Perception of speech features by French-speaking children with cochlear implants

The impact of spectral and temporal processing on speech recognition in children with cochlear implants

While the relationships between spectral resolution, temporal resolution, and speech recognition are well defined in adults with cochlear implants (CIs), they are not well defined for prelingually deafened children with CIs, for whom language development is ongoing. This cross-sectional study aimed to better characterize these relationships in a large cohort of prelingually deafened children with CIs (N = 47; mean age = 8.33 years) by comprehensively measuring spectral resolution thresholds (measured via spectral modulation detection), temporal resolution thresholds (measured via sinusoidal amplitude modulation detection), and speech recognition (measured via monosyllabic word recognition, vowel recognition, and sentence recognition in noise via both fixed signal-to-noise ratio (SNR) and adaptively varied SNR). Results indicated that neither spectral or temporal resolution were significantly correlated with speech recognition in quiet or noise for children with CIs. Both age and CI experience had a moderate effect on spectral resolution, with significant effects for spectral modulation detection at a modulation rate of 0.5 cyc/oct, suggesting spectral resolution may improve with maturation. Thus, it is possible we may see an emerging relationship between spectral resolution and speech perception over time for children with CIs. While further investigation into this relationship is warranted, these findings demonstrate the need for new investigations to uncover ways of improving spectral resolution for children with CIs.

Nasal/Oral Vowel Perception in French-Speaking Children With Cochlear Implants and Children With Typical Hearing

PURPOSE

The present study investigates the perception of vowel nasality in French-speaking children with cochlear implants (CIs; CI group) and children with typical hearing (TH; TH group) aged 4-12 years. By investigating the vocalic nasality feature in French, the study aims to document more broadly the effects of the acoustic limitations of CI in processing segments characterized by acoustic cues that require optimal spectral resolution. The impact of various factors related to children's characteristics, such as chronological/auditory age, age of implantation, and exposure to cued speech, has been studied on performance, and the acoustic characteristics of the stimuli in perceptual tasks have also been investigated.

METHOD

Identification and discrimination tasks involving French nasal and oral vowels were administered to two groups of children: 13 children with CIs (CI group) and 25 children with TH (TH group) divided into three age groups (4-6 years, 7-9 years, and 10-12 years). French nasal vowels were paired with their oral phonological counterpart (phonological pairing) as well as to the closest oral vowel in terms of phonetic proximity (phonetic pairing). Post hoc acoustic analyses of the stimuli were linked to the performance in perception.

RESULTS

The results indicate an effect of the auditory status on the performance in the two tasks, with the CI group performing at a lower level than the TH group. However, the scores of the children in the CI group are well above chance level, exceeding 80%. The most common errors in identification were substitutions between nasal vowels and phonetically close oral vowels as well as confusions between the phoneme /u/ and other oral vowels. Phonetic pairs showed lower discrimination performance in the CI group with great variability in the results. Age effects were observed only in TH children for nasal vowel identification, whereas in children with CIs, a positive impact of cued speech practice and early implantation was found. Differential links between performance and acoustic characteristics were found within our groups, suggesting that in children with CIs, selective use of certain acoustic features, presumed to be better transmitted by the implant, leads to better perceptual performance.

CONCLUSIONS

The study's results reveal specific challenges in children with CIs when processing segments characterized by fine spectral resolution cues. However, the CI children in our study appear to effectively compensate for these difficulties by utilizing various acoustic cues assumed to be well transmitted by the implant, such as cues related to the temporal resolution of stimuli.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.25328704.

Processing of Plural Marking in Nouns by German-Speaking Children With Normal Hearing and Children With Cochlear Implants: An Eye-Tracking Study

PURPOSE

Our goal is to understand how the different types of plural marking are understood and processed by children with cochlear implants (CIs): (a) how does salience affect the processing of plural marking, (b) how is this processing affected by the incomplete signal provided by the CIs, and (c) is it linked to individual factors such as chronological age, vocabulary development, and phonological working memory?

METHOD

Sixteen children with CIs and 30 age-matched children with normal hearing (NH) participated in an eye-tracking study. Their task was to choose the corresponding picture to an auditorily presented singular or plural noun. Accuracy, reaction time, and gaze fixation were measured and analyzed with mixed-effect models.

RESULTS

Group differences were found in accuracy but not in reaction time or gaze fixation. Plural processing is qualitatively similar in children with CIs and children with NH, with more difficulties in processing plurals involving stem-vowel changes and less with those involving suffixes. Age effects indicate that processing abilities still evolve between 5 and 11 years, and processing is further linked to lexical development.

CONCLUSIONS

Our results indicate that early implantation seems to be beneficial for the acquisition of plural as indicated by very small between-group differences in processing and comprehension. Processing is furthermore affected by the type of material (i.e., phonetic, phonological, or morphological) used to mark plural and less so by their segmental salience. Our study emphasizes the need to take into account the form of the linguistic material in future investigations at higher levels of processing.

