An ultrasound study of the development of lingual coarticulation during childhood

This is the peer-reviewed but unedited manuscript version of the following article: Zharkova, N. (2018) An ultrasound study of the development of lingual coarticulation during childhood. Phonetica, 75 (3), pp. 245-271. https://doi.org/10.1159/000485802. The final, published version is available at http://www.karger.com/?doi=10.1159/000485802Background/Aims. There is growing evidence that coarticulation development is protracted and segment-specific, and yet very little information is available on the changes in the extent of coarticulation across different phonemes throughout childhood. This study describes lingual coarticulatory patterns in six age groups of Scottish English speaking children between three and thirteen years old. Methods. Vowel-on-consonant anticipatory coarticulation was analysed using ultrasound imaging data on tongue shape from four consonants that differ in the degree of constraint, i.e., the extent of articulatory demand, on the tongue. Results. Consonant-specific age-related patterns are reported, with consonants that have more demands on the tongue reaching adolescent-like levels of coarticulation in older age groups. Within-speaker variability in tongue shape decreases with increasing age. Conclusion. Reduced coarticulation in the youngest age group may be due to insufficient tongue differentiation. Immature patterns for lingual consonants in 5-to-11-year-olds are explained by the goal of producing the consonant target overriding the goal of coarticulating the consonant with the following vowel.casl75pub5328pub

The articulatory basis of positional asymmetries in phonological acquisition

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Linguistics and Philosophy, 2009.Cataloged from PDF version of thesis.Includes bibliographical references (p. 250-276).Child phonological processes that lack counterparts in adult phonological typology have long posed a problem for formal modeling of phonological acquisition. This dissertation investigates child-specific processes with a focus on the phenomenon of neutralization in strong position, whereby children preferentially neutralize phonemic contrast in precisely those contexts seen to support maximal contrast in adult systems. These processes are difficult to model without making incorrect predictions for adult typology. Here, it is argued that all genuinely child-specific processes are driven by constraints rooted in child-specific phonetic factors. In a phonetically-based approach to phonology, if there are areas of divergence in phonetic pressures across immature and mature systems, differences across child and adult phonologies are predicted rather than problematic. The phonetically-based approach also explains the developmental elimination of child-specific processes, since in the course of typical maturation, the phonetic pressures driving these effects will cease to apply. Because children's speech-motor control capabilities are known to diverge from those of the skilled adult speaker, it is posited that articulatory factors play the dominant role in shaping child-specific phonological processes. Here it is argued that children have difficulty executing discrete movements of individual articulators, notably the tongue. By moving the tongue-jaw complex as a single unit, the child speaker can reduce the number of degrees of movement freedom and also rely on the action of the motorically simpler mandible to achieve articulatory targets.(cont.) The effects of mandibular dominance have previously been argued to play a role in shaping sound patterns in babbling and early words (MacNeilage & Davis, 1990). The preference for jaw-dominated movement can be seen to recede over time as the child establishes more reliable articulatory control. However, here evidence from the productions of older children is presented indicating that these effects continue to have an influence in later stages of development than has been previously documented. The pressure to use simultaneous movements of the tongue-jaw complex, formalized in a constraint MOVE-AS-UNIT, is argued to play a role in shaping child-specific processes including positional velar fronting, prevocalic fricative gliding, and consonant harmony. In the present approach, children's tendency to neutralize contrast in strong positions arises as MOVE-AS-UNIT interacts with asymmetries in the force and duration of articulatory gestures across different prosodic contexts. The incorporation of child-specific phonetic factors makes it possible to account for complex patterns of conditioning in child speech processes that would under other assumptions be extremely challenging to model.by Tara K. McAllister.Ph.D

Expansion of prosodic abilities at the transition from babble to words: a comparison between children with cochlear implants and normally hearing children

