Anne Fabricius, Roskilde University Dominic Watt, University of York and J.P French Associates

 Background to the paper  Aim of the research  Introducing the S-centroid anchor method  Application to some vowel data from British English (SSBE/Modern RP)  Discussion and further implications 2Angle configurations and the S-centroid

 Quantitative methods in a quantitative discipline  The art and science of vowel change (Labov 1994)  Earlier work this study is based on  Watt and Fabricius S-centroid method (Watt and Fabricius 2002)  TRAP/STRUT rotation in RP (Fabricius 2007) and angle methods using vowel juxtapositions  Testing normalisation methods (Fabricius, Watt and Johnson 2009) for geometrically-related properties  Here: Combining the two (normalization and modelling changing vowel loci distributions around the centroid) 3Angle configurations and the S-centroid

Adapted from Fabricius 2007: 300 4Angle configurations and the S-centroid

Flynn 2010: slide 16 For variety-specific modifications of the Watt and Fabricius S-centroid method, see also Durian, forthcoming and Bigham mW&F uses F1 of [a] only 5Angle configurations and the S-centroid

 In geometry, the centroid, geometric center, or barycenter of a plane figure or two-dimensional shape X is the intersection of all straight lines that divide X into two parts of equal moment about the line. Informally, it is the "average" (arithmetic mean) of all points of X.  (From Wikipedia) 6Angle configurations and the S-centroid

 Peeters Angle configurations and the S-centroid

 To present the method  To investigate the methodological advantages for sociophonetics of representing relative planar locations as vectors vis à vis a pre-defined geometrical centroid of the vowel space  To ask whether this supports other arguments in favour of a centroid-based normalisation method? (in the spirit of Fabricius, Watt and Johnson 2009) 8Angle configurations and the S-centroid

 Make no claims here about the centroid’s perceptual significance (although the concept does feature in some perception/normalisation research, eg Deterding 1990)  Used here as a geometric point to investigate and illustrate properties of vowel distributions in F1/F2 space 9Angle configurations and the S-centroid

 Effect of speech disorders on the vowel space and distance of vowels from the centroid (e.g. in stuttering: Blomgren, Robb and Chen 1998)  Pickering 1986 formalised peripherality measured as dispersion from a centroid, context speech perception research  Hyper- and hypo-articulation, ie clear and indistinct speech: (Lindblom 1990, 1996, Ferguson & Kewley- Port, 2002; Picheny, Durlach, & Braida, 1986)  Whiteside 2001; NB definition of centroid used here differs from this presentation since axes are derived differently (using Bark differences) 10Angle configurations and the S-centroid

 R-algorithm developed by Daniel Ezra Johnson after an idea by Anne Fabricius  Available here (The Modern RP Page) 11Angle configurations and the S-centroid

0°0° 180° -180° 90° -90° S-centroid point F1 F2 12Angle configurations and the S-centroid

0°0° 180° -180° 90° -90° S-centroid point F1 F2 i u a 13Angle configurations and the S-centroid

14Angle configurations and the S-centroid

 Documenting changes by measurements in degrees vis a vis a stable point, rather than eyeball judgments of relative placement  Could also be used in combination with Euclidean/Cartesian distances (as in Fabricius 2007, Richards, Haddican and Foulkes 2009)  Quantification enables further statistical testing  Has potential applications in determining the nature of centre versus periphery in the vowel space (Labov 1994) in a more reproducible way 15Angle configurations and the S-centroid

 RP generational vowel data from Hawkins and Midgley 2005 and Moreiras 2006, plus Fabricius 2009  using R script devised by Daniel Ezra Johnson  This example: short vowel system with lines connecting average vowel loci 16Angle configurations and the S-centroid

17 Female speakers, 1998 cohort Angle configurations and the S-centroid (Data from Fabricius 2009)

18 Female speakers, 2008 cohort Angle configurations and the S-centroid (Data from Fabricius 2009)

19 Male speakers, 1998 cohort (Data from Fabricius 2009) Angle configurations and the S-centroid

20 Male speakers, 2008 cohort (Data from Fabricius 2009) Angle configurations and the S-centroid

 To make these types of configurations more easily comparable  By using the S-centroid point as anchor  deriving angles vis-à-vis the centroid point  The S-centroid point is common to ALL speakers in the sample since they are all normalised using the W&F (or mW&F) method  Advantage: the S-centroid does not move over time Angle configurations and the S-centroid21