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.

Voice Onset Time of Greek Stops Productions by Greek Children with Cochlear Implants and Normal Hearing

INTRODUCTION

Research on voice onset time (VOT) production of stops in children with CI versus NH has reported conflicting results. Effects of age and place of articulation on VOT have not been examined for children with CI. The purpose of this study was to examine VOT production by Greek-speaking children with CI in comparison to NH controls, with a focus on the effects of age, type of stimuli, and place of articulation.

METHODS

Participants were 24 children with CI aged from 2;8 to 13;3 years and 24 age- and gender-matched children with NH. Words were elicited via a picture-naming task, and nonwords were elicited via a fast mapping procedure.

RESULTS

For voiced stops, children with CI showed longer VOT than children with NH, whereas VOT for voiceless stops was similar to that of NH peers. Also, in both voiced and voiceless stops, the VOT differed as a function of age and place of articulation across groups. Differences as a function of stimulus type were only noted for voiced stops across groups.

CONCLUSIONS

For the voiced stop consonants, which demand more articulatory effort, VOT production in children with CI was longer than in children with NH. For the voiceless stop consonants, VOT production in children with CI is acquired at a young age.

Speech rehabilitation in children with cochlear implants using a multisensory (French Cued Speech) or a hearing-focused (Auditory Verbal Therapy) approach

Introduction

Early exposure to a rich linguistic environment is essential as soon as the diagnosis of deafness is made. Cochlear implantation (CI) allows children to have access to speech perception in their early years. However, it provides only partial acoustic information, which can lead to difficulties in perceiving some phonetic contrasts. This study investigates the contribution of two spoken speech and language rehabilitation approaches to speech perception in children with CI using a lexicality judgment task from the EULALIES battery. Auditory Verbal Therapy (AVT) is an early intervention program that relies on auditory learning to enhance hearing skills in deaf children with CI. French Cued Speech, also called Cued French (CF), is a multisensory communication tool that disambiguates lip reading by adding a manual gesture.

Methods

In this study, 124 children aged from 60 to 140 months were included: 90 children with typical hearing skills (TH), 9 deaf children with CI who had participated in an AVT program (AVT), 6 deaf children with CI with high Cued French reading skills (CF+), and 19 deaf children with CI with low Cued French reading skills (CF-). Speech perception was assessed using sensitivity (d') using both the hit and false alarm rates, as defined in signal-detection theory.

Results

The results show that children with cochlear implants from the CF- and CF+ groups have significantly lower performance compared to children with typical hearing (TH) (p < 0.001 and p = 0.033, respectively). Additionally, children in the AVT group also tended to have lower scores compared to TH children (p = 0.07). However, exposition to AVT and CF seems to improve speech perception. The scores of the children in the AVT and CF+ groups are closer to typical scores than those of children in the CF- group, as evidenced by a distance measure.

Discussion

Overall, the findings of this study provide evidence for the effectiveness of these two speech and language rehabilitation approaches, and highlight the importance of using a specific approach in addition to a cochlear implant to improve speech perception in children with cochlear implants.

Phoneme Categorization in Prelingually Deaf Adult Cochlear Implant Users

PURPOSE

Phoneme categorization (PC) for voice onset time and second formant transition was studied in adult cochlear implant (CI) users with early-onset deafness and hearing controls.

METHOD

Identification and discrimination tasks were administered to 30 participants implanted before 4 years of age, 21 participants implanted after 7 years of age, and 21 hearing individuals.

RESULTS

Distinctive identification and discrimination functions confirmed PC within all groups. Compared to hearing participants, the CI groups generally displayed longer/higher category boundaries, shallower identification function slopes, reduced identification consistency, and reduced discrimination performance. A principal component analysis revealed that identification consistency, discrimination accuracy, and identification function slope, but not boundary location, loaded on a single factor, reflecting general PC performance. Earlier implantation was associated with better PC performance within the early CI group, but not the late CI group. Within the early CI group, earlier implantation age but not PC performance was associated with better speech recognition. Conversely, within the late CI group, better PC performance but not earlier implantation age was associated with better speech recognition.

CONCLUSIONS

Results suggest that implantation timing within the sensitive period before 4 years of age partly determines the level of PC performance. They also suggest that early implantation may promote development of higher level processes that can compensate for relatively poor PC performance, as can occur in challenging listening conditions.

Arabic phoneme-grapheme correspondence by non-native, deaf children with cochlear implants and normal hearing children

OBJECTIVE

This study aimed to compare the error patterns of Arabic phoneme-grapheme correspondence by a group of Malay children with cochlear implants (CIs) and normal hearing (NH) and the effects of the visual graphical features of Arabic graphemes (no-dot, single-dot, and multiple-dots) on the phoneme-grapheme correspondence.

METHODS

Participants were matched for hearing age (Mean, M = 7 ± 1.03 years) and duration of exposure to Arabic sounds (M = 2.7 ± 1.2 years). All 28 Arabic phonemes were presented through a loudspeaker and participants pointed to the graphemes associated with the presented phonemes.