Objectives: This longitudinal study examined the impact of emerging vocabulary production on the ability to produce the phonetic cues to prosodic prominence in babbled and lexical disyllables of infants with Cochlear Implants (CI) and normally hearing infants (NH). Current research on typical language acquisition emphasizes the importance of vocabulary development for phonological and phonetic acquisition. Children with cochlear implants (CI) experience significant difficulties with the perception and production of prosody, and the role of possible top-down effects is therefore particularly relevant for this population. Design: Isolated disyllabic babble and first words were identified and segmented in longitudinal audio-video recordings and transcriptions for 9 NH infants and 9 infants with CI interacting with their parents. Monthly recordings were included from the onset of babbling until children had reached a cumulative vocabulary of 200 words. Three cues to prosodic prominence, F0, intensity and duration, were measured in the vocalic portions of stand-alone disyllables. In order to represent the degree of prosodic differentiation between two syllables in an utterance, the raw values for intensity and duration were transformed to ratios, and for f0 a measure of the perceptual distance in semitones was derived. The degree of prosodic differentiation for disyllabic babble and words for each cue was compared between groups. In addition, group and individual tendencies on the types of stress patterns for babble and words were also examined. Results: The CI group had overall smaller pitch and intensity distances than the NH group. For the NH group, words had greater pitch and intensity distances than babbled disyllables. Especially for pitch distance, this was accompanied by a shift towards a more clearly expressed stress pattern that reflected the influence of the ambient language. For the CI group, the same expansion in words did not take place for pitch. For intensity, the CI group gave evidence of some increase of prosodic differentiation. The results for the duration measure showed evidence of utterance-final lengthening in both groups. In words, the CI group significantly reduced durational differences between syllables so that a more even-timed, less differentiated pattern emerged. Conclusions: The onset of vocabulary production did not have the same facilitatory effect for the CI infants on the production of phonetic cues for prosody, especially for pitch. It was argued that the results for duration may reflect greater articulatory difficulties in words for the CI group than the NH group. It was suggested that the lack of clear top-down effects of the vocabulary in the CI group may be due to a lag in development caused by an initial lack of auditory stimulation, possibly compounded by the absence of auditory feedback during the babble phase

An acoustic investigation of the developmental trajectory of lexical stress contrastivity in Italian

We examined whether typically developing Italian children exhibit adult-like stress contrastivity for word productions elicited via a picture naming task (n=25 children aged 3\u20135 years and 27 adults). Stimuli were 10 trisyllabic Italian words; half began with a weak\u2013strong (WS) pattern of lexical stress across the initial 2 syllables, as in patata, while the other half began with a strong\u2013weak (SW) pattern, as in gomito. Word productions that were identified as correct via perceptual judgement were analysed acoustically. The initial 2 syllables of each correct word production were analysed in terms of the duration, peak intensity, and peak fundamental frequency of the vowels using a relative measure of contrast\u2014the normalised pairwise variability index (PVI). Results across the majority of measures showed that children\u2019s stress contrastivity was adult-like. However, the data revealed that children\u2019s contrastivity for trisyllabic words beginning with a WS pattern was not adult-like regarding the PVI for vowel duration: children showed less contrastivity than adults. This effect appeared to be driven by differences in word-medial gemination between children and adults. Results are compared with data from a recent acoustic study of stress contrastivity in English speaking children and adults and discussed in relation to language-specific and physiological motor-speech constraints on production

