CASL
Permanent URI for this collectionhttps://eresearch.qmu.ac.uk/handle/20.500.12289/22
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Item Standard English in Edinburgh and Glasgow: the Scottish vowel length rule revealed.(Arnold, 1999) Scobbie, James M.; Hewlett, Nigel; Turk, Alice E.Item An ultrasound study of lingual coarticulation in /sV/ syllables produced by adults and typically developing children(Cambridge University Press, 2012-08-02) Zharkova, Natalia; Hewlett, Nigel; Hardcastle, William J.; Economic and Social Research CouncilAccording to the Degree of Articulatory Constraint model of lingual coarticulation, the consonant /s/ has some scope for tongue adaptation to neighbouring vowels, since the tongue dorsum is not directly involved in constriction formation for this consonant. The present study aimed to establish whether the tongue shape for /s/ in consonant-vowel syllables was influenced by the nature of the following vowel, in Scottish-English-speaking children and adults. Ultrasound tongue imaging was used to establish the presence or otherwise of a vowel effect at the consonant midpoint, by measuring differences between the consonant tongue contours in different vowel environments. In adults, the vowel pairs /a/-/i/, /a/-/u/ and /i/-/u/ exerted significant coarticulatory effects on /s/. In children, no significant effects on /s/ were observed. Greater within-speaker variability in lingual articulation was found in children than in adults. The reduced ability of children to anticipate the tongue configuration of a following vowel whilst simultaneously implementing an initial /s/ sound could be explained by lesser differential control of tip/blade and tongue body.Item Measuring lingual coarticulation from midsagittal tongue contours: Description and example calculations using English /t/ and //(2009-04) Zharkova, Natalia; Hewlett, NigelThe purpose of this study was to test the feasibility of a protocol for measuring coarticulation using tongue surface outline data derived from ultrasound imaging. Ultrasound and acoustic data were collected from three speakers of Southern British English while they repeated a list of three sentences 15 times. Tongue surface outlines for the consonant /t/ in /a{script}ta{script}/ (in ...Ma tasked...) were compared with those for the /t/ in /iti/ (in ... Leigh teased...) and tongue surface outlines for the vowel /a{script}/ in /a{script}ka{script}/ (in ... Ma cast...) were compared with those in /a{script}ta{script}/. Nearest neighbour distance calculations were used for the comparison of tongue surface outlines. Mean distance in midsagittal tongue surface outline between tokens of the same phoneme across two different environments was taken as a measure of the phoneme's susceptibility to environmental influence. The calculations show that the tongue contour during /t/ adapts to the influence of the neighbouring vowels approximately three times more than the tongue contour during /a{script}/ adapts to the influence of the neighbouring consonants. The applicability of the measure proposed in this paper to future speech research using ultrasound and other articulatory techniques is discussed. 2008 Elsevier Ltd. All rights reserved.Item Perceptual Strategies in Phonological Disorder: Assessment, Remediation and Evaluation(1998) Watson, Jocelynne; Hewlett, NigelEvidence is presented that immature perceptual strategies are a contributory factor to developmental phonological disorder. The findings endorse the current re-focusing of attention on the role of perception in disordered speech and language acquisition and also highlight the need for more precise assessment and remediation techniques. Technical developments working towards providing these are reviewed and implications for future clinical practice discussed.Item An ultrasound study of lingual coarticulation in children and adults(2008-12) Zharkova, Natalia; Hewlett, Nigel; Hardcastle, William J.There have been a number of studies which compared coarticulatory patterns in children and adults, but these studies have produced conflicting results, particularly with respect to anticipatory lingual coarticulation. This study used articulatory measures derived from ultrasound imaging, in order to establish any differences between child and adult coarticulatory patterns, and to quantify the degree of variability in children's and adults' productions. The participants were four adults and four normally developing children aged 6 to 9 years, all speakers of Standard Scottish English. The data were the syllables /i/, /u/ and /a/, in the carrier phrase It's a -_ Pam- (ten repetitions). Synchronised ultrasound and acoustic data were