Mandarin-speaking Children With Cochlear Implants Face Challenges in Using F0 Expansion to Express Contrastive Focus.

OBJECTIVES: Children with cochlear implants (CIs) face challenges in perceiving fundamental frequency (F0) information because CIs do not transmit F0 effectively. In Mandarin, F0 can contrast meanings at the word level, that is, via lexical tones with distinct F0 contours, and signal contrastive relations between words at the utterance-level, that is, via contrastive focus with expanded F0 range and longer duration. Mandarin-speaking children with CIs have been reported to face challenges in producing distinct F0 contours across tones, but early implantation facilitates tonal acquisition. However, it is still unclear if utterance-level prosody, such as contrastive focus, is also challenging for these children, and if early implantation also offers benefits for focus production. Therefore, this study asked how accurately children with CIs can produce contrastive focus, and if early implantation leads to more accurate focus production, with acoustic patterns approaching that of children with typical hearing (TH). DESIGN: Participants included 55 Mandarin-speaking children (3 to 7 years) with CIs and 55 age-matched children with TH. Children produced noun phrases with and without contrastive focus, such as RED-COLORED cat versus red-colored cat . Three adult native listeners perceptually scored the productions as correct or incorrect. The "correct" productions were then acoustically analyzed in terms of F0 range and duration. RESULTS: Based on the perceptual scores, children with CIs produced focus with significantly lower accuracy (38%) than their TH peers (84%). The acoustic analysis on their "correct" productions showed that children with TH used both F0 and duration to mark focus, producing focal syllables with an expanded F0 range and long duration, and postfocal syllables with a reduced F0 range and short duration. However, children with CIs differed from children with TH in that they produced focal syllables with long duration but not an expanded F0 range, although they produced postfocal syllables with a reduced F0 range and short duration like their TH peers. In addition, early implantation correlated with the percept of more accurate focus productions and better use of F0 range in focal marking. CONCLUSIONS: This study finds that Mandarin-speaking children with CIs are still learning to apply appropriate acoustic cues to contrastive focus. The challenge appears to lie in the use of an expanded F0 range to mark focus, probably related to the limited transmission of F0 information through the CI devices. These findings thus have implications for parents and those working with children with CIs, showing that utterance-level prosody also requires speech remediation, and underscores the critical role of identifying problems early in the acquisition of F0 functions in Mandarin, not only at the word level but also at the utterance-level.

Children with hearing loss can use subject-verb agreement to predict during spoken language processing.

Rapid processing of spoken language is aided by the ability to predict upcoming words using both semantic and syntactic cues. However, although children with hearing loss (HL) can predict upcoming words using semantic associations, little is known about their ability to predict using syntactic dependencies such as subject-verb (SV) agreement. This study examined whether school-aged children with hearing aids and/or cochlear implants can use SV agreement to predict upcoming nouns when processing spoken language. Although they did demonstrate prediction with plural SV agreement, they did so more slowly than their normal hearing (NH) peers. This may be due to weaker grammatical representations given that function words and grammatical inflections typically have lower perceptual salience. Thus, a better understanding of morphosyntactic representations in children with HL, and their ability to use these for prediction, sheds much-needed light on the online language processing challenges and abilities of this population.

The production of /s/-stop clusters by pre-schoolers with hearing loss.

Producing word-initial /s/-stop clusters can be a challenge for English-speaking pre-schoolers. For children with hearing loss (HL), fricatives can be also difficult to perceive, raising questions about their production and representation of /s/-stop clusters. The goal of this study was therefore to determine if pre-schoolers with HL can produce and represent the /s/ in word-initial /s/-stop clusters, and to compare this to their normal hearing (NH) peers. Based on both acoustic and perceptual analysis, we found that children with HL had little /s/-omission, suggesting that their phonological representation of these clusters closely aligns with that of their NH peers.

Uncovering the development of linguistic knowledge in lesser studied languages.

There has recently been an increased interest in studying the language development of non-western languages. This is not new - it began in 1960's and continued into the 1980's and 1990's. The current renewed interest is much welcomed, and will benefit from many of the experimental methods and theoretical insights developed over the past decades.

The acoustic realization of contrastive focus by 6-year-old Australian English-speaking children.