Early phonological acquisition by Kuwaiti Arabic children

PhD ThesisThis is the first exploration of typical phonological development in the speech of children acquiring Kuwaiti-Arabic (KA) before the age of 4;0. In many of the word’s languages, salient aspects of the ambient language have been shown to influence the child’s initial progress in language acquisition (Vihman, 1996, 2014); however, studies of phonological development of Arabic lack adequate information on the extent of the influence of factors such as frequency of occurrence of certain features and their phonological salience on the early stages of speech acquisition. A cross-sectional study design was adapted in this thesis to explore the speech of 70 typically developing children. The children were sampled from the Arabic-speaking Kuwaiti population; the children were aged 1;4 and 3;7 and gender-balanced. Spontaneous speech samples were obtained from audio and video recordings of the children while interacting with their parent for 30-minutes. The production accuracy of KA consonants was examined to explore the influence of type and token frequencies on order of consonant acquisition and the development of error patterns. The sonority index was also used to predict the order of consonant acquisition cross-linguistically. The findings were then compared with those of other dialects of Arabic to identify within-language variability and with studies on English to address cross-linguistic differences between Arabic and English early phonological development. The results are partially consistent with accounts that argue for a significant role of input frequency in determining rate and order of consonant acquisition within a language. The development of KA error patterns also shows relative sensitivity to consonant frequency. The sonority index does not always help in the prediction of all Arabic consonants, and the developmental error patterns and early word structures in Arabic and English are significantly distinct. The outcomes of this study provide essential knowledge about typical Arabic phonological development and the first step towards building a standardised phonological test for Arabic speaking children

Differences between early-developing and late-developing phonemes in phonological processing

Theoretical accounts of communication disorders often hinge on tasks with various confounds. The aim of this study was to challenge the assumption that children with specific language impairment (SLI) have deficits in phonological memory storage capacity solely because they perform poorly on nonword repetition tasks. This assumption was tested using a novel contrast of early- and late-developing phonemes that was predicted to elicit differences in nonword repetition performance even after controlling for confounding factors. Using a differential diagnosis model of testing, a variety of tasks were administered to determine if early vs. late phoneme differences (ELP) would persist after auditory perceptual, articulatory, phonological memory storage capacity, and lexical demands were minimized. In Study 1, 30 undergraduates completed nonword repetition, nonword reading, and auditory lexical decision tasks in which half of the stimuli contained only early-developing phonemes and half contained only later-developing phonemes. In Study 2, the ELP contrast was examined in another group of 20 undergraduates who completed auditory and visual lexical decision with and without concurrent articulation. Both nonword accuracy and word-nonword discriminability were consistently lower for items with later-developing phonemes than for those with early-developing phonemes, but there were no differences in response times. Results support the growing literature suggesting that nonword repetition relies on multiple processes and cannot be used as a measure of phonological memory storage capacity alone. Additionally, nonword repetition performance draws on skills apart from auditory perceptual demands, articulatory demands, and lexical knowledge. This in turn challenges the assumption that children with SLI have deficits in phonological memory storage capacity simply because they perform poorly on nonword repetition. The results may suggest that the ELP contrast reflects differences in the quality of the phonological representations that derive from the timing of phoneme acquisition, though other possible explanations for the differences are discussed (e.g., other articulatory influences). The ELP manipulation within this battery of tasks affords many possible outcomes that might adjudicate between the possible accounts of deficits that have been associated with SLI, such as perceptual and motor speech deficits that may each contribute independently or additively to poor performance in phonological processing

The Imitation of Ecuadorian Assibilated Rhotics by Naïve Andalusian Speakers from Seville

The purpose of the present thesis is to establish whether Flege’s “equivalence classification” (Flege, 1995, p. 239) operates in the same way in auditory imitation of an unfamiliar dialect as it does in second language (L2) acquisition of speech. In order to do so, this study investigates how Andalusian Spanish speakers imitate assibilated rhotics produced in Ecuadorian Spanish. Despite substantial growth in interest in D2 phonological acquisition in later years (e.g., Babel, 2009; Nielsen, 2011), little research has been done to determine whether the mechanisms that underlie the production of L2 are also responsible for the auditory imitation of an unfamiliar dialect. Ecuadorian Spanish is characterized by assibilated and fricative rhotics (e.g., Lipski, 1994), whereas trills and taps are the main rhotics present in Andalusian Spanish (e.g., Blecua Falgueras, 2001). The Andalusian variety may include sibilants as allophonic variants of the affricates, as in [tʃ] → [ʃ] (e.g., Carbonero, 1982, 2001). In this study, 31 highly educated Sevillian Andalusian Spanish speakers were recorded. The participants completed imitation tasks, reading tasks, and a background questionnaire. This thesis contributes to our understanding of the mechanisms involved in early stages of auditory imitation of an unfamiliar dialect and assesses the effect of linguistic and extralinguistic factors in the production of the Ecuadorian assibilated rhotics. In all, I conclude that the similarity of the patterns found in the production of L2 and D2 suggests that equivalence classification does operate in a similar way in both cases

