The Lombard effect in children with cochlear implants: suprasegmental aspects

Children with cochlear implants (CI) communicate in noisy environments, such as in classrooms, where multiple talkers and reverberation are present. Speakers compensate for noise via the 'Lombard effect'. The present study examined the Lombard effect on the intensity and duration of stressed vowels in the speech of children with Cochlear Implants (CIs) as compared to children with Normal Hearing (NH), focusing on the effects of speech-shaped noise (SSN) and speech-shaped noise with reverberation (SSN+Reverberation). The sample consisted of 7 children with CIs and 7 children with NH, aged 7-12 years. Regarding intensity, a) children with CIs produced stressed vowels with an overall greater intensity across acoustic conditions as compared to NH peers, b) both groups increased their stressed vowel intensity for all vowels from Quiet to both noise conditions, and c) children with NH further increased their intensity when reverberation was added to SSN, esp. for the vowel/u/. Regarding duration, longer stressed vowels were produced by children with CIs as compared to NH in Quiet and SSN conditions but the effect was retained only for the vowels/i/,/o/and/u/when reverberation was added to noise. The SSN+Reverberation condition induced systematic lengthening in stressed vowels for children with NH. Furthermore, although greater intensity and duration ratios of stressed/unstressed syllables were observed for children with NH as compared to CIs in Quiet condition, they diminished with noise. The differences observed across groups have implications for speaking in classroom noise.

Does Lexical Stress Pattern Affect Learning and Producing New Words in Greek for Children With Cochlear Implants?

PURPOSE

Τhe lexical stress pattern (trochaic vs. iambic) may affect various aspects of word learning and word production in children with cochlear implants (CIs). This study aimed to investigate lexical stress effects in word learning by Greek-speaking children with CIs.

METHOD

A word learning paradigm, consisting of a word production and a word identification task, was used. A test list of eight pairs of disyllabic nonwords with identical phonological composition and contrasting lexical stress (eight trochaic and eight iambic), along with their referent pictured objects, was constructed and administered to 22 Greek-speaking children with CIs (ages 4;6-12;3 [years;months]) with normal nonverbal IQ and to 22 age-matched controls with normal hearing (NH) and no other difficulties.

RESULTS

Overall, children with CIs exhibited lower performance than their hearing peers in all word-learning tasks, regardless of lexical stress pattern. Specifically, they identified significantly fewer words and exhibited significantly lower accuracy in word production than those of the controls. In the group with CIs, lexical stress pattern affected their production of words but not their word identification. Children with CIs showed more accurate production of iambic than trochaic words, a fact attributed to better vowel production. Yet, production of stress was less accurate for iambic than for trochaic words. Μoreover, stress assignment of iambic words was highly correlated with speech and language tests in children with CIs.

CONCLUSIONS

Greek children with CIs exhibited lower performance in the word-learning task administered than children with NH did. In addition, the performance of children with CIs indicated a dissociation between the perception and production mechanisms and revealed complex relations between the segmental and prosodic aspects of words. Preliminary findings suggest that stress assignment in iambic words can serve as an indicator of speech and language growth.

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.

Psychometric Properties of the Cyprus Lexical List in the Greek Language for Infants and Preschool Children and Preliminary Results

The aim of this study was to evaluate the psychometric properties of the adapted Cyprus Greek Lexical List a-CYLEX (GR) in a sample of 194 Greek toddlers from the island of Crete with Standard Modern Greek (SMG) as their primary language. The a-CYLEX (GR) is a parental report checklist for assessing the receptive and expressive vocabulary skills of children aged 12 months to 3:6 years. Concurrent validity of the instrument was tested via correlations with the adapted Greek version of the Receptive One-Word Picture Vocabulary Test-II (ROWPVT-II), which was administered to 124 SMG-speaking children between the ages of 2 and 3:6 years. Test-retest reliability was tested by administering the instrument two times within a 2-week interval to 59 parents (30.41% of the total sample). Statistical analyses provided strong evidence for the high internal consistency and test-retest reliability of the a-CYLEX (GR). The role of the demographic variables in vocabulary performance and the frequency of each a-CYLEX (GR) word category by age were also investigated. In conclusion, the a-CYLEX (GR) is a parental report checklist that can be used by clinicians who are interested in assessing receptive and expressive vocabulary of children during toddlerhood.