RESULTS

A total of 336 and 616 tokens were collected for six children with CI and 11 NH children for each task, i.e., phonemes repetition and phoneme-grapheme correspondence. Both groups found it easier to repeat phonemes than the phoneme-grapheme correspondence. The children with CIs showed more confusion ([ظ, ز, ذ, ض, خ, ب, ه, س, ع, & ث] >10% correct scores) in phoneme-grapheme correspondence than the NH children ([ظ:14%] and [ث: 27%]). There was a significant interaction (p = 0.001) among the three visual graphical features and hearing status (CI and NH).

CONCLUSION

Our results infer that non-native Malay children with CIs and NH use different strategies to process the Arabic graphemes' visual features for phoneme-grapheme correspondence.

The Auditory Perception of Consonant Contrasts in Cochlear Implant Children

Background and ObjectivesA major part of speech perception is based on understanding and distinguishing between vocal cues in the speaker's speech. Consonants and vowels are vocal cues that can be affected by hearing impairment and their perception may thus be reduced or distorted. The present study aims to investigate the auditory perception of consonant contrasts in cochlear implant children. Materials and Methods The present cross-sectional, descriptive-analytical study was conducted on 24 cochlear implant children aged 9-13 selected through convenience sampling from schools and cochlear implant centers. A test of non-word pairs based on a study conducted by Khavar-Ghazlani was carried out to measure contrast in consonants, place of and manner of articulation and voicing. Results The results of the test showed that cochlear implant children scored lower in the perception of voicing compared to the other two features. No significant differences were observed between their perceptions of place of articulation and manner of articulation. Conclusion Cochlear implant children appear to have a poorer perception of voicing contrast compared to the other features, which may be due to the greater reliance of this feature on auditory signs.

Intraword Variability in Children With Auditory Brainstem Implants: A Longitudinal Comparison With Children With Cochlear Implants

PURPOSE

Intraword variability designates the phenomenon that a particular target word is produced variably by a child at one point in the child's development. In this study, the amount of intraword variability is studied longitudinally in children with auditory brainstem implants (ABIs). Auditory brainstem implantation is a relative recent technique in pediatric hearing restoration. Therefore, little is known about the phonological development of these children's speech.

METHOD

The intraword variability is investigated in three children with ABI, in comparison to children with cochlear implants, matched on lexical development. Intraword variability is measured using relative entropy in order to take into account the frequency distribution in children's productions.

RESULT

Results showed considerable variation between the three children with ABI. Still, all children had higher levels of intraword variability in their spontaneous speech productions as compared to children with cochlear implants.

CONCLUSION

It seems that children with ABI are lagging behind their phonological development in reference to children with cochlear implants.

The development of auditory temporal processing during the first year of life

OBJECTIVES

The processing of auditory temporal information is important for the extraction of voice pitch, linguistic information, as well as the overall temporal structure of speech. However, many aspects of its early development remain poorly understood. This paper reviews the development of auditory temporal processing during the first year of life when infants are acquiring their native language.

METHODS

First, potential mechanisms of neural immaturity are discussed in the context of neurophysiological studies. Next, what is known about infant auditory capabilities is considered with a focus on psychophysical studies involving non-speech stimuli to investigate the perception of temporal fine structure and envelope cues. This is followed by a review of studies involving speech stimuli, including those that present vocoded signals as a method of degrading the spectro-temporal information available to infant listeners.

RESULTS/CONCLUSION

This review suggests that temporal resolution may be well developed in the first postnatal months, but that the ability to use and process the temporal information in an efficient way along the entire auditory pathway is longer to develop. Those findings have crucial implications for the development of language abilities, especially for infants with hearing impairment who are using cochlear implants.

Allophonic perception of VOT contrasts in Spanish children with dyslexia

INTRODUCTION

Previous studies have evidenced a different mode of speech perception in dyslexia, characterized by the use of allophonic rather than phonemic units. People with dyslexia perceive phonemic features (such as voicing) less accurately than typical readers, but they perceive allophonic features (i.e., language-independent differences between speech sounds) more accurately.

METHOD

In this study, we investigated the perception of voicing contrasts in a sample of 204 Spanish children with or without dyslexia. Identification and discrimination data were collected for synthetic sounds varying along three different voice onset time (VOT) continua (ba/pa, de/te, and di/ti). Empirical data will be contrasted with a mathematical model of allophonic perception building up from neural oscillations and auditory temporal processing.

RESULTS

Children with dyslexia exhibited a general deficit in categorical precision; that is, they discriminated among phonemically contrastive pairs (around 0-ms VOT) less accurately than did chronological age controls, irrespective of the stimulus continuum. Children with dyslexia also exhibited a higher sensitivity in the discrimination of allophonic features (around ±30-ms VOT), but only for the stimulus continuum that was based on a nonlexical contrast (ba/pa).

