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

On the interplay between speech perception and production: insights from research and theories

The study of spoken communication has long been entrenched in a debate surrounding the interdependence of speech production and perception. This mini review summarizes findings from prior studies to elucidate the reciprocal relationships between speech production and perception. We also discuss key theoretical perspectives relevant to speech perception-production loop, including hyper-articulation and hypo-articulation (H&H) theory, speech motor theory, direct realism theory, articulatory phonology, the Directions into Velocities of Articulators (DIVA) and Gradient Order DIVA (GODIVA) models, and predictive coding. Building on prior findings, we propose a revised auditory-motor integration model of speech and provide insights for future research in speech perception and production, focusing on the effects of impaired peripheral auditory systems.

A Comparative Study of Voice Characteristics in Children With Cochlear Implants and Typically Hearing Children: Insights From an Indian Context

Purpose The aim of the study was to evaluate speech outcomes in children with cochlear implants compared to normally hearing children in terms of fundamental frequency, shimmer, and jitter. The study also aims to assess the intelligibility of speech in children with cochlear implants using a speech intelligibility rating scale. Methods This was a hospital-based comparative study conducted at JIPMER, a major tertiary referral center. A total of 25 prelingually deaf children with profound deafness, who underwent cochlear implantation at the institute, were recruited from the outpatient department of the Department of Otorhinolaryngology. Twenty-five children under seven years of age who underwent cochlear implantation and received a minimum of 36 speech therapy sessions were included in the study. Subjects with incomplete electrode array insertion and any neurological maldevelopment were excluded. Age- and gender-matched controls comprising 25 individuals were selected from the Ophthalmology Outpatient Department at JIPMER. Study procedure The study commenced in January 2019. Test subjects were asked to visit the Audiology and Speech and Language Pathology Department at JIPMER. Voice recordings were conducted in a soundproof room using a microphone, with the mouthpiece held at a distance of 10-15 cm from the patient. The patient was instructed to say "a" three times. Their voice was recorded and analyzed using Praat software (Version 6.1.15, developed by Paul Boersma and David Weenink, Phonetic Sciences, University of Amsterdam). Data were analyzed using IBM SPSS Statistics for Windows, Version 19 (Released 2010; IBM Corp., Armonk, New York) (Department of Biostatistics, Vanderbilt University, Nashville, Tennessee, USA), and the results were derived. Results The mean fundamental frequency for Group 1 (CI) was 266.03 ± 57.46 Hz, compared to 312.97 ± 22.15 Hz for Group 2 (NH). There was a statistically significant difference between the values of both groups, indicating that cochlear implantation positively impacted the fundamental frequency of speech. The study revealed a significant change in the fundamental frequency when children were implanted at an early age and received effective speech therapy post-implantation. This change was assessed after one year post-implant. Perturbation measures such as shimmer and jitter were lower in the cochlear implant group but were not statistically significant. Conclusion Children with congenital bilateral severe to profound sensorineural hearing loss tend to have higher values of the fundamental frequency of speech. However, when implanted at an early age, they showed a significant difference in the fundamental frequency of speech (p < 0.001). Speech perturbation was lower in the post-cochlear implant group, with a statistically significant difference in the values of shimmer alone. The study concludes that children with cochlear implants can achieve normal voice parameters with early intervention and training. However, the variability range is much higher than in typically hearing individuals.

Effects of Prosody Rehabilitation on Acoustic Analysis of Prosodic Features in Hearing-Impaired Children: A Randomized Controlled Trial

BACKGROUND

The role of prosody in language acquisition and effective communication is documented in research. Nevertheless, rehabilitation of prosodic skills in children with hearing impairment using hearing aids or cochlear implants is relatively neglected compared to other speech and language areas.

OBJECTIVE

To detect the effect of prosodic rehabilitation using the adapted translated version of the "Prosody Treatment Program" on expression of prosodic features in Egyptian Arabic-speaking hearing-impaired school-age children fitted with hearing aids or cochlear implant devices in comparison to conventional auditory and language rehabilitation.