Angle configurations and the S-centroid22 Illustration

Angle configurations and the S-centroid23 FLEECE stable over time: OM, OF: older generation; YM, YF: younger generation

0°0° 180° -180° 90° -90° S-centroid point F1 F2 24Angle configurations and the S-centroid FLEECE

Angle configurations and the S-centroid25 FOOT moving over time

0°0° 180° -180° 90° -90° S-centroid point F1 F2 26Angle configurations and the S-centroid FOOT, older FOOT, YF3

Angle configurations and the S-centroid27 LOT variability, mostly among younger female speakers

Angle configurations and the S-centroid28 STRUT in this perspective also variable; nb Reduced scale here

 What are the methodological advantages to representing relative planar locations as vectors vis a vis the centroid location of the vowel space?  Quantifiability, reproducibility, visual evidence backing auditory perceptions  Does this argue for the advantages of a centroid-point based normalisation method?  Yes, and the method could also be adapted to work from the centroid-based Lobanov normalisation algorithm.  But Lobanov’s normalisation method is in some cases too powerful (close to a standard statistical normalisation technique) and performs less well overall (in several testing parameters) than mW&F in Flynn’s comparison of 20 normalisation algorithms (Flynn 2010) 29Angle configurations and the S-centroid

 Method offered here as an aid to the sociophonetic community  The illustrative chart template will also be available online ( MS Excel.crtx file)  NB A Euclidean distance metric could be included as well  R-code will be available and can be adjusted 30Angle configurations and the S-centroid

 Bigham, Douglas Dialect contact and accommodation among emerging adults in a university setting. Ph.D. thesis. The University of Texas at Austin.  Deterding, David Speaker Normalisation for Automatic Speech Recognition, Unpublished PhD Thesis, Cambridge University.  Fabricius, Anne Variation and change in the TRAP and STRUT vowels of RP: a real time comparison of five acoustic data sets. JIPA 37:3:  Fabricius, Anne Short vowels in real time: TRAP, STRUT and FOOT in the South of England. Paper presented at ICLaVE 5, Copenhagen. June 27 th ( )  Fabricius, Anne H., Dominic Watt and Daniel Ezra Johnson A comparison of three speaker-intrinsic vowel formant frequency normalization algorithms for sociophonetics. Language Variation and Change, 21,3:1-23.  Flynn, Nicholas Comparing vowel formant normalisation procedures. Talk given at York Postgraduate Mini-conference, June 10th,  Hawkins, Sarah and Jonathan Midgley Formant frequencies of RP monophthongs in four age groups of speakers. JIPA 30:  Labov, William Principles of Linguistic Change volume 1: Internal Factors. Oxford: Blackwell. 31Angle configurations and the S-centroid

 Lindblom, B. 1990: Explaining phonetic variation: A sketch of the H&H theory, in Speech Production and Speech Modeling, edited by W. J. Hardcastle and A. Marchal. Kluwer Academic, Netherlands, pp. 403–439.  Lindblom, B. 1996: Role of articulation in speech perception: Clues from production. Journal of the Acoustical Society of America, 99, 1683–1692.  Moreiras, C An acoustic study of vowel change in female adult speakers of RP. Unpublished undergraduate dissertation, University College London.  Peeters, Geoffroy A large set of audio features for sound description (similarity and classification) in the CUIDADO project. synthese/peeters/ARTICLES/Peeters_2003_cuidadoaudiofeatures.pdf synthese/peeters/ARTICLES/Peeters_2003_cuidadoaudiofeatures.pdf  Pickering, J.B Auditory vowel formant variability. Unpublished doctoral dissertation, Oxford University.  Richards, Hazel, Bill Haddican and Paul Foulkes Exhibiting standards in the FACE of dialect levelling. Paper presented at ICLaVE 5, Copenhagen, June  Watt, Dominic and Anne Fabricius Evaluation of a technique for improving the mapping of multiple speakers’ vowel spaces in the F1-F2 plane. Leeds Working papers in Linguistics and Phonetics. 9: Angle configurations and the S-centroid32

 Daniel Ezra Johnson  Tyler Kendall  Nicholas Flynn  Nicolai Pharao Angle configurations and the S-centroid33