CONCLUSION

Fitting the neural network model to the data collected for this continuum suggests that allophonic perception is due to a deficit in "subharmonic coupling" between high-frequency oscillations. Relationships with "temporal sampling framework" theory are discussed.

Children With Cochlear Implants Use Semantic Prediction to Facilitate Spoken Word Recognition

Purpose Children with cochlear implants (CIs) are more likely to struggle with spoken language than their age-matched peers with normal hearing (NH), and new language processing literature suggests that these challenges may be linked to delays in spoken word recognition. The purpose of this study was to investigate whether children with CIs use language knowledge via semantic prediction to facilitate recognition of upcoming words and help compensate for uncertainties in the acoustic signal. Method Five- to 10-year-old children with CIs heard sentences with an informative verb (draws) or a neutral verb (gets) preceding a target word (picture). The target referent was presented on a screen, along with a phonologically similar competitor (pickle). Children's eye gaze was recorded to quantify efficiency of access of the target word and suppression of phonological competition. Performance was compared to both an age-matched group and vocabulary-matched group of children with NH. Results Children with CIs, like their peers with NH, demonstrated use of informative verbs to look more quickly to the target word and look less to the phonological competitor. However, children with CIs demonstrated less efficient use of semantic cues relative to their peers with NH, even when matched for vocabulary ability. Conclusions Children with CIs use semantic prediction to facilitate spoken word recognition but do so to a lesser extent than children with NH. Children with CIs experience challenges in predictive spoken language processing above and beyond limitations from delayed vocabulary development. Children with CIs with better vocabulary ability demonstrate more efficient use of lexical-semantic cues. Clinical interventions focusing on building knowledge of words and their associations may support efficiency of spoken language processing for children with CIs. Supplemental Material https://doi.org/10.23641/asha.14417627.

The impact of alphabetic literacy on the perception of speech sounds

The aim of the present study was to evaluate the impact of literacy on phoneme perception. It built on previous research by using more controlled stimuli than in former studies and by independently examining the impacts of literacy and age on phoneme perception. Participants were adult and children beginning readers, and skilled adult readers. They were presented with identification and discrimination tasks, using a voicing continuum. In addition to examining their categorical perception of speech sounds and the precision of phonemic categories, participants' literacy level was carefully evaluated. The results confirmed that neither age nor literacy modulated categorical perception. However, level of literacy did have a significant impact on the precision of phonemic categories, which was independent from the influence of age.

Consonant and vowel articulation accuracy in younger and middle-aged Spanish healthy adults

Children acquire vowels earlier than consonants, and the former are less vulnerable to speech disorders than the latter. This study explores the hypothesis that a similar contrast exists later in life and that consonants are more vulnerable to ageing than vowels. Data was obtained with two experiments comparing the speech of Younger Adults (YAs) and Middle–aged Adults (MAs). In the first experiment an Automatic Speech Recognition (ASR) system was trained with a balanced corpus of 29 YAs and 27 MAs. The productions of each speaker were obtained in a Spanish language word (W) and non–word (NW) repetition task. The performance of the system was evaluated with the same corpus used for training using a cross validation approach. The ASR system recognized to a similar extent the Ws of both groups of speakers, but it was more successful with the NWs of the YAs than with those of the MAs. Detailed error analysis revealed that the MA speakers scored below the YA speakers for consonants and also for the place and manner of articulation features; the results were almost identical in both groups of speakers for vowels and for the voicing feature. In the second experiment a group of healthy native listeners was asked to recognize isolated syllables presented with background noise. The target speakers were one YA and one MA that had taken part in the first experiment. The results were consistent with those of the ASR experiment: the manner and place of articulation were better recognized, and vowels and voicing were worse recognized, in the YA speaker than in the MA speaker. We conclude that consonant articulation is more vulnerable to ageing than vowel articulation. Future studies should explore whether or not these early and selective changes in articulation accuracy might be caused by changes in speech perception skills (e.g., in auditory temporal processing).

Development of fricative production in French-speaking school-aged children using cochlear implants and children with normal hearing

In the course of productive phonological development, fricatives are among the last speech sounds to emerge and to be mastered by children, probably because of the high degree of articulatory precision they require or because of difficulties with their perception. Children with cochlear implants (CI) face additional difficulties with fricative perception, since high spectral frequency components are shown to be especially difficult to perceive with a cochlear implant. Studying fricative production in children with CIs allows to study how the partial transmission of speech sounds by cochlear implants influences children's speech production, and therefore to explore how perceptual abilities influence the late stages of phonological development. This acoustic study focuses on fricative production at three places of articulation (i.e., /f/, /s/ and /ʃ/), comparing productions by two groups of children (20 children with normal hearing (NH) vs. 13 children with CIs, all aged 5;7 to 10;7 years), and taking into account their consistency in coarticulation and the stability of their production across two different tasks (word-repetition and picture-naming). Statistical analyses were carried out by means of linear mixed-effect models. The results show that while both groups produce /ʃ/ with similar acoustic characteristics, between-group differences are found for /f/ and /s/. Furthermore, effects of consonant-vowel coarticulation are found for children with NH, and are absent for children with CIs. Effects of chronological age are only found for children with CIs (production in older children with CIs nearing that of children with NH). Our study shows that the development of fricative production of five- to 11-year-old children with CIs is affected by the children's hearing abilities and late access to auditory information. These limitations however do not prevent the children from eventually reaching a consistency similar to that of children with NH, as suggested by the fact that their production is still evolving during that age span. The results also show that the acquisition of coarticulation strategies can be impeded by degraded or delayed access to audio.