METHODS

This study was conducted on 34 children with sensorineural hearing loss in a randomized controlled trial design. Children were randomly divided into 2 groups, group A (cases) and group B (control), by block randomization. Both groups were initially evaluated for their prosodic skills using objective measures. Group A received rehabilitation for prosody using the Prosody Treatment Program for 1 h, once per week for 3 months, while group B received conventional auditory and language training and served as their control. Both groups were re-evaluated using the same protocol after 3 months of therapy.

RESULTS

A statistically significant improvement of most of the assessed prosodic parameters in group A was shown when comparing the pretherapy and posttherapy scores, as well as comparing between both studied groups after therapy.

CONCLUSIONS

Prosody is amenable to motor learning. The Prosody Treatment Program seems to be an effective rehabilitation tool in improving some prosodic skills of hearing-impaired children. Prosodic rehabilitation showed superiority to conventional auditory and language training in improving the expression of some prosodic features and pragmatic language skills.

Fundamental Frequency and Jitter Percent in MDVP and PRAAT

PURPOSE

This study initially investigated the relationship between Fundamental Frequency and Jitter Percent across and within MDVP and PRAAT. Subsequently, it explored if the measured acoustic signal's Length or the analysis temporal segment selection impacts potential correlation across the tools' measures.

METHODS

We collected forty-two Maximum Phonation Time acoustic signals from 10 participants with Healthy Voices in a standardized setting. We excluded from enrollment any potential participants having a history of voice disorders or showing an abnormality in a pre-study assessment.

RESULTS

There is no correlation between Jitter percent's values and Fundamental Frequency within either Tool in our healthy voice samples. The Length of the acoustic signal and temporal analysis selection impact the correlation between Jitter Percent measurements across the two tools; The correlation between Fundamental Frequency measurements across the devices was not affected. Means of Fundamental Frequency did not differ across the two devices but show a persistent pattern of greater values in MDVP. Jitter Percent measurements were significantly higher in MDVP CONCLUSIONS: There is a potential for clinicians using PRAAT assessments in the clinic to make inferences from research using MDVP as an analysis tool. Further work is needed in patients with Voice disorders to explore that possibility.

Acoustically Induced Vocal Training for Individuals With Impaired Hearing

OBJECTIVES/HYPOTHESIS

Articulation, phonation, and resonance disorders in the speech of hearing-impaired-speakers reduces intelligibility. The study focusses on (1) whether nonacoustic feedback may facilitate the adjustment of the vocal tract, leading to increased vocal tract resonance, and (2) whether training with the feedback would be helpful for the subsequent formation of vowels.

STUDY DESIGN

Prospective.

METHODS

Seven profoundly hearing-impaired participants used acoustic sound waves in the frequency range of the first two vocal tract resonances applied in front of the open mouth at intensities above 1 Pa. They were asked to amplify the sound via adjusting the vocal tract. The sound waves corresponded to the first and second resonance frequencies of the vowels [u], [o], and [a]. The self-assessment of the participants and a software-based/auditory analysis was reported.

RESULTS

The participants were able to enhance the acoustic signal by adjusting the vocal tract shape. The self-perception of the participants, the auditory voice analysis, and the acoustic analysis of vowels were consistent with each other. While the maximum sound pressure levels were constant, the mean sound pressure levels increased. Breathiness and hoarseness declined during the exercises. Resonance/harmonic-to-noise ratio increased, especially for the vowels [u], [o], [a]. Furthermore, the positively connoted feedback from the participants indicated easier sound production.

CONCLUSION

Nonauditory feedback, based on acoustic waves, could be suitable for improving the formation of vowels. The findings are in accordance with a reduction of acoustic losses within the vocal tract.