Sonority-Related Novel Word Learning Ability of Children With Cochlear Implants With Optimal Oral Language Exposure

OBJECTIVES

The present study investigated how children with cochlear implants (CIs), with optimal exposure to oral language, perform on sonority-related novel word learning tasks. By optimal oral language exposure, we refer to bilateral cochlear implantation below the age of 2 years. Sonority is the relative perceptual prominence/loudness of speech sounds of the same length, stress, and pitch. The present study is guided by a previous study that investigated the sonority-related novel word learning ability of a group of children with CIs, in the Greek language, of which the majority were implanted beyond the age of 2 unilaterally.

DESIGN

A case-control study with 15 Dutch-speaking participants in each of the three groups, i.e., children with CIs, normal-hearing children (NHC), and normal-hearing adults, was conducted using a sonority-related novel "CVC" word learning task. All children with CIs are implanted before the age of 2 years with preimplant hearing aids. Thirteen out of the 15 children had bilateral CIs. The CVC words were constructed according to four sonority conditions, where N is nonsonorous and S is a sonorous phoneme: NSN, NSS, SSN, and SSS. Outcome measures were accuracy and reaction times (RTs). In addition, the Peabody picture vocabulary test and the digit span forward test were administered to the children.

RESULTS

There were no statistical differences in accuracy or RTs between the children groups on the overall score and across the different conditions. However, children with CIs, unlike NHC, scored statistically less accurately and with longer RTs relative to normal-hearing adults, on the overall task. Within-group comparisons showed that none of the groups performed statistically differently on any of the conditions. The NHC showed higher receptive vocabulary scores relative to children with CIs. In addition, the group of children with CIs entailed a statistically significantly higher number of children with "weak" short-term memory.

CONCLUSIONS

Children with CIs who have optimal oral language exposure showed age-appropriate sonority-related novel word learning abilities and strategies relative to their NH peers. However, children with CIs continue to show lower receptive vocabulary scores than NHC, despite the equivalent novel word learning ability. This suggests that children with CIs may have difficulties in retaining newly learned words. Future work should look into possible causes of the gap in performance. This would eventually aid in rehabilitation tailored to the needs of the individual.

Nasalance and perceived voice changes in patients undergoing septoplasty and turbinate hypertrophy reduction

PURPOSE

The purpose of this study was to investigate the changes in voice nasality after septoplasty and turbinate hypertrophy reduction and to evaluate the effect of these changes on patients' voice-related quality of life.

METHODS

Sixty patients with nasal obstruction symptoms caused by septal deviation and inferior turbinate hypertrophy who underwent septoplasty and inferior turbinate hypertrophy reduction and 25 healthy controls were included. Active anterior rhinomanometry and acoustic rhinometry were utilized for the evaluation of nasal patency and nasometry was used for quantitative assessment of nasalance. All participants completed validated questionnaires for assessing nasal obstruction symptom severity, psychological status and the impact of voice performance on their quality of life preoperatively and 6 months after septoplasty.

RESULTS

Patients presented preoperatively statistically significantly lower nasalance scores and higher VHI scores than controls (p < 0.05). Septoplasty and inferior turbinate hypertrophy reduction led to improvement of nasalance for the nasal text and the physical subscale of the VHI scores. Postoperatively, there were no statistically significant differences in nasalance and VHI scores between patients and controls. Significant correlations were found only for the baseline and the postoperative nasalance scores for the nasal text and the total nasal cavity volume (p < 0.05). Postoperatively, patients who presented significant improvement of nasal obstruction symptoms and resolution of stress levels were more likely to positively evaluate the impact of their voice quality on their daily life (OR: 2.32, 95% CI 1.08-5.15, p = 0.041 and OR: 3.06, 95% CI 1.15-7.04, p = 0.038, respectively).

