions: (1) with auditory feedback from their cochlear implants, and (2) without auditory feedback from their cochlear implants. Samples were subjected to both objective and subjective analyses. Objectively, measures were made of duration, fundamental frequency, and the first and second formants of the vowels. Subjectively, two groups of listeners, one familiar with the speech of children with hearing loss and the other unfamiliar, transcribed the productions and provided ratings of intelligibility.

RESULTS

All the children in this study exhibited significant differences from the cochlear implant-on to the cochlear implant-off condition, although these changes were not always in the predicted direction, nor were they always perceptually salient.

CONCLUSIONS

Consistent with previous studies, children in this investigation demonstrated variable acoustic voice and speech changes following deactivation of their cochlear implant device. Few of these acoustic changes affected speech intelligibility. The results of this study overall suggest that during the initial years following implantation children who are deaf rely to some extent on the auditory feedback provided by a cochlear implant to control and modify F0, duration, and vowel formant production.

Comparison of the overall intelligibility, articulation, resonance, and voice characteristics between children using cochlear implants and those using bilateral hearing aids: a pilot study

The purpose of this study was to determine and to compare the overall intelligibility, articulation, resonance, and voice characteristics in children using cochlear implants (CI) and children using conventional hearing aids (HA). Nine prelingually deaf children using CI and six children with a prelingual severe hearing loss using HA, were selected to participate. Objective (DSI, nasalance scores) as well as subjective assessment techniques (perceptual evaluations) were used. Both the CI and HA children demonstrated normal vocal quality and resonance but showed the presence of articulation disorders. In the CI children, intelligibility was significantly better compared to the HA children. Significantly more phonetic and phonological disorders were present in the HA children. The results of this study show a poorer intelligibility of the HA children in comparison with the CI children which is probably due to the occurrence of significantly more phonetic and phonological disorders. Future detailed analysis in a larger sample of CI and HA children may help further clarify the issue of speech and voice characteristics and may demonstrate an important prognostic value.

The influence of cochlear implantation on some voice parameters

OBJECTIVE

Some of the voice characteristics of deaf people differ considerably from those of speakers with normal hearing. After a cochlear implantation, auditory control of voice production is possible and the quality of the voice is improved. The aim of this study was to investigate the changes in some of the voice parameters in deaf children after cochlear implantation.

METHODS

Thirty-one prelingually deafened children implanted unilaterally at the age of 2.5-13 years were included in the study. For all of the children an acoustic analysis (Multi-Dimensional Voice Program, Kay Elemetrics Corp., USA) of the Slovene vowel 'a' was performed before cochlear implantation and 6, 12 and 24 months after the implantation. The fundamental frequency (F0), jitter, shimmer and noise-to-harmonic ratio (NHR) were compared before and after the implantation. The results of the acoustic analyses were compared for the children who were implanted before or at the age of 4 years and the children who were implanted after the age of 4 years.

RESULTS

After the cochlear implantation the fundamental frequency did not change significantly. However, an improvement was noticed in the measurements of jitter (p=0.006) and shimmer (p=0.021) as early as 6 months after the implantation. The noise-to-harmonic ratio improved (p=0.013) 24 months after the implantation. The children implanted before or at the age of 4 years showed a significant improvement in jitter (p=0.003) and shimmer (p=0.004) as early as 6 months and in noise-to-harmonic ratio (p=0.021) 12 months after the implantation. In the children implanted after the age of 4 years the only significant change was detected in F0 (p=0.045), 12 months after the implantation, and in Shimmer (p=0.017), 24 months after the implantation.

CONCLUSION

The results of the present study have confirmed that cochlear implantation enables auditory moment-to-moment control of pitch and loudness. The determination of jitter and shimmer in the vowel 'a' sample proved to be a good and early indicator of improved phonation control, even in young children. The deaf children who were implanted before the age of 4 years improved their voice control more quickly and to a greater extent than the children implanted after the age of 4 years.

Acoustic Analysis of the Voice in Pediatric Cochlear Implant Recipients: A Longitudinal Study

OBJECTIVE

To characterize inherent acoustic abnormalities of the deaf pediatric voice and the effect of artificially restoring auditory feedback with cochlear implantation.

DESIGN

Inception cohort.

SETTING

Academic referral center.

PATIENTS

Twenty-one children with severe to profound hearing loss (15 prelingually deaf, 6 postlingually deaf) accepted into the cochlear implant program were followed for up to 6 months. Patients unable to perform the vocal exercises were excluded.

INTERVENTIONS

Objective voice analysis was performed using the Computerized Speech Laboratory (Kay Elemetrics) prior to cochlear implantation, at the time of implant activation and at 2 and 6 months postactivation. Assessments were based on sustained phonations and dynamic ranges.

MAIN OUTCOME MEASURE

Fundamental frequency, long-term control of fundamental frequency (vF0) and long-term control of amplitude (vAM) were derived from sustained phonations. The dynamic frequency range was derived from scale exercises. Formant frequencies (F1, F2, F3) were determined using linear predictive coding.

RESULTS

Fundamental frequency was not altered by implant activation or experience (P = 0.342). With profoundly deaf subject, the most prevalent acoustic abnormality was a poor long-term control of frequency (vF0, 2.81%) and long-term control of amplitude (vAm, 23.58%). Implant activation and experience had no effect on the long-term control of frequency (P = 0.106) but normalized the long-term control of amplitude (P = 0.007). The mean frequency range increased from 311.9 Hz preimplantation to 483.5 Hz postimplantation (P = 0.08). The F1/F2 ratio remained stable (P = 0.476).

CONCLUSION

In children, severe to profound deafness results in poor long-term control of frequency and amplitude. Cochlear implantation restores control of amplitude only and implies the need for additional rehabilitative strategies for restoration of control of frequency.

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.