Mechanisms of voice control related to prosody in autism spectrum disorder and first-degree relatives

Differences in prosody (e.g., intonation, rhythm) are among the most obvious language-related impairments in autism spectrum disorder (ASD), and significantly impact communication. Subtle prosodic differences have also been identified in a subset of clinically unaffected first-degree relatives of individuals with ASD, and may reflect genetic liability to ASD. This study investigated the neural basis of prosodic differences in ASD and first-degree relatives through analysis of feedforward and feedback control involved in the planning, production, self-monitoring, and self-correction of speech by using a pitch-perturbed auditory feedback paradigm during sustained vowel and speech production. Results revealed larger vocal response magnitudes to pitch-perturbed auditory feedback across tasks in ASD and ASD parent groups, with differences in sustained vowel production driven by parents who displayed subclinical personality and language features associated with ASD (i.e., broad autism phenotype). Both ASD and ASD parent groups exhibited increased response onset latencies during sustained vowel production, while the ASD parent group exhibited decreased response onset latencies during speech production. Vocal response magnitudes across tasks were associated with prosodic atypicalities in both individuals with ASD and their parents. Exploratory event-related potential (ERP) analyses in a subgroup of participants during the sustained vowel task revealed reduced P1 ERP amplitudes in the ASD group, with similar trends observed in parents. Overall, results suggest underdeveloped feedforward systems and neural attenuation in detecting audio-vocal feedback may contribute to ASD-related prosodic atypicalities. Importantly, results implicate atypical audio-vocal integration as a marker of genetic risk to ASD, evident in ASD and among clinically unaffected relatives. Autism Res 2019, 12: 1192-1210. © 2019 The Authors. Autism Research published by International Society for Autism Research published by Wiley Periodicals, Inc. LAY SUMMARY: Previous research has identified atypicalities in prosody (e.g., intonation) in individuals with ASD and a subset of their first-degree relatives. In order to better understand the mechanisms underlying prosodic differences in ASD, this study examined how individuals with ASD and their parents responded to unexpected differences in what they heard themselves say to modify control of their voice (i.e., audio-vocal integration). Results suggest that disruptions to audio-vocal integration in individuals with ASD contribute to ASD-related prosodic atypicalities, and the more subtle differences observed in parents could reflect underlying genetic liability to ASD.

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.

Hearing Aid Use and Auditory Verbal Therapy Improve Voice Quality of Deaf Children

BACKGROUND

Adequate phonation is self-regulated by auditory feedback. Children with bilateral profound hearing loss (PHL) lack this feedback resulting in abnormal voice. Adequate hearing aid use and auditory-verbal therapy (AVT) may improve voice quality in deaf children.

OBJECTIVE

To study whether hearing aid use and AVT approach improve acoustic parameters of voice of children with bilateral PHL.

MATERIALS AND METHODS

Nineteen children with bilateral PHL were studied. Age range 2-5 years (X = 53.04 months; SD = 9.54). All children were fitted with hearing aids according to auditory testing and they underwent a 1-year auditory habilitation period using the AVT approach. Acoustic analysis of voice including F0, shimmer, and jitter was performed at the onset and at the end of the auditory habilitation period. Final acoustic data were compared to a matched control group of 19 children, age range 2-5 years (X = 52.85; SD = 9.74) with normal hearing.

RESULTS

Mean fundamental frequency (F0) was significantly increased after AVT intervention. Shimmer and jitter significantly (P < 0.05) improved after the intervention period. However, despite the improvements, mean F0 at the end of the intervention period was still significantly (P < 0.05) decreased as compared to controls. Also, mean shimmer and jitter at the end of the habilitation period were still significantly (P < 0.05) higher as compared to controls.

CONCLUSIONS

The results of this preliminary study suggest that hearing aid use and auditory habilitation with AVT approach improved acoustic voice parameters of children with PHL. However, acoustic parameters persisted abnormal as compared to matched normal hearing controls. AVT approach and regular hearing aid use seem to be safe and reliable clinical tools for improving voice quality of children with PFL.

