@article{KashimaWilliamsEllisonetal.2016,
  author    = {Kashima, Eri and Williams, Daniel and Ellison, T. Mark and Schokkin, Dineke and Escudero, Paola},
  title     = {Uncovering the acoustic vowel space of a previously undescribed language: The vowels of Nambo},
  series = {The journal of the Acoustical Society of America},
  volume    = {139},
  journal   = {The journal of the Acoustical Society of America},
  publisher = {American Institute of Physics},
  address   = {Melville},
  issn      = {0001-4966},
  doi       = {10.1121/1.4954395},
  pages     = {EL252 -- EL256},
  year      = {2016},
  abstract  = {This study presents the first acoustic description of the vowel space of a Papuan language—Nambo, spoken in southern Papua New Guinea—based on duration and first and second formant measurements from 19 adult male and female speakers across three age groups (young, middle-aged, senior). Phonemically, Nambo has six full vowels /i, e, {\ae}, \&\#593;, o, u/ and a reduced vowel tentatively labeled /\&\#601;/. Unlike the full vowels, the quality of /\&\#601;/ showed great variation: seniors' and young females' realizations tended to be more open and retracted than those by young males, while middle-aged speakers' productions fell between these two variants.},
  language  = {en}
}
@article{WilliamsEscuderoGafos2018,
  author    = {Williams, Daniel Philip and Escudero, Paola and Gafos, Adamantios I.},
  title     = {Spectral change and duration as cues in Australian English listeners' front vowel categorization},
  series = {The journal of the Acoustical Society of America},
  volume    = {144},
  journal   = {The journal of the Acoustical Society of America},
  number    = {3},
  publisher = {American Institute of Physics},
  address   = {Melville},
  issn      = {0001-4966},
  doi       = {10.1121/1.5055019},
  pages     = {EL215 -- EL221},
  year      = {2018},
  abstract  = {Australian English /iː/, /ɪ/, and /ɪə/ exhibit almost identical average first (F1) and second (F2) formant frequencies and differ in duration and vowel inherent spectral change (VISC). The cues of duration, F1 × F2 trajectory direction (TD) and trajectory length (TL) were assessed in listeners' categorization of /iː/ and /ɪə/ compared to /ɪ/. Duration was important for distinguishing both /iː/ and /ɪə/ from /ɪ/. TD and TL were important for categorizing /iː/ versus /ɪ/, whereas only TL was important for /ɪə/ versus /ɪ/. Finally, listeners' use of duration and VISC was not mutually affected for either vowel compared to /ɪ/.},
  language  = {en}
}
@misc{WilliamsEscuderoGafos2018,
  author    = {Williams, Daniel and Escudero, Paola and Gafos, Adamantios I.},
  title     = {Perceptual sensitivity to spectral change in Australian English close front vowels},
  series = {19 th annual conference of the international speech communicaton association (INTERSPEECH 2018), VOLS 1-6: Speech research for emerging marjets in multilingual societies},
  journal   = {19 th annual conference of the international speech communicaton association (INTERSPEECH 2018), VOLS 1-6: Speech research for emerging marjets in multilingual societies},
  publisher = {ISCA-International Speech Communication Association},
  address   = {Baixas},
  isbn      = {978-1-5108-7221-9},
  issn      = {2308-457X},
  doi       = {10.21437/Interspeech.2018-2505},
  pages     = {1442 -- 1446},
  year      = {2018},
  abstract  = {Speech scientists have long noted that the qualities of naturally-produced vowels do not remain constant over their durations regardless of being nominally "monophthongs" or "diphthongs". Recent acoustic corpora show that there are consistent patterns of first (F1) and second (F2) formant frequency change across different vowel categories. The three Australian English (AusE) close front vowels /i:, 1, i/ provide a striking example: while their midpoint or mean F1 and F2 frequencies are virtually identical, their spectral change patterns distinctly differ. The results indicate that, despite the distinct patterns of spectral change of AusE /i:, i, la/ in production, its perceptual relevance is not uniform, but rather vowel-category dependent.},
  language  = {en}
}
@article{WilliamsEscudero2014,
  author    = {Williams, Daniel and Escudero, Paola},
  title     = {Influences of listeners' native and other dialects on cross-language vowel perception},
  series = {Frontiers in psychology},
  volume    = {5},
  journal   = {Frontiers in psychology},
  publisher = {Frontiers Research Foundation},
  address   = {Lausanne},
  issn      = {1664-1078},
  doi       = {10.3389/fpsyg.2014.01065},
  pages     = {10},
  year      = {2014},
  language  = {en}
}
@article{ElvinWilliamsEscudero2016,
  author    = {Elvin, Jaydene and Williams, Daniel and Escudero, Paola},
  title     = {Dynamic acoustic properties of monophthongs and diphthongs in Western Sydney Australian English},
  series = {The journal of the Acoustical Society of America},
  volume    = {140},
  journal   = {The journal of the Acoustical Society of America},
  publisher = {American Institute of Physics},
  address   = {Melville},
  issn      = {0001-4966},
  doi       = {10.1121/1.4952387},
  pages     = {576 -- 581},
  year      = {2016},
  abstract  = {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. (C) 2016 Acoustical Society of America.},
  language  = {en}
}
@article{WilliamsEscudero2014,
  author    = {Williams, Daniel and Escudero, Paola},
  title     = {A cross-dialectal acoustic comparison of vowels in Northern and Southern British English},
  series = {The journal of the Acoustical Society of America},
  volume    = {136},
  journal   = {The journal of the Acoustical Society of America},
  number    = {5},
  publisher = {American Institute of Physics},
  address   = {Melville},
  issn      = {0001-4966},
  doi       = {10.1121/1.4896471},
  pages     = {2751 -- 2761},
  year      = {2014},
  abstract  = {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 /D, , , u:/ and also /3z:/ and the diphthongs /eI, e, aI, I/. 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 /u:/is considerably more diphthongized in the Northern dialect and that the F2 trajectory of /e/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. (c) 2014 Acoustical Society of America.},
  language  = {en}
}