Discrimination and identification of lexical tones and consonants in Mandarin-speaking children using cochlear implants

Mandarin-speaking adults using cochlear implants (CI) experience more difficulties in perceiving lexical tones than consonants. This problem may result from the fact that CIs provide relatively sufficient temporal envelope information for consonant perception in quiet environments, but do not convey the fine spectro-temporal information considered to be necessary for accurate pitch perception. Another possibility is that Mandarin speakers with post-lingual hearing loss have developed language-specific use of these acoustic cues, impeding lexical tone processing under CI conditions. To investigate this latter hypothesis, syllable discrimination and word identification abilities for Mandarin consonants (place and manner) and lexical-tone contrasts (tones 1 vs 3 and 1 vs 2) were measured in 15 Mandarin-speaking children using CIs and age-matched children with normal hearing (NH). In the discrimination task, only children using CIs exhibited significantly lower scores for consonant place contrasts compared to other contrasts, including lexical tones. In the word identification task, children using CIs showed lower performance for all contrasts compared to children with NH, but they both showed specific difficulties with tone 1 vs 2 contrasts. This study suggests that Mandarin-speaking children using CIs are able to discriminate and identify lexical tones and, perhaps more surprisingly, have more difficulties when discriminating consonants.

Patterns of recognition of Arabic consonants by non-native children with cochlear implants and normal hearing

OBJECTIVE

This study examined the patterns of recognition of Arabic consonants, via information transmission analysis for phonological features, in a group of Malay children with normal hearing (NH) and cochlear implants (CI).

METHOD

A total of 336 and 616 acoustic tokens were collected from six CI and 11 NH Malay children, respectively. The groups were matched for hearing age and duration of exposure to Arabic sounds. All the 28 Arabic consonants in the form of consonant-vowel /a/ were presented randomly twice via a loudspeaker at approximately 65 dB SPL. The participants were asked to repeat verbally the stimulus heard in each presentation.

RESULTS

Within the native Malay perceptual space, the two groups responded differently to the Arabic consonants. The dispersed uncategorized assimilation in the CI group was distinct in the confusion matrix (CM), as compared to the NH children. Consonants /ħ/, /tˁ/, /sˁ/ and /ʁ/ were difficult for the CI children, while the most accurate item was /k/ (84%). The CI group transmitted significantly reduced information, especially for place feature transmission, then the NH group (p < 0.001). Significant interactions between place-hearing status and manner-hearing status were also obtained, suggesting there were information transmission differences in the pattern of consonants recognition between the study groups.

CONCLUSION

CI and NH Malay children may be using different acoustic cues to recognize Arabic sounds, which contribute to the different assimilation categories' patterns within the Malay perceptual space.

Recognition of Spanish consonants in 8-talker babble by children with cochlear implants, and by children and adults with normal hearing

This paper presents the results of closed-set recognition task for 80 Spanish consonant-vowel sounds in 8-talker babble. Three groups of subjects participated in the study: a group of children using cochlear implants (CIs; age range: 7-13), an age-matched group of children with normal hearing (NH), and a group of adults with NH. The speech-to-noise ratios at which the participants recognized 33% of the target consonants were +7.8 dB, -3 dB, and -6 dB, respectively. In order to clarify the qualitative differences between the groups, groups were matched for the percentage of recognized syllables. As compared with the two groups with NH, the children with CIs: (1) produced few "I do not know" responses; (2) frequently selected the voiced stops (i.e., /b, d, ɡ/) and the most energetic consonants (i.e., /l, r, ʝ, s, ʧ/); (3) showed no vowel context effects; and (4) had a robust voicing bias. As compared with the adults with NH, both groups of children showed a fronting bias in place of articulation errors. The factors underlying these error patterns are discussed.

Phonological awareness in German-speaking preschool children with cochlear implants - 3 case examples

OBJECTIVE

The aim was to explore PA skills German-speaking preschool children with cochlea implants (CIs) and how these skills may be related to their speech and language skills.

METHODS

Three monolingual German-speaking pre-school children aged 5;04-6;01 with bilateral CIs were tested. Their cognitive, speech and language skills were assessed. Six subtests of a standardized PA test battery were administered (i.e. rhyme identification, rhyme production; phoneme identification- input and -output; phoneme blending-input and -output).