Long-term Average Speech Spectra of Postlingual Cochlear Implant Users

Long term average speech spectra (LTASS) is a commonly used voice analysis method for different purposes. This method offers an acoustic representation of the language in daily conservations. Results of that method can be altered by the deteriorations in the auditory feedback loop. Hearing losses occurred in the post lingual stage of life have some serious negative effects on the auditory feedback loop. Cochlear implantation may help these patients with regards to auditory feedback loop. Therefore, we aimed to evaluate the LTASS of cochlear implant users whose have a post lingual hearing loss. We assessed the LTASS of 24 cochlear implant users and compared our findings with normal hearing subjects. Our findings revealed that cochlear implant users have similar LTASS findings with normal hearing subjects. We conclude that cochlear implantation helps to the recovery of auditory feedback loop in patients with post lingual hearing losses.

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.

Objective Voice Analysis of Pediatric Cochlear Implant Recipients and Comparison With Hearing Aids Users and Hearing Controls

OBJECTIVES

Phonation is influenced by hearing as a feedback mechanism. The purpose of the present study was to compare selected acoustic parameters in children using cochlear implants (CIs), those using hearing aids (HA), and their normal-hearing (NH) peers.

METHODS

The participants were 15 children using CI (mean age: 72 months), 15 children using HA (mean age: 74 months), and 15 NH children (mean age: 77 months). The vowel /a/ was produced to measure perturbation and mean fundamental frequency. The six Persian vowels in /C_bVC_d/ were obtained to extract vowel duration. Data were analyzed by one-way analysis of variance.

RESULTS

Results revealed a statistically significant difference between the NH group and the HA group regarding fundamental frequency (F_2,51 = 3.443, P < 0.05), jitter local (F_2,51 = 1.629, P < 0.05), jitter local absolute (F_2,51 = 6.519, P < 0.001), jitter rap (F_2,51 = 7.151, P < 0.001), jitter ppq5 (F_2,51 = 5.894, P < 0.001), shimmer local (%) (F_2,51 = 8.070, P < 0.001), shimmer local (dB) (F_2,51 = 3.884, P < 0.05), shimmer apq3 (F_2,51 = 4.926, P < 0.05), shimmer apq5 (F_2,51 = 8.442, P < 0.001), and harmonic-to-noise ratio (F_2,51 = 4.117, P < 0.001). The mean values of the duration of all six vowels were significantly greater in children with CI and HA than in NH children (P < 0.001).

CONCLUSION

It seems that after 8 months of using CI, auditory control of voice production would be enabled. Furthermore, children with hearing impairment potentially regard vowel sound duration as a distinguishing feature, whereas in NH speakers, the duration has the least effect in vowel identification.

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.

Hearing performance and voice acoustics of cochlear implanted children

INTRODUCTION

The voice of hearing-impaired individuals has been described extensively, and exhibits abnormalities in quality, articulation and resonance. Having an understanding of the aspects that may have an impact on voice characteristics of cochlear implant users is important for users and for professionals in this field.

OBJECTIVE

To verify the existence of correlation between age, time of device use, voice detection threshold, hearing category score and language category score with acoustic data of voices of cochlear implanted children.

METHODS

Retrospective study. Fifty-one children ranging in age from 3 years to 5 years and 11 months who unilaterally used cochlear implants participated. Acoustic analysis of the sustained vowel/a/, sequential speech and spontaneous speech was performed. The results were correlated with demographic data and hearing test results.

RESULTS

Children with worse voice detection threshold showed higher frequency in the sustained vowel (p≤0.001) and in the spontaneous speech (p≤0.005).

CONCLUSION

There was a correlation between the voice detection threshold and the frequency values of the sustained vowel and spontaneous speech of the studied population.

An initial study of voice characteristics of children using two different sound coding strategies in comparison to normal hearing children

OBJECTIVE

To compare some perceptual and acoustic characteristics of the voices of children who use the advanced combination encoder (ACE) or fine structure processing (FSP) speech coding strategies, and to investigate whether these characteristics differ from children with normal hearing.

DESIGN

Acoustic analysis of the sustained vowel /a/ was performed using the multi-dimensional voice program (MDVP). Analyses of sequential and spontaneous speech were performed using the real time pitch. Perceptual analyses of these samples were performed using visual-analogic scales of pre-selected parameters.