Children as young as five have some ability to produce contrastive focus [Wells et al. (2004) J. Child Lang. 31, 749-778]. However, adult listeners' ability to identify the location of contrastive focus depends on whether the speech came from a 4-, 7-, or 11-year-old [Patel and Brayton (2009) J. Speech. Lang. Hear. Res. 52, 790-801]. Recent acoustic studies have also reported the use of F0 vs duration in contrastive focus productions by American English-speaking 2-year-olds [Thorson and Morgan (2021) J. Child Lang. 48, 541-568] and 4-year-olds [Wonnacott and Watson (2008) Cognition 107, 1093-1101], respectively. This study, therefore, evaluated the extent to which older 6-year-olds, with more language experience, used F0 and/or duration when producing contrastive focus, and compared this to adult speech. Monosyllabic and disyllabic adjective + noun targets (e.g., green ball) in utterance medial and final position were elicited from 20 Australian English-speaking 6-year-olds and 14 adults in adjective focus and noun focus conditions. Although both adults and children used high F0, only adults consistently used word and stressed syllable duration as well. This suggests that children may master the different acoustic cues to contrastive focus at different stages of development, with late cue integration.

Produced, but not 'productive': Mandarin-speaking pre-schoolers' challenges acquiring L2 English plural morphology.

It is often assumed that pre-schoolers learn a second language (L2) with ease, even for structures that are absent in their L1, such as Mandarin-speaking pre-schoolers learning L2 English grammatical inflections (e.g., ducks, horses). However, while the results from Study 1 showed that such learners can imitate plural words (age = 3;5, N = 20), Studies 2 and 3 showed that they cannot yet generate or comprehend plural morphology (Study 2: age = 4;8, N = 20; Study 3: age = 4;1, N = 20), raising questions about when this is achieved. These findings have important implications for school readiness, as well as for identifying those at risk of developmental language disorders.

Jellybeans or Jelly, Beans ? 5-6-year-olds can identify the prosody of compounds but not lists.

Learning to use word versus phrase level prosody to identify compounds from lists is thought to be a protracted process, only acquired by 11 years (Vogel & Raimy, 2002). However, a recent study has shown that 5-year-olds can use prosodic cues other than stress for these two structures in production, at least for early-acquired noun-noun compounds (Yuen et al., 2021). This raises the question of whether children this age can also use naturally-produced prosody to identify noun-noun compounds from their list forms in comprehension. The results show that 5-6-year-olds (N = 28) can only identify compounds. Unlike adults, children as a group could not use boundary cues to identify lists and were significantly slower in their processing compared to adults. This suggests that the acquisition of word level prosody may precede the acquisition of phrase level prosody, i.e., some higher-level aspects of phrasal prosody may take longer to acquire.

Longer Cochlear Implant Experience Leads to Better Production of Mandarin Tones for Early Implanted Children.

OBJECTIVES: Children with cochlear implants (CIs) face challenges in acquiring tones, since CIs do not transmit pitch information effectively. It has been suggested that longer CI experience provides additional benefits for children implanted early, enabling them to achieve language abilities similar to that of normal-hearing (NH) children (Colletti 2009). Mandarin is a tonal language with four lexical tones and a neutral tone (T0), characterized by distinct pitch and durational patterns. It has been suggested that early implantation (i.e., before 2 years) greatly benefits the acquisition of Mandarin tones by children with CIs (Tang et al. 2019c). In this study, we extend those findings to investigate the effect of CI experience on the acquisition of Mandarin tones for children implanted early. We asked the extent to which they were able to produce distinct pitch and durational patterns of both lexical tones and T0 as a function of CI experience, and the extent to which their tonal productions were acoustically like that of NH children. DESIGN: Forty-four NH 3-year olds and 28 children implanted with CIs between 1 and 2 years, aged 3 to 7, were recruited. The children with CIs were grouped according to the length of CI experience: 3 to 6 years, 2 to 3 years, and 1 to 2 years. Lexical tone and T0 productions were elicited using a picture-naming task. Tonal productions from the children with CIs were acoustically analyzed and compared with those from the NH children. RESULTS: Children with 3 to 6 years of CI experience were able to produce distinct pitch and durational patterns for both lexical tones and T0, with NH-like acoustic realizations. Children with 2 to 3 years of CI experience were also able to produce the expected tonal patterns, although their productions were not yet NH-like. Those with only 1 to 2 years of CI experience, however, were not yet able to produce the distinct acoustic patterns for either lexical tones or T0. CONCLUSIONS: These results provide acoustic evidence demonstrating that, when Mandarin-speaking children are implanted before the age of 2, only those with 3 to 6 years of experience were able to produce NH-like tones, including both lexical tone and T0. Children with shorter CI experience (less than 3 years) were unable to produce distinct acoustic patterns for the different tones. This suggests that at least 3 years of CI experience is still needed for early implanted children to acquire tonal distinctions similar to those of NH 3-year olds.