RESULTS

All three children showed distinctive PA profiles. One boy, who had no spoken language deficits, struggled to complete the rhyme tasks but performed well on three phoneme tasks. However, he showed a discrepancy between expressive and receptive phoneme blending skills, scoring poorly on the expressive subtest. The second boy, who displayed grammar comprehension and expressive vocabulary difficulties, showed a mixed profile, with a below average performance on rhyme production. The girl who had significant speech and language deficits scored below average on all six PA subtests.

CONCLUSIONS

PA profiles in children with CI vary considerably and PA testing should include a range of different PA tasks. The assumed link between spoken language deficits and PA difficulties shown in children with normal hearing could be confirmed.

Analysis of Spanish consonant recognition in 8-talker babble

This paper presents the results of a closed-set recognition task for 80 Spanish consonant-vowel sounds (16 C × 5 V, spoken by 2 talkers) in 8-talker babble (-6, -2, +2 dB). A ranking of resistance to noise was obtained using the signal detection d' measure, and confusion patterns were analyzed using a graphical method (confusion graphs). The resulting ranking indicated the existence of three resistance groups: (1) high resistance: /ʧ, s, ʝ/; (2) mid resistance: /r, l, m, n/; and (3) low resistance: /t, θ, x, ɡ, b, d, k, f, p/. Confusions involved mostly place of articulation and voicing errors, and occurred especially among consonants in the same resistance group. Three perceptual confusion groups were identified: the three low-energy fricatives (i.e., /f, θ, x/), the six stops (i.e., /p, t, k, b, d, ɡ/), and three consonants with clear formant structure (i.e., /m, n, l/). The factors underlying consonant resistance and confusion patterns are discussed. The results are compared with data from other languages.

Visual speech alters the discrimination and identification of non-intact auditory speech in children with hearing loss

OBJECTIVES

Understanding spoken language is an audiovisual event that depends critically on the ability to discriminate and identify phonemes yet we have little evidence about the role of early auditory experience and visual speech on the development of these fundamental perceptual skills. Objectives of this research were to determine 1) how visual speech influences phoneme discrimination and identification; 2) whether visual speech influences these two processes in a like manner, such that discrimination predicts identification; and 3) how the degree of hearing loss affects this relationship. Such evidence is crucial for developing effective intervention strategies to mitigate the effects of hearing loss on language development.

METHODS

Participants were 58 children with early-onset sensorineural hearing loss (CHL, 53% girls, M = 9;4 yrs) and 58 children with normal hearing (CNH, 53% girls, M = 9;4 yrs). Test items were consonant-vowel (CV) syllables and nonwords with intact visual speech coupled to non-intact auditory speech (excised onsets) as, for example, an intact consonant/rhyme in the visual track (Baa or Baz) coupled to non-intact onset/rhyme in the auditory track (/-B/aa or/-B/az). The items started with an easy-to-speechread/B/or difficult-to-speechread/G/onset and were presented in the auditory (static face) vs. audiovisual (dynamic face) modes. We assessed discrimination for intact vs. non-intact different pairs (e.g., Baa:/-B/aa). We predicted that visual speech would cause the non-intact onset to be perceived as intact and would therefore generate more same-as opposed to different-responses in the audiovisual than auditory mode. We assessed identification by repetition of nonwords with non-intact onsets (e.g.,/-B/az). We predicted that visual speech would cause the non-intact onset to be perceived as intact and would therefore generate more Baz-as opposed to az- responses in the audiovisual than auditory mode.

RESULTS

Performance in the audiovisual mode showed more same responses for the intact vs. non-intact different pairs (e.g., Baa:/-B/aa) and more intact onset responses for nonword repetition (Baz for/-B/az). Thus visual speech altered both discrimination and identification in the CHL-to a large extent for the/B/onsets but only minimally for the/G/onsets. The CHL identified the stimuli similarly to the CNH but did not discriminate the stimuli similarly. A bias-free measure of the children's discrimination skills (i.e., d' analysis) revealed that the CHL had greater difficulty discriminating intact from non-intact speech in both modes. As the degree of HL worsened, the ability to discriminate the intact vs. non-intact onsets in the auditory mode worsened. Discrimination ability in CHL significantly predicted their identification of the onsets-even after variation due to the other variables was controlled.

CONCLUSIONS

These results clearly established that visual speech can fill in non-intact auditory speech, and this effect, in turn, made the non-intact onsets more difficult to discriminate from intact speech and more likely to be perceived as intact. Such results 1) demonstrate the value of visual speech at multiple levels of linguistic processing and 2) support intervention programs that view visual speech as a powerful asset for developing spoken language in CHL.

