Daniel Williams

Dr. Daniel Williams

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Research Focus & Metrics

Academic Career Length

16Years (2011-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 November 2014 in The Journal of the Acoustical Society of America
Verified
Journal Article
Closed access
DWDaniel Williams
Daniel Williams
PEPaola Escudero
Paola Escudero
This study compares the duration and first two formants (F1 and F2) of 11 nominal monophthongs and five nominal diphthongs in Standard Southern British English (SSBE) and a Northern English dialect. F1 and F2 trajectories were fitted with parametric curves using the discrete cosine transform (DCT) and the zeroth DCT coefficient represented formant trajectory means and the first DCT coefficient represented the magnitude and direction of formant trajectory change to characterize vowel inherent spectral change (VISC). Cross-dialectal comparisons involving these measures revealed significant differences for the phonologically back monophthongs /ɒ, ɔː, ʊ, uː/ and also /зː/ and the diphthongs /eɪ, əʊ, aɪ, ɔɪ/. Most cross-dialectal differences are in zeroth DCT coefficients, suggesting formant trajectory means tend to characterize such differences, while first DCT coefficient differences were more numerous for diphthongs. With respect to VISC, the most striking differences are that /uː/ is considerably more diphthongized in the Northern dialect and that the F2 trajectory of /əʊ/ proceeds in opposite directions in the two dialects. Cross-dialectal differences were found to be largely unaffected by the consonantal context in which the vowels were produced. The implications of the results are discussed in relation to VISC, consonantal context effects and speech perception.

1 July 2016 in The Journal of the Acoustical Society of America
Verified
Journal Article
Closed access
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JEJaydene Elvin
Jaydene Elvin
DWDaniel Williams
Daniel Williams
PEPaola Escudero
Paola Escudero
This study provides a thorough acoustic analysis of the 18 Australian English monophthongs and diphthongs produced in a variety of phonetic contexts by young adult speakers from Western Sydney. The 18 vowels are well separated by duration and dynamic formant trajectory information. Vowel durations and formant trajectories were affected by the consonantal context in which the vowels were produced, particularly those produced in the /hVd/ context. Finally, the results indicate that capturing aspects of vowel inherent spectral change may be useful in future cross-dialectal and cross-linguistic studies.

1 November 2014 in Cognition
Verified
Journal Article
Closed access
PEPaola Escudero
Paola Escudero
DWDaniel Williams
Daniel Williams

18 April 2012 in The Journal of the Acoustical Society of America
Verified
Journal Article
Closed access
PEPaola Escudero
Paola Escudero
DWDaniel Williams
Daniel Williams
Peruvian Spanish (PS) and Iberian Spanish (IS) learners were tested on their ability to categorically discriminate and identify Dutch vowels. It was predicted that the acoustic differences between the vowel productions of the two dialects, which compare differently to Dutch vowels, would manifest in differential L2 perception for listeners of these two dialects. The results show that although PS learners had higher general L2 proficiency, IS learners were more accurate at discriminating all five contrasts and at identifying six of the L2 Dutch vowels. These findings confirm that acoustic differences in native vowel production lead to differential L2 vowel perception.

11 January 2011 in The Journal of the Acoustical Society of America
Verified
Journal Article
Closed access
PEPaola Escudero
Paola Escudero
DWDaniel Williams
Daniel Williams
Many cross-language and L2 speech perception studies have been conducted on English sounds and a limited number of speakers or synthetic tokens have been used for auditory stimuli. The Spanish listeners of the present study were presented with natural tokens of Dutch vowels produced by males and females selected from the corpus reported in Adank [(2004) J. Acoust. Soc. Am.116, 1729–1738]. The results show that single category assimilations are common and that certain Dutch vowels frequently assimilate to Spanish diphthongs. Predictions are made for Spanish learners’ initial stage in the acquisition of the Dutch vowel system.

26 November 2015 in International Journal of Bilingualism
Verified
Journal Article
Closed access
Robert MayrRobert Mayr
Robert Mayr
Jonathan MorrisJonathan Morris
Jonathan Morris
Ineke MennenIneke Mennen
Ineke Mennen
DWDaniel Williams
Daniel Williams
Aims and objectives: This study investigates the effects of individual bilingualism and long-term language contact on monophthongal vowel productions in English and Welsh. Design: To this end, we recorded the Welsh and English vowel productions of two sets of Welsh-English bilinguals differing in home language use, as well as the English vowel productions of English monolinguals. Data and analysis: The data were analysed acoustically, with a focus on spectral and temporal properties. Comparisons were then made within each language and cross-linguistically. Findings: The results of a cross-linguistic acoustic comparison revealed a high degree of convergence in the monophthong systems of Welsh and English, but also some language-specific categories. Interestingly, at the individual level we found no effect of linguistic experience on vowel production: the two sets of bilinguals and the English monolinguals did not differ in their realisation of English vowels, and the two sets of bilinguals did not differ in their realisation of Welsh vowels. Originality: This is one of few studies to examine the effect of linguistic background on variation in Welsh and English bilingual speech, and the first to compare the speech of Welsh-English bilinguals and English monolinguals. More specifically, it investigates the extent to which a speaker’s home language can affect phonetic variation in a close-knit community of speakers and in a situation characterised by long-term language contact. Implications: The findings demonstrate pervasive phonetic convergence in a language contact situation with a historical substrate. They also indicate that a homogeneous peer group with shared values can override the effects of individual linguistic experience.