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Ultrasound-based tongue root imaging and measurement

Ultrasound-based tongue root imaging and measurement . James M Scobbie QMU. With thanks to collaborators Jane Stuart-Smith, Marianne Pouplier, Alan Wrench, Eleanor Lawson, Olga Gordeeva. Pros and cons of Ultrasound Tongue Imaging EPG/UTI experiment on English /l/

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Ultrasound-based tongue root imaging and measurement

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  1. Ultrasound-based tongue root imaging and measurement James M Scobbie QMU With thanks to collaborators Jane Stuart-Smith, Marianne Pouplier, Alan Wrench, Eleanor Lawson, Olga Gordeeva

  2. Pros and cons of Ultrasound Tongue Imaging • EPG/UTI experiment on English /l/ • Alveolar contact or vocalisation • Light and dark allophones of /l/ • The ECB08 UTI corpus • Scottish derhoticisation and articulation of /r/ • Vowel system • A handful of /l/ again… • Demo of AAA software Introduction

  3. From qualitative “transcription” to quantitative laboratory-based studies with stabilisation UTI

  4. Pro • Tongue root to blade in one image • Instant, real-time, easy, safe, cheap • Qualitative and quantitative analysis • Can be combined with other techniques • Con • Image quality is variable • Hardly any constriction or info on passive articulator • Frame rate of video output is only ~30Hz (~33ms) • Synchronisation with acoustics is problematic • Quantitative analysis is time-consuming and as yet poorly developed… what to measure? Pros and cons of UTI

  5. Future: corrected high speed data

  6. /l/ is lighter in onset, darker in coda • Many accents have “vocalisation” in coda • EPG + UTI study of 10 speakers • UTI image quality uniformly awful  • EPG results very interesting  • Context was /i/+/l/ (+ {/b/, /h/, /l/}) +/i/ • Pee leewards, peel beavers, peel heaps of, etc. • EPG results • Reduction or loss of alveolar contact in codas • Reduced palatal contact (compared to /i/) due to /l/ English /l/

  7. Alveolar contact in orange, palatal in green • S2 typical in losing palatal contact in onset(can we pee leewardin a gentlebreeze) Example onset

  8. No alveolar contact, more palatal contact(can we peel BBC advertisingfrom the shop window) Example coda_b retraction

  9. E + S1: light onset and dark coda in palatality • Scots S2,3,4 show darker (less [i]-like) onset • Question 1: what about intergestural timing? • Question 2: what about the pharyngeal aspect of darkness rather than loss of palatality? EPG results: loss of palatal contact

  10. Relatively simultaneous alveolar contact and loss of palatality in onset • Alveolar contact is delayed in coda (or missing) and loss of palatality occurs earlier EPG results: timing

  11. Coda = vocalised and darker

  12. Measurement of Tongue root retraction in [i] and in [l] for a single sample speaker S2 • Coping with terrible quality UTI • Find frames of maximum advancement and maximum retraction of root just above hyoid shadow) • Typical problems in measuring images UTI: Scottish pharyngealisation?

  13. Poor image quality • Time and location of root: top of hyoid shadow Example onset

  14. This is only a bit better than guessing, but impression is of slight pharyngealisation Example onset

  15. Tongue root retracts earlier in coda_b (p<0.01) • Max advancement appears to be near end of [i] vowel in onset condition and mid-way through [i] in coda_b condition • Max retraction apparently at end of [l] in onset condition and towards the end of [b] in coda_b condition • [i] is less advanced in coda_b than onset (p<0.005) • There is a n.s. trend for greater pharyngealisation in coda [l] Results (S2, n = 18)

  16. Darkness as measured by decrease in palatality in /i/ context shows onset/coda differences for only some speakers • Probably dialectal: Scots /l/ is less [i]-like in onset • “All” speakers show a strong timing difference • Front and back gestures dissociate in coda so that posterior gesture is earlier and alveolar (if present at all in coda) is later (“gestural dissociation”) • Qualitative (and quantitative) analysis of UTI data probably shows greater pharyngealisation for all speakers’ coda than onset. Conclusions

  17. Ultrasound/acoustic corpus • 15 teenagers (12-14) in friendship pairs (+4 11yrs) • Wordlist and some spontaneous discourse • Half from a WC and half from a MC school • Main purpose to test effect of use of UTI on vernacular speech variables • Secondary purpose • Derhoticisation of coda /r/ - pharyngealisation? • Vowel space • But sadly not much room for • Vocalisation of coda /l/ - pharyngealisation? ECB08

  18. Hiya my name's Kaj McInally My company's FinesseDecor (Scotland) Ltd I'm not a manager. I'm a painter and decorator to trade, first and foremost who just so happened to start work for myself, and then we’ve been that... kinda... successful that we've had to take on people Derhoticised coda /r/