On the nature of the speech perception deficits in children with autism spectrum disorders

Previous studies have claimed to show deficits in the perception of speech sounds in autism spectrum disorders (ASD). The aim of the current study was to clarify the nature of such deficits. Children with ASD might only exhibit a lesser amount of precision in the perception of phoneme categories (CPR deficit). However, these children might further present an allophonic mode of speech perception, similar to the one evidenced in dyslexia, characterised by enhanced discrimination of acoustic differences within phoneme categories. Allophonic perception usually gives rise to a categorical perception (CP) deficit, characterised by a weaker coherence between discrimination and identification of speech sounds. The perceptual performance of ASD children was compared to that of control children of the same chronological age. Identification and discrimination data were collected for continua of natural vowels, synthetic vowels, and synthetic consonants. Results confirmed that children with ASD exhibit a CPR deficit for the three stimulus continua. These children further exhibited a trend toward allophonic perception that was, however, not accompanied by the usual CP deficit. These findings confirm that the commonly found CPR deficit is also present in ASD. Whether children with ASD also present allophonic perception requires further investigations.

Sensitive periods and language in cochlear implant users

This study explores the hypothesis that the existence of a short sensitive period for lower-level speech perception/articulation skills, and a long one for higher-level language skills, may partly explain the language outcomes of children with cochlear implants (CIs). The participants were fourteen children fitted with a CI before their second birthday. Data about their language skills and the environmental conditions (e.g. Family Involvement in rehabilitation) were obtained over a period of three years. Age at implantation correlated exclusively with the ratio of errors of place of articulation, a phonological feature for which CIs provide insufficient information. The degree of Family Involvement was significantly correlated with the remaining language measures. We conclude that small plasticity reductions affecting lower-level skills may partly explain the difficulties of some CI users in developing language.

Rapid learning of minimally different words in five- to six-year-old children: effects of acoustic salience and hearing impairment

This study investigates the role of acoustic salience and hearing impairment in learning phonologically minimal pairs. Picture-matching and object-matching tasks were used to investigate the learning of consonant and vowel minimal pairs in five- to six-year-old deaf children with a cochlear implant (CI), and children of the same age with normal hearing (NH). In both tasks, the CI children showed clear difficulties with learning minimal pairs. The NH children also showed some difficulties, however, particularly in the picture-matching task. Vowel minimal pairs were learned more successfully than consonant minimal pairs, particularly in the object-matching task. These results suggest that the ability to encode phonetic detail in novel words is not fully developed at age six and is affected by task demands and acoustic salience. CI children experience persistent difficulties with accurately mapping sound contrasts to novel meanings, but seem to benefit from the relative acoustic salience of vowel sounds.

Syntagmatic and paradigmatic development of cochlear implanted children in comparison with normally hearing peers up to age 7

OBJECTIVE

Grammatical development is shown to be delayed in CI children. However, the literature has focussed mainly on one aspect of grammatical development, either morphology or syntax, and on standard tests instead of spontaneous speech. The aim of the present study was to compare grammatical development in the spontaneous speech of Dutch-speaking children with cochlear implants and normally hearing peers. Both syntagmatic and paradigmatic development will be assessed and compared with each other.

METHOD

Nine children with cochlear implants were followed yearly between ages 2 and 7. There was a cross-sectional control group of 10 normally hearing peers at each age. Syntactic development is measured by means of Mean Length of Utterance (MLU), morphological development by means of Mean Size of Paradigm (MSP). This last measure is relatively new in child language research.

RESULTS

MLU and MSP of children with cochlear implants lag behind that of their normally hearing peers up to age 4 and up to age 6 respectively. By age 5, CI children catch up on MSP and by age 7 they caught up on MLU.

CONCLUSION

Children with cochlear implants catch up with their normally hearing peers for both measures of syntax and morphology. However, it is shown that inflection is earlier age-appropriate than sentence length in CI children. Possible explanations for this difference in developmental pace are discussed.

Infants Discriminate Voicing and Place of Articulation With Reduced Spectral and Temporal Modulation Cues

PURPOSE

This study assessed the role of spectro-temporal modulation cues in the discrimination of 2 phonetic contrasts (voicing and place) for young infants.

METHOD

A visual-habituation procedure was used to assess the ability of French-learning 6-month-old infants with normal hearing to discriminate voiced versus unvoiced (/aba/-/apa/) and labial versus dental (/aba/-/ada/) stop consonants. The stimuli were processed by tone-excited vocoders to degrade frequency-modulation cues while preserving: (a) amplitude-modulation (AM) cues within 32 analysis frequency bands, (b) slow AM cues only (<16 Hz) within 32 bands, and (c) AM cues within 8 bands.

RESULTS

Infants exhibited discrimination responses for both phonetic contrasts in each processing condition. However, when fast AM cues were degraded, infants required a longer exposure to vocoded stimuli to reach the habituation criterion.

CONCLUSIONS

Altogether, these results indicate that the processing of modulation cues conveying phonetic information on voicing and place is "functional" at 6 months. The data also suggest that the perceptual weight of fast AM speech cues may change during development.