Temporal cues to onset voicing contrasts in Australian English-speaking children.

Voicing contrasts are lexically important for differentiating words in many languages (e.g., "bear" vs "pear"). Temporal differences in the voice onset time (VOT) and closure duration (CD) contribute to the voicing contrast in word-onset position. However, little is known about the acoustic realization of these voicing contrasts in Australian English-speaking children. This is essential for understanding the challenges faced by those with language delay. Therefore, the present study examined the VOT and CD values for word-initial stops as produced by 20 Australian English-speaking 4-5-year-olds. As anticipated, these children produced a systematic distinction between voiced and voiceless stops at all places of articulation (PoAs). However, although the children's VOT values for voiced stops were similar to those of adults, their VOTs for voiceless stops were longer. Like adults, the children also had different CD values for voiced and voiceless categories; however, these were systematically longer than those of adults. Even after adjusting for temporal differences by computing proportional ratios for the VOT and CD, children's voicing contrasts were not yet adultlike. These results suggest that children of this age are still developing appropriate timing and articulatory adjustments for voicing contrasts in the word-initial position.

Acoustic cues to coda stop voicing contrasts in Australian English-speaking children.

While voicing contrasts in word-onset position are acquired relatively early, much less is known about how and when they are acquired in word-coda position, where accurate production of these contrasts is also critical for distinguishing words (e.g., dog vs. dock). This study examined how the acoustic cues to coda voicing contrasts are realized in the speech of 4-year-old Australian English-speaking children. The results showed that children used similar acoustic cues to those of adults, including longer vowel duration and more frequent voice bar for voiced stops, and longer closure and burst durations for voiceless stops along with more frequent irregular pitch periods. This suggests that 4-year-olds have acquired productive use of the acoustic cues to coda voicing contrasts, though implementations are not yet fully adult-like. The findings have implications for understanding the development of phonological contrasts in populations for whom these may be challenging, such as children with hearing loss.

Child-directed and overheard input from different speakers in two distinct cultures.

Despite the fact that in most communities interaction occurs between the child and multiple speakers, most previous research on input to children focused on input from mothers. We annotated recordings of Sesotho-learning toddlers living in non-industrial Lesotho in South Africa, and French-learning toddlers living in urban regions in France. We examined who produced the input (mothers, other children, adults), how much input was child directed, and whether and how it varied across speakers. As expected, mothers contributed most of the input in the French recordings. However, in the Sesotho recordings, input from other children was more common than input from mothers or other adults. Child-directed speech from all speakers in both cultural groups showed similar qualitative modifications. Our findings suggest that input from other children is prevalent and has similar features as child-directed from adults described in previous work, inviting cross-cultural research into the effects of input from other children.

Five-year-olds produce prosodic cues to distinguish compounds from lists in Australian English.

Although previous research has indicated that five-year-olds can use acoustic cues to disambiguate compounds (N1 + N2) from lists (N1, N2) (e.g., 'ice-cream' vs. 'ice, cream') (Yoshida & Katz, 2004, 2006), their productions are not yet fully adult-like (Wells, Peppé & Goulandris, 2004). The goal of this study was to examine this issue in Australian English-speaking children, with a focus on their use of F0, word duration, and pauses. Twenty-four five-year-olds and 20 adults participated in an elicited production experiment. Like adults, children produced distinct F0 patterns for the two structures. They also used longer word durations and more pauses in lists compared to compounds, indicating the presence of a boundary in lists. However, unlike adults, they also inappropriately inserted more pauses within the compound, suggesting the presence of a boundary in compounds as well. The implications for understanding children's developing knowledge of how to map acoustic cues to prosodic structures are discussed.

Depression and Anxiety in the Postnatal Period: An Examination of Infants' Home Language Environment, Vocalizations, and Expressive Language Abilities.

This longitudinal study investigated the effects of maternal emotional health concerns, on infants' home language environment, vocalization quantity, and expressive language skills. Mothers and their infants (at 6 and 12 months; 21 mothers with depression and or anxiety and 21 controls) provided day-long home-language recordings. Compared with controls, risk group recordings contained fewer mother-infant conversational turns and infant vocalizations, but daily number of adult word counts showed no group difference. Furthermore, conversational turns and infant vocalizations were stronger predictors of infants' 18-month vocabulary size than depression and anxiety measures. However, anxiety levels moderated the effect of conversational turns on vocabulary size. These results suggest that variability in mothers' emotional health influences infants' language environment and later language ability.