  19. Since the 1970s coda /r/-“loss” has been reported in working class speech • Not the RP-like middle-class non-rhoticity • Stuart-Smith (2003) in a Glasgow corpus including 14-15 year old children showed that WC girls have no overtly rhotic consonant for coda /r/ in approximately 90% of cases, boys in about 80% • Middle class children and older adults are rhotic, so the stratified derhoticisation is indicative of change in progress. • /r/ seems to be turning into a vowel right now • Strong impression of pharyngealisation offglide on vowels with monophthongal pharyngealisation on low back ones Losing /r/ in Scotland

  20. F3 F2 rain, with an anterior approximant, usually described as being “retroflex”(note low F3) ferry, with a tap (an approximant is more common) Typically rhotic tokens of Scottish /r/

  21. F3 F2 F3 F2 Rhotic ear (above) car (below) Derhoticisedear (above) car (below) F3 F2 F3 F2 Word-final derhoticisation in ECB08

  22. Lexical sets BIRD WORD HERD merged (8/11) • Earth, verb, berth, (err) = third, word, surf, birth, fur • Could be a rhotic vowel /ɚ/ • No /a/ split (Pam/palm are homophones) • /ʉ/ is central and not very high iɹ ʉɹ oɹ eɹ ɚ ɔɹ ɑɹ i ʉ o e ı ɔ ɛ a ʌ Rhotic (MC) speakers

  23. MC Edinburgh

  24. WC West Lothian

  25. Phonologically, only /ɛI/ are “lax” Articulation of vowels (EF4)

  26. Tipup (LM17 onset) or tipdown (LM15 onset) Sample ultrasound images of /r/

  27. Tongue blade raising [he] [ɹ] Tongue root retraction [ɹ] [he] [ə] Waterfall time sequence: hair

  28. More vowels (and environments) with weak /r/ • No merger of /ɛr/ and /ʌr/ (8/8) • /a/ split (hat/heart) [a] vs. [ɑ] for the most derhotic • /ʌr/ is short without compensatory lengthening • High vowels create diphthongs • Pre-pausal /r/ tends to devoice • Potential /ʌ/ merger (hut/hurt, bud/bird) i ʉ o e ı ɔ ɛ a ʌ iə ʉə oʌ eə ɔˤ ɛˤ ɑː (ʕ) Derhoticising (WC) speakers

  29. Pre-pausal /r/ may have late (covert?) tip • Low vowels sound derhoticised, acoustically lack F2/F3 approximation, and are near-monophthongs. • Articulatorily a clear rhotic gesture was retained car

  30. Covert rhoticity occurs even in weak syllables and in spontaneous speech

  31. What about /l/? • If dark, is it pharyngealised? • If vocalised, is it a pharyngeal? • How are derhoticised /r/ & vocalised /l/ kept apart? • Hip hum hut • Fur/fir hurt • Pill film • Mull bulb cult • Clear difference between /r/ and /l/ in open and closed syllables /l/ in a derhoticising (WC) speaker

  32. Red = // mull (cons) & bulb (vocalised) • Blue = /ı/ film (cons) & pill (vocalised) • Pharyngealisation vs. velarisation? UTI of laterals

  33. Red = cult (cons /lt/) • Green = hurt (cons /t/) • /l/ pharyngealised + velarised? • Pharyngealised postalveolar /r/ with saddle UTI of laterals

  34. Pharyngealisation and velarisation more extreme than in vowels /l/ compared to /o/ and /ɔ/

  35. Onset/coda differences in /l/ in a high vowel context are well-known to involve loss of palatality and a greater pharyngeal constriction (Sproat and Fujimura 1993), plus subtle loss of alveolar contact (eg Giles & Moll) • Scottish speakers who have no onset/coda difference in palatality do show increased pharyngealisation in coda (and may show very strong vocalisation, not gestural undershoot) • Vocalised /l/ may be velarised while pharyngealisation occurs for consonantal /l/ Conclusions

  36. Derhoticisation often sounds like pharyngealisation • But in prepausal and other masking contexts there can be delayed covert post-alveolar constriction, due to “gestural dissociation” • WC /r/ seems to be changing from consonant into vowel, with some increase in vowel space • Meanwhile, MC rhotic speakers merge vowels • WC /l/ and /r/ seem to be keeping distinct • Is the pharyngealised /l/ also velarised? • Is the difference purely anterior? Conclusions

  37. Let’s look at pharyngealisation in a derhoticising speaker • Hut vs. hurt • Bud vs. bird • Far vs. fir AAA demo

  38. Who says you need ultrasound?

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