Audio-visual training effect on L2 perception and production of English /0/-/s/ and /d/-/z/ by Mandarin speakers

PhD ThesisResearch on L2 speech perception and production indicate that adult language learners are able to acquire L2 speech sounds that they initially have difficulty with (Best, 1994). Moreover, use of the audiovisual modality, which provides language learners with articulatory information for speech sounds, has been illustrated to be effective in L2 speech perception training (Hazan et al., 2005). Since auditory and visual skills are integrated with each other in speech perception, audiovisual perception training may enhance language learners’ auditory perception of L2 speech sounds (Bernstein, Auer Jr, Ebehardt, and Jiang, 2013). However, little research has been conducted on L1 Mandarin learners of English. Based on these hypotheses, this study investigated whether audiovisual perception training can improve learners’ auditory perception and production of L2 speech sounds. A pilot study was performed on 42 L1-Mandarin learners of English (L1-dialect: Chongqing Mandarin (CQd)) in which their perception and production of English consonants was tested. According to the results, 29 of the subjects had difficulty in the perception and production of /θ/-/s/ and /ð/-/z/. Therefore, these 29 subjects were selected as the experimental group to attend a 9-session audiovisual perception training programme, in which identification tasks for the minimal pairs /θ/-/s/ and /ð/-/z/ were conducted. The subjects’ perception and production performance was tested before, during and at the end of the training with an AXB task and “read aloud” task. In view of the threat to interval validity arising from a repeated testing effect, a control group was tested with the same AXB task and intervals as that of the experimental group. The results show that the experimental group’s perception and production accuracy improved substantially during and by the end of the training programme. Indeed, whilst the control group also showed perception improvement across the pre-test and post-test, their degree of improvement was significantly lower than that of the experimental group. These results therefore confirm the value of the audiovisual modality in L2 speech perception training

A Study of the Relationship of Certain Variables to Sex Characteristic Identification From the Speech of Heterosexual and Homosexual Individuals.

This study explored relationships of speaker sex and masculinity-femininity judgments and 12 measures of rate, fundamental frequency, and intensity from taped reading and spontaneous speech samples of female and male heterosexual and homosexual individuals. Phase One was designed to determine judgment reliability and any procedural variables that might influence judgments. Sex judgments were more accurate on the speakers\u27 second performances. Both sex and masculine-feminine judgments were more accurate on reading than on spontaneous speech. Analysis of judgments from type-scripts of spontaneous speech yielded a significant judge sex-by-training interaction. In Phase Two, 20 listeners judged sex and masculinity-femininity from taped reading and spontaneous speech samples of female and male heterosexual and homosexual speakers. The mean fundamental frequency low of females judged male/undecided was higher than those judged correctly. The mean intensity standard deviation of females judged female intensity standard deviation of female judged female was greater than that of females judged male/undecided. All male speakers were correctly identified. Females judged masculine displayed a greater mean number of syllables per second, a lower mean fundamental frequency high, and a more restricted mean fundamental frequency range than those correctly described. Males judged feminine displayed a higher mean fundamental frequency mode and a greater mean intensity standard deviation than those correctly described. Female speakers were judged male more often than males were judged female. Homosexuals were incorrectly described as masculine or feminine more often than heterosexuals. Males averaged more syllables per second than females. Mean fundamental frequency low, high, and mode were higher for females and males. Mean fundamental frequency range was greater for females. Mean intensity low and mean intensity range were significantly different for heterosexuals and homosexuals. Significant sex-by-type interaction occurred on mean intensity range and on mean syllables per second. Mean syllables per second, words per minute, percent pause time, fundamental frequency range, and intensity standard deviation were significantly different for reading and spontaneous speech. Suggestions for clinical application and future research were made