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Slide 2 James M Scobbie CASL Research Centre LOT summer school Ultrasound, phonetics, phonology: Articulation for Beginners! With special thanks to collaborators Jane Stuart-Smith & Eleanor Lawson Joanne Cleland & Zoe Roxburgh Natasha Zharkova, Laura Black, Steve Cowen Reenu Punnoose, Koen Sebreghts Sonja Schaeffler & Ineke Mennen Conny Heyde Alan Wrench (aka Articulate Instruments Ltd) for AAA software and UTI hardware Various funding thank you to ESRC, EPSRC, QMU June 2013 Slide 3 Sociophonetics / Lg var & change Scottish English Derhoticisation among WC speakers Rhotic tongue shape Is it time for some nitty gritty stuff? Scottish English again Fronted /u/ Extensions, if time Northern Irish /u/ and diphthongs Slide 4 MRI [o] Slide 5 MRI [i] Slide 6 MRI [y] Slide 7 SSE /o/ Slide 8 What about real vowels? Slide 9 UTI single speaker for comparison Example of a UTI vowel space, un-rotated Front! Front? Slide 10 What about articulation? Compare frontness in F2 & frontness in mm height in F1 & height in mm What 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. Slide 11 Some examples of something easy Vowels /u/ in relation to /i/ in terms of frontness /u/s similarity to /i/ in tongue shape Easy questions are still worth asking! Slide 12 Analysing minimal data sets A socially-stratified corpus (ECB08) was collected to examine social variation in post- vocalic /r/ articulation WC vs. MC teenagers For context, each speaker produced just one (real word) token of each vowel phoneme Labial consonants avoid lingual coarticulation 9 monophthongal vowel phonemes 3 diphthongs /ai/, /au/, /oi/ were not elicited Single word citation forms, no carrier phrase One time point was analysed artic target Slide 13 What can we get out of this? Video UTI, so only ~30fps Averaging acoustics is also hard Male and female speakers Adolescent speakers of variable vocal tract length No opportunity for complex normalisation Slide 14 How front is Scottish /u/? hem beam fame hip map boom hum awe hope WC n=8, MC n=7 1 token each Front! Slide 15 Formants and frontness Formants are vocal tract resonances A standard approach for 60 years has been to measure F1 & F2 Low F1 = height & High F2 = frontness We will come back to these metaphors later Nothing is as simple as this metaphor implies, when you get down to detail Higher formants are also important Other factors affect these formants But they are easy to measure, and plot well Slide 16 SSBE for comparison Hawkins and Midgely, cf Wells, Deterding Front! Slide 17 Acoustic analysis Calculate the F2 distance (Bark) from /i/, the vowel with the highest F2 To /o/, /u/ and /e/ for each speaker Repeat for a normalised set by treating the /i/-/o/ distance as 100% (corner vowel to corner vowel), which will make comparison to articulation easier Calculate the distance (Bark) from /i/ To /u/ and /e/ (and /o/) for each speaker It was hard to measure F1 for /a/, so no normalisation Slide 18 Acoustic analysis /u/ is acoustically non-back Relative to each speakers /i/ (& /o/), /u/ is Mid F2 (Hz) Mid-high F2 (Bark) 61% front (from /o/) /e/ has high F2 94% front 2 speakers have /u/ < 50% front (just) Front! Slide 19 Acoustic analysis /u/ and /e/ are significantly non-high /u/ not significantly different to /e/ or /o/ in F1 In 5/14 speakers, /u/ had a higher rel F1 than /e/ Hz / Bark are almost identical at these frequencies Slide 20 /u/ acoustic summary /u/ has a raised F2 2.6 Bark lower than /i/ 4.1 Bark higher than /o/ /u/ has a raised F1 0.6 Bark higher than /i/ Non-distinct from the raised F1 of /e/, 0.4 Bark Slide 21 With UTI We only have mid-sagittal tongue curves Not passive articulators (vocal tract tube) Not all the tongue surface Not all the internal tongue tissue Not lips (well, not for this data set) One token per speaker (for this data set) But unlike EMA We are not limited to 3 or 4 anterior points And unlike MRI UTI is cheap, non-invasive, portable and quick We can collect & trace 12 tokens of 5V in half a day Slide 22 UTI consistently shows Scottish / u / is lower and centralised/fronted compared to other vowels Front! Vowel space (typical WC) Slide 23 Front! Vowel space (typical MC) Slide 24 High point of tongue Whats 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 axes Images can be rotated for quantitative analysis of horizontal and vertical by the analyst Occlusal plane is replicable and standard and provides a reasonable horizontal for the anterior portion of the vocal tract Slide 25 common /o i/ tangent Assumed occlusal ECB08 didnt collect occlusal biteplanes Different shape hard palates dont help Two approaches to estimating horizontal rather than adopting the basic axes of the probe ECB08 Soc-Lx sample Slide 26 Articulatory analysis /u/ is fronter in articulatory space than acoustics /u/ is either more front than central, or fully front 99.6%,