recorded using the Queen Margaret University ultrasound system. Extent of consonantal coarticulation and within-speaker variation in child and adult productions were compared according to a new ultrasound-based measure of coarticulation. A significantly greater amount of anticipatory lingual coarticulation was found in children than in adults. Much within-group variability was observed, in both age groups. Within-speaker variability was significantly greater in children than in adults. These results are in agreement with some previous studies. Possible reasons are discussed for some of the contradictions in the literature on child and adult coarticulation.Item Coarticulation as an indicator of speech motor control development in children: An ultrasound study(2011-01) Zharkova, Natalia; Hewlett, Nigel; Hardcastle, William J.There are still crucial gaps in our knowledge about developmental paths taken by children to adult-like speech motor control. Mature control of articulators during speaking is manifested in the appropriate extent of coarticulation (the articulatory overlap of speech sounds). This study compared lingual coarticulatory properties of child and adult speech, using ultrasound tongue imaging. The participants were speakers of Standard Scottish English, ten adults and ten children aged 6-9 years. Consonant-vowel syllables were presented in a carrier phrase. Distances between tongue curves were used to quantify coarticulation. In both adults and children, vowel pairs /a/-/i/ and /a/-/u/ significantly affected the consonant, and the vowel pair /i/-/u/ did not. Extent of coarticulation was significantly greater in the children than in the adults, providing support for the notion that children's speech production operates with larger units than adults'. More within-speaker variability was found in the children than in the adults. 2011 Human Kinetics, Inc.Item An introduction to the science of phonetics.(Lawrence Erlbaum Associates, 2006) Hewlett, Nigel; Beck, Janet M.Item Analysing coarticulation in Scottish English children and adults : an ultrasound study(Canadian Acoustical Association, 2008) Zharkova, Natalia; Hewlett, Nigel; Hardcastle, William J.One of the gaps in our knowledge about developmental paths taken by children to adult-like motor control of speech concerns the development of coarticulation.Item Lingual Coarticulation in Preadolescents and Adults: An Ultrasound Study. ESRC End of Award Report, RES-000-22-4075(ESRC, 2012) Zharkova, Natalia; Hewlett, Nigel; Lickley, RobinWhen people combine sounds to make words, there is overlap in the tongue movements involved in articulating individual sounds, referred to as lingual coarticulation. For example, in adult speech, tongue positions at mid-consonant, in the words she- and shah-, differ because of the influence of the following vowel. The research team's earlier work showed that young children differed from adults in the extent of vowel-on-consonant coarticulation. In this project, for the first time, a quantitative analysis of the dynamics of tongue movements was performed. The project used high-speed ultrasound to measure lingual coarticulation in the syllables she-, shah-, sea- and 'Sah', comparing preadolescent children and adults, fifteen speakers in each age group. In both age groups and both consonants, the tongue position at mid-consonant was affected by the identity of the following vowel. There was no significant effect of age on the size of the vowel-related difference in tongue posture, nor on within-speaker variability in tongue placement. Age-related differences were observed in the onset of coarticulation. While in the adults, the vowel effect was present throughout the consonant for both consonants, in preadolescents the effect was apparent later into the first half of the consonant. The results of the study suggest a near-adult-like achievement in the development of lingual control by preadolescents, with respect to the coarticulation of fricative-vowel sequences. However age-related differences in timing may indicate that preadolescents have still to gain the extent of forward planning in speech production which is possible for a typical adult.Item An ultrasound study of lingual coarticulation in children and adults: Full Research Report ESRC End of Award Report, RES-000-22-2833(ESRC, 2009) Zharkova, Natalia; Hewlett, Nigel; Hardcastle, William J.The aims of this project were to establish how children's patterns of coarticulation differ from adults', and to attempt to explain the observed coarticulatory patterns, as well as the nature and the degree of variability found in children and adults.
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