Comprehension of the copula: preschoolers (and sometimes adults) ignore subject-verb agreement during sentence processing.

Subject-verb (SV) agreement helps listeners interpret the number condition of ambiguous nouns (The sheep is/are fat), yet it remains unclear whether young children use agreement to comprehend newly encountered nouns. Preschoolers and adults completed a forced choice task where sentences contained singular vs. plural copulas (Where is/are the [novel noun(s)]?). Novel nouns were either morphologically unambiguous (tup/tups) or ambiguous (/geks/ = singular: gex / plural: gecks). Preschoolers (and some adults) ignored the singular copula, interpreting /ks/-final words as plural, raising questions about the role of SV agreement in learners' sentence comprehension and the status of is in Australian English.

Preschoolers' developing comprehension of the plural: The effects of number and allomorphic variation.

Previous intermodal preferential looking (IPL) studies have found that children learning English acquire knowledge of plural allomorphs incrementally. The segmental plural /-s/ (e.g., cats) is understood at 24 months of age, whereas the syllabic plural /-əz/ (e.g., buses) is not comprehended until 36 months. Production studies also show ongoing challenges with the syllabic plural /-əz/, suggesting a prolonged weaker representation for this allomorph. IPL studies also suggest that children do not understand the singular, which has no overt marking, until 36 months of age. However, the status of children's developing representations of the singular has been largely unstudied. The current study, therefore explored 116 3- and 4-year-olds' developing comprehension of novel singular and plural words, where the plurals were inflected with segmental and syllabic plural allomorphs. Results found that children were equally proficient at identifying novel plurals of both allomorph types, increasing accuracy with age. However, children's accuracy with novel singulars did not increase with age, raising questions about the representation of null morphology. Children's equal accuracy across plural allomorphs is more consistent with rule-based models of morphological representation than those proposing morphology as an emergent property of the lexicon. However, neither model completely accounts for the developmental differences found between singular and plural.

Acquisition of weak syllables in tonal languages: acoustic evidence from neutral tone in Mandarin Chinese.

Weak syllables in Germanic and Romance languages have been reported to be challenging for young children, with syllable omission and/or incomplete reduction persisting till age five. In Mandarin Chinese, neutral tone (T0) involves a weak syllable with varied pitch realizations across (preceding) tonal contexts and short duration. The present study examined how and when T0 was acquired by 108 Beijing Mandarin-speaking children (3-5 years) relative to 33 adult controls. Lexicalized (familiar) and non-lexicalized (unfamiliar) T0 words were elicited in different preceding tonal contexts. Unlike previous reports, the present study revealed that children as young as three years have already developed a phonological category for T0, exhibiting contextually conditioned tonal realizations of T0 for both familiar and unfamiliar items. However, mastery of adult-like pitch and duration implementation of T0 is a protracted process not completed until age five. The implications for the acquisition of weak syllables more generally are discussed.

A program to respond to otitis media in remote Australian Aboriginal communities: a qualitative investigation of parent perspectives.

BACKGROUND: Indigenous infants and children in Australia, especially in remote communities, experience early and chronic otitis media (OM) which is difficult to treat and has lifelong impacts in health and education. The LiTTLe Program (Learning to Talk, Talking to Learn) aimed to increase infants' access to spoken language input, teach parents to manage health and hearing problems, and support children's school readiness. This paper aimed to explore caregivers' views about this inclusive, parent-implemented early childhood program for 0-3 years in an Aboriginal community health context. METHODS: Data from in-depth, semi-structured interviews with 9 caregivers of 12 children who had participated in the program from one remote Aboriginal community in the Northern Territory are presented. Data were analysed thematically. Caregivers provided overall views on the program. In addition, three key areas of focus in the program are also presented here: speech and language, hearing health, and school readiness. RESULTS: Caregivers were positive about the interactive speech and language strategies in the program, except for some strategies which some parents found alien or difficult: such as talking slowly, following along with the child's topic, using parallel talk, or baby talk. Children's hearing was considered by caregivers to be important for understanding people, enjoying music, and detecting environmental sounds including signs of danger. Caregivers provided perspectives on the utility of sign language and its benefits for communicating with infants and young children with hearing loss, and the difficulty of getting young community children to wear a conventional hearing aid. Caregivers were strongly of the opinion that the program had helped prepare children for school through familiarising their child with early literacy activities and resources, as well as school routines. But caregivers differed as to whether they thought the program should have been located at the school itself. CONCLUSIONS: The caregivers generally reported positive views about the LiTTLe Program, and also drew attention to areas for improvement. The perspectives gathered may serve to guide other cross-sector collaborations across health and education to respond to OM among children at risk for OM-related disability in speech and language development.