CONCLUSION

Septoplasty and inferior turbinate hypertrophy reduction may increase the nasal resonance, but in the long term, this change appears not to be significant enough. The severity of nasal obstruction symptoms and psychological status mainly affect the patients' perceptual assessment regarding the effect of voice performance on their quality of life.

Perception of Synthetic and Natural Speech by Adults with Visual Impairments

This study investigated the intelligibility and comprehensibility of natural speech in comparison to synthetic speech. The results demonstrate the type of errors; the relationship between intelligibility and comprehensibility; and the correlation between intelligibility and comprehensibility and key factors, such as the frequency of use of text-to-speech systems.

Coarticulatory dynamics in Greek disyllables produced by young adults with and without hearing loss

Hearing loss affects both speech perception and production with detrimental effects on various speech characteristics including coarticulatory dynamics. The aim of the present study is to explore consonant-to-vowel (C-to-V) and vowel-to-vowel (V-to-V) coarticulation in magnitude, direction and temporal extent in the speech of young adult male and female speakers of Greek with normal hearing (NH) and hearing impairment (HI). Nine intelligible speakers with profound HI, using conventional hearing aids, and five speakers with NH produced /pV₁CV₂/ disyllables, with the point vowels /i, a, u/ and the consonants /p, t, s/, stressed either on the first or the second syllable. Formant frequencies F1 and F2 were measured in order to examine C-to-V effects at vowel midpoint and V-to-V effects at vowel onset, midpoint and offset. The acoustic and statistical analyses revealed similarities but also significant differences regarding coarticulatory patterns of the two groups. Interestingly, prevalence of anticipatory coarticulation effects in alveolar contexts was observed for speakers with HI. Findings are interpreted on account of possible differences in articulation strategies between the two groups and with reference to current coarticulatory models.

Teachers' screening estimations of speech-language impairments in primary school children in Nepal

BACKGROUND

The prevalence of speech-language impairments in children have been estimated for several languages, primarily in developed countries. However, prevalence data is lacking for developing countries, such as Nepal.

AIMS

(1) To obtain teacher estimates of incidence and overall prevalence of speech-language impairments and its subtypes as a function of gender, age and grade level; and (2) to validate the screening instrument on Nepalese children.

METHODOLOGY

The adapted teachers' screening instrument, namely adapted Teachers' Speech and Language Referral Checklist (a-TSLRC), was administered in 2776 (690 and 2086) primary school children aged 5;00-11;11 years (mean = 8;11 years). The screening was conducted at four different points in time, i.e. Incidences I and II, and each incidence consisted of a testing and a retesting phase. Prior to this, teachers were trained in forum meetings, and an information sheet containing an overview of speech-language impairments, and guidelines/criteria for marking the occurrence of speech-language impairments in the TSLRC were disseminated.

OUTCOMES & RESULTS

Overall prevalence of speech-language impairments in children was estimated as 8.11%. Specifically, overall speech problems were estimated as 4.68%, and language problems as 8.0%. Additionally, the prevalence by subtypes of speech-language impairments as categorized in the TSLRC were reported to be 2.95% for an articulation/phonological problems, 2.09% for stuttering, 3.42% for a voice problems, 4.97% for a receptive language problems and 7.74% for an expressive language problems. The internal consistency among items was sufficient and a good intra-rater reliability was obtained.

CONCLUSIONS & IMPLICATIONS

The study indicates that the overall results of speech-language impairments in children via the adapted in-Nepalese criterion-referenced instrument are supported by international studies. In addition, justifiable reliability and validity was obtained. Therefore, based on these overall evidence, this instrument can be useful for the screening of speech-language impairments in primary school children in Nepal.

Knowledge, experience and practice of SLTs regarding (re)habilitation in deaf children with cochlear implants

OBJECTIVES

To assess the knowledge, experience and practices of speech and language therapists (SLTs) in Greece regarding children with cochlear implants.