STUDY SAMPLE

Seventy-six children from three years to five years and 11 months of age participated. Twenty-eight were users of ACE, 23 were users of FSP, and 25 were children with normal hearing.

RESULTS

Although both groups with CI presented with some deviated vocal features, the users of ACE presented with voice quality more like children with normal hearing than the users of FSP.

CONCLUSIONS

Sound processing of ACE appeared to provide better conditions for auditory monitoring of the voice, and consequently, for better control of the voice production. However, these findings need to be further investigated due to the lack of comparative studies published to understand exactly which attributes of sound processing are responsible for differences in performance.

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.

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.

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.

Relação entre voz e percepção de fala em crianças com implante coclear

TEMA: o uso do implante coclear resulta na otimização da percepção de fala, e conseqüentemente no desenvolvimento da linguagem, fala e voz de seus usuários, sendo que tem se mostrado uma das tecnologias mais efetivas e promissoras para remediar a perda auditiva. Entretanto, pouco tem sido estudado sobre a relação das habilidades auditivas com a voz de crianças implantadas. OBJETIVO: relacionar as habilidades de percepção de fala com características vocais de crianças usuárias de implante coclear. MÉTODO: foram realizadas análises perceptivo-auditiva e acústica da vogal sustentada /a/ e da contagem de números. Essa análise foi comparada a um teste de percepção de fala padronizado que avalia o reconhecimento de palavras, seus fonemas e consoantes. RESULTADOS: observou-se que quanto maior o reconhecimento de consoantes, maior a freqüência máxima, desvio padrão da freqüência fundamental e média de intensidade durante a fala encadeada, assim como a média da freqüência fundamental na análise da emissão da vogal /a/. Além disso, quanto maior o reconhecimento de consoantes menor o desvio geral da qualidade vocal e da ressonância. CONCLUSÃO: dentre as crianças com implante coclear, as que possuem melhor habilidade de percepção de sons da fala apresentam menores desvios perceptivo-auditivos na qualidade vocal.

Audio-vocal system regulation in children with autism spectrum disorders

Do children with autism spectrum disorders (ASD) respond similarly to perturbations in auditory feedback as typically developing (TD) children? Presentation of pitch-shifted voice auditory feedback to vocalizing participants reveals a close coupling between the processing of auditory feedback and vocal motor control. This paradigm was used to test the hypothesis that abnormalities in the audio-vocal system would negatively impact ASD compensatory responses to perturbed auditory feedback. Voice fundamental frequency (F(0)) was measured while children produced an /a/ sound into a microphone. The voice signal was fed back to the subjects in real time through headphones. During production, the feedback was pitch shifted (-100 cents, 200 ms) at random intervals for 80 trials. Averaged voice F(0) responses to pitch-shifted stimuli were calculated and correlated with both mental and language abilities as tested via standardized tests. A subset of children with ASD produced larger responses to perturbed auditory feedback than TD children, while the other children with ASD produced significantly lower response magnitudes. Furthermore, robust relationships between language ability, response magnitude and time of peak magnitude were identified. Because auditory feedback helps to stabilize voice F(0) (a major acoustic cue of prosody) and individuals with ASD have problems with prosody, this study identified potential mechanisms of dysfunction in the audio-vocal system for voice pitch regulation in some children with ASD. Objectively quantifying this deficit may inform both the assessment of a subgroup of ASD children with prosody deficits, as well as remediation strategies that incorporate pitch training.