Discourse Strategies and the Production of Prosody by Prelingually Deaf Adolescent Cochlear Implant Users.

OBJECTIVES: The purpose of this study is to assess the use of discourse strategies and the production of prosody by prelingually deaf adolescent users of cochlear implants (CIs) when participating in a referential communication task. We predict that CI users will issue more directives (DIRs) and make less use of information requests (IRs) in completing the task than their normally hearing (NH) peers. We also predict that in signaling these IRs and DIRs, the CI users will produce F0 rises of lesser magnitude than the NH speakers. DESIGN: Eight prelingually deaf adolescent CI users and 8 NH adolescents completed a referential communication task, where participants were required to direct their interlocutor around a map. Participants were aged from 12.0 to 14.2 years. The mean age at implantation for the CI group was 2.1 years (SD 0.9). The use of IRs, DIRs, acknowledgments, and comments was compared between the two groups. The use and magnitude of fundamental frequency (F0) rises on IRs and DIRs was also compared. RESULTS: The CI users differed from the NH speakers in how they resolved communication breakdown. The CI users showed a preference for repeating DIRs, rather than seeking information as did the NH speakers. A nonparametric Mann-Whitney U test indicated that the CI users issued more DIRs (U = 8, p = 0.01), produced fewer IRs (U = 13, p = 0.05) and fewer acknowledgments (U = 5, p = 0.003) than their NH counterparts. The CI users also differed in how they used F0 rises as a prosodic cue to signal IRs and DIRs. The CI users produced larger F0 rises on DIRs than on IRs, a pattern opposite to that displayed by the NH speakers. An independent samples t-test revealed that the CI users produced smaller rises on IRs compared with those produced by the NH speakers [t(12) = -2.762, p = 0.02]. CONCLUSIONS: The CI users differed from the NH speakers in how they resolved communication breakdown. The CI users showed a preference for repeating DIRs, rather than seeking information to understand their interlocutor's point of view. Their use of prosody to signal discourse function also differed from their NH peers. These differences may indicate a lack of understanding of how prosody is used to signal discourse modality by the CI users. This study highlights the need for further research focused on the interaction of prosody, discourse, and language comprehension.

Phonetic enhancement of Mandarin vowels and tones: Infant-directed speech and Lombard speech.

Speech units are reported to be hyperarticulated in both infant-directed speech (IDS) and Lombard speech. Since these two registers have typically been studied separately, it is unclear if the same speech units are hyperarticulated in the same manner between these registers. The aim of the present study is to compare the effect of register on vowel and tone modification in the tonal language Mandarin Chinese. Vowel and tone productions were produced by 15 Mandarin-speaking mothers during interactions with their 12-month-old infants during a play session (IDS), in conversation with a Mandarin-speaking adult in a 70 dBA eight-talker babble noise environment (Lombard speech), and in a quiet environment (adult-directed speech). Vowel space expansion was observed in IDS and Lombard speech, however, the patterns of vowel-shift were different between the two registers. IDS displayed tone space expansion only in the utterance-final position, whereas there was no tone space expansion in Lombard speech. The overall pitch increased for all tones in both registers. The tone-bearing vowel duration also increased in both registers, but only in utterance-final position. The difference in speech modifications between these two registers is discussed in light of speakers' different communicative needs.

Acoustic characteristics of Punjabi retroflex and dental stops.

The phonological category "retroflex" is found in many Indo-Aryan languages; however, it has not been clearly established which acoustic characteristics reliably differentiate retroflexes from other coronals. This study investigates the acoustic phonetic properties of Punjabi retroflex /ʈ/ and dental /ʈ̪/ in word-medial and word-initial contexts across /i e a o u/, and in word-final context across /i a u/. Formant transitions, closure and release durations, and spectral moments of release bursts are compared in 2280 stop tokens produced by 30 speakers. Although burst spectral measures and formant transitions do not consistently differentiate retroflexes from dentals in some vowel contexts, stop release duration, and total stop duration reliably differentiate Punjabi retroflex and dental stops across all word contexts and vocalic environments. These results suggest that Punjabi coronal place contrasts are signaled by the complex interaction of temporal and spectral cues.