Computer-assisted reading intervention with a phonics approach for children using cochlear implants or hearing aids

The present study examined computer-assisted reading intervention with a phonics approach for deaf and hard of hearing (DHH) children in Sweden using cochlear implants or hearing aids, or a combination of both. The study included 48 children, 5, 6 and 7 years of age. Sixteen children with normal hearing (NH) served as a reference group. The first purpose of the study was to compare NH and DHH children's reading ability at pre and post-intervention. The second purpose was to investigate effects of the intervention. Cognitive and demographic factors were analyzed in relation to reading improvement. Results showed no statistically significant difference for reading ability at the group level, although NH children showed overall higher reading scores at both test points. Age comparisons revealed a statistically significant higher reading ability in the NH 7-year-olds compared to the DHH 7-year-olds. The intervention proved successful for word decoding accuracy, passage comprehension and as a reduction of nonword decoding errors in both NH and DHH children. Reading improvement was associated with complex working memory and phonological processing skills in NH children. Correspondent associations were observed with visual working memory and letter knowledge in the DHH children. Age was the only demographic factor that was significantly correlated with reading improvement. The results suggest that DHH children's beginning reading may be influenced by visual strategies that might explain the reading delay in the older children.

The emergence of productive speech and language in Spanish-learning paediatric cochlear implant users

It has been proposed that cochlear implant users may develop robust categorical perception skills, but that they show limited precision in perception. This article explores if a parallel contrast is observable in production, and if, despite acquiring typical linguistic representations, their early words are inconsistent. The participants were eight Spanish-learning deaf children implanted before their second birthday. Two studies examined the transition from babbling to words, and the one-word period. Study 1 found that the participants used the same sound types in babbling and in words, indicating that production is guided by stored motor patterns. No clear evidence of inconsistent production was observed. Study 2 found that in the one-word period CI users develop typical prosodic representations, but that their productions are highly unstable. Results are discussed in terms of the role of auditory feedback for the development of productive language skills.

Computer-assisted training of phoneme-grapheme correspondence for children who are deaf and hard of hearing: effects on phonological processing skills

OBJECTIVE

Examine deaf and hard of hearing (DHH) children's phonological processing skills in relation to a reference group of children with normal hearing (NH) at two baselines pre intervention. Study the effects of computer-assisted phoneme-grapheme correspondence training in the children. Specifically analyze possible effects on DHH children's phonological processing skills.

METHODS

The study included 48 children who participated in a computer-assisted intervention study, which focuses on phoneme-grapheme correspondence. Children were 5, 6, and 7 years of age. There were 32 DHH children using cochlear implants (CI) or hearing aids (HA), or both in combination, and 16 children with NH. The study had a quasi-experimental design with three test occasions separated in time by four weeks; baseline 1 and 2 pre intervention, and 3 post intervention. Children performed tasks measuring lexical access, phonological processing, and letter knowledge. All children were asked to practice ten minutes per day at home supported by their parents.

RESULTS

NH children outperformed DHH children on the majority of tasks. All children improved their accuracy in phoneme-grapheme correspondence and output phonology as a function of the computer-assisted intervention. For the whole group of children, and specifically for children with CI, a lower initial phonological composite score was associated with a larger phonological change between baseline 2 and post intervention. Finally, 18 DHH children, whereof 11 children with CI, showed specific intervention effects on their phonological processing skills, and strong effect sizes for their improved accuracy of phoneme-grapheme correspondence.

CONCLUSION

For some DHH children phonological processing skills are boosted relatively more by phoneme-grapheme correspondence training. This reflects the reciprocal relationship between phonological change and exposure to and manipulations of letters.

Phonetic processing during the acquisition of new words in 3-to-6-year-old French-speaking deaf children with cochlear implants

The present study explores phonetic processing in deaf children with cochlear implants (CIs) when they have to learn phonetically similar words. Forty-six 34-to-78-month-old French-speaking deaf children with CIs were tested on 16 different trials. In each trial, they were first trained with two word-object pairings, and then a third object was presented and labeled with one of the familiar words. Children were asked to match one of the previously labeled objects with the third (same-labeled) object. Each pair of words contrasted on either the initial consonant or the first vowel by one or several phonetic features. The results show that deaf children with CIs are able to establish a new referential link between a word and an object. However, their performance is lower than that previously observed in normal-hearing children (NH). In such a situation, they process contrasts involving several phonetic features correctly, but show difficulties with minimal contrasts. The ability to recruit fine phonetic sensitivity during word learning appears to be influenced mainly by duration of implant use, with an overall increase of performance during the 3 years after implantation. There was no chronological age effect, nor age at implantation effect on the quality of processing. Difficulty with minimal contrasts and the absence of any age at implantation effects in this age range are discussed in light of recent studies on lexical development.

LEARNING OUTCOMES

After reading this article, the reader will be able to recognize the perceptual skills of children with cochlear implants and distinguish those perceptual features that are difficult for the children to perceive.