Effect of Cochlear Implantation on Nasality in Children

Hypernasality is a commonly perceived characteristic of speech in deaf adults and children, but the mechanism of this abnormal nasal resonance is poorly understood. The impact of cochlear implantation on nasalance measures in children with severe auditory deprivation has not been previously reported. We conducted a study of nasality in 6 deaf children who had undergone cochlear implantation. Voice recordings were obtained before surgery and 6 months after activation of the implants. The MacKay-Kummer SNAP Test—which consists of a syllable-repetition subtest and a picture-cued subtest—was used to obtain nasalance scores for oral (bilabial, alveolar, velar, and sibilant) and nasal phonemes. Before cochlear implantation, mean nasalance scores were significantly higher than normal during the production of oral phonemes for both subtests (p ≤ 0.05). Six months after activation, the nasalance measures for all components of the syllable-repetition subtest had been restored to within 1 standard deviation of normal. For all oral phonemes of the picture-cued subtest, the elevated nasalance scores were consistently lower after cochlear implant activation, although the difference was statistically significant only for velar tasks. Nasalance scores for nasal phonemes were within 1 standard deviation of normal both before and after implant activation. Our study showed that cochlear implantation partially corrects elevated nasalance measures. Disturbances in nasal resonance may be caused in part by the inability of deaf speakers to monitor velopharyngeal valving with auditory feedback. The trend toward improved nasalance scores after implantation highlights the role of auditory feedback in monitoring velopharyngeal function. Visual biofeedback may be required to further normalize hypernasal speech in profoundly deaf children.

Change of phonation control after cochlear implantation

OBJECTIVE

To assess the influence of acquired auditory control on some voice parameters in deaf children and adults after cochlear implantation.

STUDY DESIGN

Prospective clinical study.

SETTING

Tertiary referral center.

PATIENTS

Twenty-nine prelingually deafened children and 11 postlingually deafened adults.

INTERVENTIONS

The samples of a vowel /a/ were analyzed with an Multi-Dimensional Voice Program (Kay Elemetrics Corporation, Lincoln Park, NJ) before and 6 to 12 months after the cochlear implantation.

MAIN OUTCOME MEASURES

The average fundamental frequency (F0), the short-term variation of F0 (JIT) and the amplitude (SH), the very long-term variation of F0 (vF0) and the amplitude (vAm), and the noise-to-harmonic ratio (NHR) were determined and compared for both age groups. The results of the acoustic analysis performed before the implantation were compared with the results after the implantation for children and adults.

RESULTS

Significantly greater JIT, SH, vF0, and vAm were detected in the children than in the adults before and after the implantation. The prelingually deafened children significantly improved the control of their phonation after 6 to 12 months' use of the cochlear implant (JIT: p=0.014, SH: p=0.011, vF0: p=0.014, vAm: p=0.031). In the postlingually deafened adults, no significant improvement was found in any of the studied voice parameters after the implantation. F0 showed little or no change after the implantation in children and adults.

CONCLUSION

As expected, the voice quality of the prelingually deafened children was significantly worse than that of the postlingually deafened adults. After cochlear implantation, the children significantly improved their short-term and long-term F0 and amplitude variability. In adults, no significant improvement was detected. We suppose that the improvement is a consequence not only of the acquired hearing control but also of the adaptation ability of neuromuscular phonation control and the maturing of these control mechanisms in children. In adults, better phonation quality in general and lesser improvement after the implantation can be the results of well-developed and stable phonation patterns.

Effects of Speech Noise on Vocal Fundamental Frequency Using Power Spectral Analysis

OBJECTIVE

To investigate the relationship between auditory function and vocal fundamental frequency (F0) using binaural masking with speech noise during sustained vowel vocalization.

DESIGN

Eight healthy subjects were instructed to vocalize the sustained vowel /a/ at the intensities of 65 to 75 dBA and 90 to 100 dBA as steadily as possible. The phonations without noise masking were compared with the phonations under masking with 85-dBA speech noise presented to both ears through headphones. The F0s were obtained by using autocorrelation of the voice signals and were converted to cents to form a F0 sequence. The power spectrum of the F0 sequence was then acquired using fast Fourier transformation.

RESULTS

A significant increase in the power spectrum in the frequency range of <3 Hz (p < 0.05, paired Student t-test) appeared under noise masking. A negative feedback control of the auditory system on F0 is suggested regarding F0 modulations of <3 Hz.

CONCLUSIONS

The auditory system helps control a stable F0 during sustained vowel production by decreasing F0 modulation at <3 Hz. Power spectral analysis of F0 may be used to assess the interaction between F0 production and auditory feedback.

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.