METHODS

A special designed questionnaire was originally completed electronically by 313 SLTs via surveymonkey platform.

RESULTS

From the 313 respondents 35% had worked with implanted children, 37% received course training and 44% had participated in post-graduate seminars. Although 96% believe that there are differences in the management of these children, almost 47% of the participants did not have adequate knowledge on the candidacy criteria for implantation and 70% regarding the available technology for implanted children. Knowledge and skills on CI were better for those SLTs who worked with hearing-impairment. Diverse practice models were noted. Interestingly, more than 87% of the participants advocated toward further training and supervision in the field, even the ones who had less than extensive knowledge in working with CI. As for practice, a lack of organizational interdisciplinary structure became evident.

CONCLUSIONS

There is a growing need for well organized professional training and team networks for SLTs in order for them to further improve their knowledge and service delivery to implanted children.

Nasalance norms in Greek adults

The purposes of this study were to derive nasalance norms for monolingual Greek speakers, to examine nasalance scores as a function of gender and to draw cross-linguistic comparisons based on normative data. Participants read aloud a corpus of linguistic material, consisting of (1) a nasal text, an oral text and a balanced text; (2) a set of nasal sentences and four sets of oral sentences and (3) repetitions of each of 12 syllable types (8 oral and 4 nasal). The last two sets of material corpus were based on an adaptation of the Simplified Nasometric Assessment Procedures Test (SNAP test) test ( MacKay and Kummer, 1994 ) in Greek, called the G-SNAP test. Eighty monolingual healthy young adult speakers of Greek, 40 males (mean age = 21 years) and 40 females (mean age = 20.5 years), with normal hearing and speech characteristics and unremarkable history were included in the study. The Nasometer (model 6200-3) was used to derive nasalance scores. Mean normative nasalance for spoken Greek was 25.50%, based on the G-oronasal text (with 8.6% nasals). Nasalance scores did not differ significantly with respect to gender. Finally, spoken Greek consistently yielded lower nasalance scores than other languages examined in past work. The aforementioned normative data on nasalance of young adult speakers of Greek are valid across gender and have direct clinical utility as they provide valuable reference information for the diagnosis and management of Greek adults with resonance disorders caused by velar dysfunction.

Adapting a receptive vocabulary test for preschool-aged Greek-speaking children

BACKGROUND

Receptive vocabulary is an important measure for language evaluations. Therefore, norm-referenced receptive vocabulary tests are widely used in several languages. However, a receptive vocabulary test has not yet been normed for Modern Greek.

AIMS

To adapt an American English vocabulary test, the Receptive One-Word Picture Vocabulary Test-II (ROWPVT-II), for Modern Greek for use with Greek-speaking preschool children.

METHODS & PROCEDURES

The list of 170 English words on ROWPVT-II was adapted by (1) developing two lists (A and B) of Greek words that would match either the target English word or another concept corresponding to one of the pictured objects in the four-picture array; and (2) determining a developmental order for the chosen Greek words for preschool-aged children. For the first task, adult word frequency measures were used to select the words for the Greek wordlist. For the second task, 427 children, 225 boys and 202 girls, ranging in age from 2;0 years to 5;11 years, were recruited from urban and suburban areas of Greece. A pilot study of the two word lists was performed with the aim of comparing an equal number of list A and list B responses for each age group and deriving a new developmental list order.

OUTCOMES & RESULTS

The relative difficulty of each Greek word item, that is, its accuracy score, was calculated by taking the average proportion of correct responses across ages for that word. Subsequently, the word accuracy scores in the two lists were compared via regression analysis, which yielded a highly significant relationship (R(2) = 0.97; p < 0.0001) and a few outlier pairs (via residuals). Further analysis used the original relative ranking order along with the derived ranking order from the average accuracy scores of the two lists in order to determine which word item from the two lists was a better fit. Finally, new starting levels (basals) were established for preschool ages.

CONCLUSIONS & IMPLICATIONS

The revised word list can serve as the basis for adapting a receptive vocabulary test for Greek preschool-aged children. Further steps need to be taken when testing larger numbers of 2;0 to 5;11-year-old children on the revised word list for determination of norms. This effort will facilitate early identification and remediation of language disorders in Modern Greek-speaking children.

