PowerPoint Presentation
James M ScobbieCASL Research Centre
LOT summer schoolUltrasound, phonetics, phonology: Articulation
for Beginners!With special thanks to collaboratorsJane Stuart-Smith
& Eleanor LawsonJoanne Cleland & Zoe RoxburghNatasha
Zharkova, Laura Black, Steve CowenReenu Punnoose, Koen
SebreghtsSonja Schaeffler & Ineke MennenConny HeydeAlan Wrench
(aka Articulate Instruments Ltd) for AAA software and UTI hardware
Various funding thank you to ESRC, EPSRC, QMU
June 2013Sociophonetics / Lg var & changeScottish
EnglishDerhoticisation among WC speakers Rhotic tongue shapeIs it
time for some nitty gritty stuff?Scottish English againFronted
/u/Extensions, if timeNorthern Irish /u/ and diphthongs
Tick these off as I go2MRI [o]
MRI [i]
MRI [y]
SSE /o/
What about real vowels?
UTI single speaker for comparisonExample of a UTI vowel space,
un-rotated
Front!Front?Probably Zoe8What about articulation?Compare
frontness in F2 & frontness in mmheight in F1 & height in
mmWhat are articulatory frontness and height?
Whole tongue shape?Constriction degree / cross-sectional area /
tube diameter?High point of the tongue surface? Daniel Jones
(1917)
Experimental phonetics and its utility to the linguist. Nature
100: 96-98.Some examples of something easyVowels/u/ in relation to
/i/ in terms of frontness/u/s similarity to /i/ in tongue shapeEasy
questions are still worth asking!
Analysing minimal data setsA socially-stratified corpus (ECB08)
was collected to examine social variation in post-vocalic /r/
articulation WC vs. MC teenagersFor context, each speaker produced
just one (real word) token of each vowel phonemeLabial consonants
avoid lingual coarticulation9 monophthongal vowel phonemes 3
diphthongs /ai/, /au/, /oi/ were not elicitedSingle word citation
forms, no carrier phraseOne time point was analysed artic
target
What can we get out of this?Video UTI, so only ~30fpsAveraging
acoustics is also hardMale and female speakersAdolescent speakers
of variable vocal tract lengthNo opportunity for complex
normalisation
How front is Scottish /u/?hembeamfamehipmapboomhumawehopeWC n=8,
MC n=7 1 token each
Front!Formants and frontnessFormants are vocal tract resonancesA
standard approach for 60 years has been to measure F1 & F2Low
F1 = height & High F2 = frontnessWe will come back to these
metaphors laterNothing is as simple as this metaphor implies, when
you get down to detailHigher formants are also importantOther
factors affect these formantsBut they are easy to measure, and plot
well
SSBE for comparisonHawkins and Midgely, cf Wells, Deterding
Front!Acoustic analysisCalculate the F2 distance (Bark) from
/i/, the vowel with the highest F2To /o/, /u/ and /e/ for each
speakerRepeat for a normalised set by treating the /i/-/o/ distance
as 100% (corner vowel to corner vowel), which will make comparison
to articulation easierCalculate the distance (Bark) from /i/To /u/
and /e/ (and /o/) for each speakerIt was hard to measure F1 for
/a/, so no normalisation
Acoustic analysis/u/ is acoustically non-backRelative to each
speakers /i/ (& /o/),/u/ is Mid F2 (Hz) Mid-high F2 (Bark)61%
front (from /o/)/e/ has high F294% front2 speakers have/u/ < 50%
front (just)
Front!17This is all speakers, each done individually, i.e.
normalised to /i/ in a linear way.Acoustic analysis/u/ and /e/ are
significantly non-high /u/ not significantly different to /e/ or
/o/ in F1In 5/14 speakers, /u/ had a higher rel F1 than /e/Hz /
Bark are almost identical at these frequencies
18This is all speakers, each done individually, i.e. normalised
to /i/ in a linear way./u/ acoustic summary/u/ has a raised F22.6
Bark lower than /i/4.1 Bark higher than /o//u/ has a raised F10.6
Bark higher than /i/Non-distinct from the raised F1 of /e/, 0.4
BarkWith UTIWe only have mid-sagittal tongue curvesNot passive
articulators (vocal tract tube)Not all the tongue surfaceNot all
the internal tongue tissueNot lips (well, not for this data set)One
token per speaker (for this data set)But unlike EMAWe are not
limited to 3 or 4 anterior pointsAnd unlike MRIUTI is cheap,
non-invasive, portable and quickWe can collect & trace 12
tokens of 5V in half a day
UTI consistently shows Scottish /u/ is lower and
centralised/fronted compared to other vowelsFront!Vowel space
(typical WC)21LM17
Front!Vowel space (typical MC)EF422High point of tongueWhats
horizontal about a curving vocal tract?Whats the orientation of the
probe to the head?Images can be rotated by you, looking, for
qualitative understanding, if there is a fixed aspect ratio on x/y
axesImages can be rotated for quantitative analysis of horizontal
and vertical by the analystOcclusal plane is replicable and
standard and provides a reasonable horizontal for the anterior
portion of the vocal tract
common /o i/ tangentAssumed occlusal
ECB08 didnt collect occlusal biteplanesDifferent shape hard
palates dont helpTwo approaches to estimating horizontal rather
than adopting the basic axes of the probeECB08 Soc-Lx sample
Articulatory analysis
/u/ is fronter in articulatory space than acoustics
/u/ is either more front than central, or fully front99.6%,