Development of voice onset time in standard-Greek and Cypriot-Greek-speaking preschoolers

The current investigation examined the development of voice onset time (VOT) in Standard-Greek (SG) and Cypriot-Greek (CG)-speaking children at age levels 2;0-2;5, 2;6-2;11, 3;0-3;5, and 3;6-4;0 years. SG presents with a two-way voicing contrast (voiced and voiceless unaspirated stops) whereas CG is a three-way contrast dialect containing voiceless unaspirated, voiceless aspirated, and pre-voiced stops. A cross-sectional design was used. The main goals were: (1) to determine the age at which Greek and Cypriot Greek children acquire voicing contrasts, and (2) to examine the mechanism used during the process of acquisition. Stimuli included pseudo words in minimal pair contrasts differing in stop voicing (e.g. ['gaga] vs ['kaka]). Children were taught the target words using fast mapping procedures. Each member within a word pair referred to an unfamiliar object. Audio-recorded samples were analysed from wide-band spectrograms. Results indicated a greater overall variation of voicing patterns for children than adults, in both Greek and Cypriot VOT contrasts. Greek children acquired consistent pre-voicing and short lag aspiration patterns very early on, achieving adult values for VOT contrasts for alveolar and for velar places of articulation as early as 2;0-2;5 years old. On the contrary, a developmental lag in the acquisition of voicing contrasts was noted for Cypriot children as compared to the Greek counterparts. Accounts about the developmental differences among Greek and Cypriot children with respect to the adult VOT contrasts are discussed.

Teacher perceptions of communication impairment at screening stage in preschool children living in Patras, Greece

The general aim was to obtain piloting data for a series of experiments about the prevalence of communication impairment in preschool children in Greece. At this screening stage of the overall project, teacher perceptions of communication impairment in 57 kindergartens servicing 1113 children were examined via a questionnaire distributed in the urban region of Patras. The specific research goals were (1) to screen for specific categories of communication impairment such as articulation/phonology, receptive language, expressive language and pragmatics, hearing, stuttering, and voice, as they appear in the mainstreamed kindergarten population and (2) to offer comparative information on sex differences in communication impairment(s). The information was gathered by administration of a Greek-adapted version of the Communication Checklist for Pre-school Teachers, which was administered three times to obtain validity and reliability measures. The results were analysed separately for two studies (original and follow-up) and indicated teacher estimates of 14.4-18.7% for communication impairment in kindergarten children of the Patras region. Prevalence was higher for boys than for girls. Analysis of specific communication areas revealed that prevalence varies according to gender and category of communicative impairment. The limitations and follow-up needs of this study are discussed.

A comparison of intergestural patterns in deaf and hearing adult speakers: implications from an acoustic analysis of disyllables

Coarticulation studies in speech of deaf individuals have so far focused on intrasyllabic patterning of various consonant-vowel sequences. In this study, both inter- and intrasyllabic patterning were examined in disyllables /symbol see text #CVC/ and the effects of phonetic context, speaking rate, and segment type were explored. Systematic observation of F2 and durational measurements in disyllables minimally contrasting in vocalic ([i], [u,][a]) and in consonant ([b], [d]) context, respectively, was made at selected locations in the disyllable, in order to relate inferences about articulatory adjustments with their temporal coordinates. Results indicated that intervocalic coarticulation across hearing and deaf speakers varied as a function of the phonetic composition of disyllables (b_b or d_d). The deaf speakers showed reduced intervocalic coarticulation for bilabial but not for alveolar disyllables compared to the hearing speakers. Furthermore, they showed less marked consonant influences on the schwa and stressed vowel of disyllables compared to the hearing controls. Rate effects were minimal and did not alter the coarticulatory patterns observed across hearing status. The above findings modify the conclusions drawn from previous studies and suggest that the speech of deaf and hearing speakers is guided by different gestural organization.