1. Ultrafest 3 U. Arizona, April 2005 Measuring the tongue root: Image dropoff, rotation issues, and the siren call of intrinsic F0 D. H. Whalen Haskins Laboratories Leonardo Oliveira Haskins Laboratories and Yale University Khalil Iskarous Haskins Laboratories

2. Ultrafest 3 U. Arizona, April 2005 Plumbing the depths of the pharynx One great advantage of ultrasound over point parameterization systems (like x-ray microbeam and electromagnetometry) is the ability to view the pharynx. MRI also images this area, with its attendant differences. –Supine position, loud background noise, high cost, relatively slow acquisition time.

3. Ultrafest 3 U. Arizona, April 2005 Pharyngeal shape is important Evident from early x-ray work. –E.g. Russell, 1928. Covaries with tongue height in most languages. –IPA bases vowel symbols only on height. Distinctive in some languages. –+/- ATR vowel distinctions.

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5. Ultrafest 3 U. Arizona, April 2005 Optically Corrected Ultrasound Ultrasound allows imaging of the tongue root in transceiver-relative space. Adding optical markers that are tracked in 3-D allows for the tongue data to be related to the rest of the vocal tract (head-relative space). –E.g., HOCUS, the Haskins Optically Corrected Ultrasound System (Whalen et al., 2005).

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12. Ultrafest 3 U. Arizona, April 2005 Pharynx shape The rear pharyngeal wall does not appear to move significantly during speech. –Magen et al., 2003. This allows us to treat tongue root as an indicator of pharyngeal depth. Absolute values for this are probably affected by posture.

13. Ultrafest 3 U. Arizona, April 2005 Imaging challenges The image of the pharynx is not always robust. With vowels like /i/, the tongue root is parallel to the ultrasound signal, making imaging difficult. Signals near the hyoid bone shadow do not appear to be reliable.

14. Ultrafest 3 U. Arizona, April 2005 Dropoff Almost unavoidable, at both ends of the tongue. –Although most easily-imaged tongues image most of the way to the tip (Gick, p.c.). Hard to distinguish changes in image from changes in tongue length.

15. Ultrafest 3 U. Arizona, April 2005 Solutions Leave spline as just what the image justifies. –Makes comparisons with other images difficult. –But it is the most conservative. Extend or truncate to a standard. –Makes comparisons easier. –Loses or creates data. –Ignores genuine length differences. –Extensions in the pharynx are probably more reliable than those for the tip.

16. Ultrafest 3 U. Arizona, April 2005 Testing the methods We could truncate the spline even though there is data; then reconstruct the spline and compare with the original spline. –Area differences. –Confidence intervals (Davidson) This could give us a way of knowing whether we should ever extend our splines.

17. Ultrafest 3 U. Arizona, April 2005 Intrinsic F0 Intrinsic F0 (IF0) is the tendency for high vowels to have high F0s across languages. –Whalen and Levitt, 1995. Evidence indicates it is an automatic consequence of vowel articulation. –Whalen et al., 1998

18. Ultrafest 3 U. Arizona, April 2005 Tongue height vs. pharynx depth IF0 has been described as due to tongue height. Because tongue height and pharynx depth covary, it is equally plausible to describe IF0 as an effect of pharyngeal depth. Is one or the other more responsible?

19. Ultrafest 3 U. Arizona, April 2005 First pass at measurement We collected HOCUS data on English keywords (“heed”, “aid”, etc.) for two male speakers. This allowed us to look at a variety of tongue shapes. Tongue depth was taken as the lateral measurement at a single level for the fitted splines for all vowels. Tongue height was the highest point on the spline curve.

20. Ultrafest 3 U. Arizona, April 2005 F0 data F0 values were typical: i I u U a S1: 110 109 117 112 102 S2: 125 115 125 134 107

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22. Ultrafest 3 U. Arizona, April 2005 Tongue shapes for five vowels The next two slides show the shapes for /i I u U a/ for the two speakers.

23. Ultrafest 3 U. Arizona, April 2005 i -- red I -- blue u -- green U -- cyan a -- black

24. Ultrafest 3 U. Arizona, April 2005 i -- red I -- blue u -- green U -- cyan a -- black

25. Ultrafest 3 U. Arizona, April 2005 Correlation of height and depth Tongue height and pharyngeal depth were correlated (r =.87 and.72). Though large, this left a fair amount of variance which might allow for one or the other measure to do a better job of explaining differences in F0.

26. Ultrafest 3 U. Arizona, April 2005 Correlations with F0 Correlations of F0 with depth were significant: – r = 33. and.17 for the two speakers. Correlations of F0 with height were significant: – r =.43 and.29 for the two speakers. Correlations with height were larger.

27. Ultrafest 3 U. Arizona, April 2005 Caveats The F0 was not as controlled as would be optimal for this study. –Various techniques are being tried in the next version. Tongue height had less intrinsic variability, since it was selected as the highest point of all. –This may have given it an edge in the correlation measure. The level at which the pharynx was measured may not have been optimal.

28. Ultrafest 3 U. Arizona, April 2005 Summary New evidence can address issues that have been glossed over before. Addressing IF0 in ATR languages is a further step we would like to take. Even the English data will be more informative as we tune up the system.

29. Ultrafest 3 U. Arizona, April 2005 Some thoughts for UF4 Compare variability of utterances from some of the same speakers on different systems. Compare surfaces extracted by various systems. –Data from various labs. –Use all methods described here. –Compare lengths, curves, and conic sections.

30. Ultrafest 3 U. Arizona, April 2005 Quantify probe-space data For those systems that put data into head- relative space, see what the quantification of the data looks like in probe-relative space. This will allow us to know more of what we can say for applications that can’t/don’t use head correction. –Field, speech pathology, L2 learning, etc.

31. Ultrafest 3 U. Arizona, April 2005 What should we measure? Height and anteriority: Is the occlusal plane good enough? Constriction location: –minimum distance from hard structures for vowels? –Midpoint of contact for stops? (Compare with EPG.) –Difficult for fricatives on midline? –Inflection factor in conic section? –Inclusion of off-midline? (measured or inferred.)

32. Ultrafest 3 U. Arizona, April 2005 Working Groups Machines, manufacturers, probes and settings. Compensation for head and probe movement. 3D Surface fitting. Time alignment. Field issues. Feedback issues. Cp. US to point param (EM(M)A, XRMB). Posture issues. Putting in the hard/fixed structures What to measure.

33. Ultrafest 3 U. Arizona, April 2005 Acknowledgements Thanks! Funding provided by NIH grants DC- 02717, HD-01994, and DC-00493.

34. Ultrafest 3 U. Arizona, April 2005 References Magen, H. S., Kang, A. M., Tiede, M. K., & Whalen, D. H. (2003). Posterior pharyngeal wall position in the production of speech. Journal of Speech, Language, and Hearing Research, 46, 241-251. Russell, G. O. (1928). The vowel: Its physiological mechanism as shown by x-ray. Columbus, OH: Ohio State University Press. Whalen, D. H., Gick, B., Kumada, M., & Honda, K. (1998). Cricothyroid activity in high and low vowels: Exploring the automaticity of intrinsic F0. Journal of Phonetics, 27, 125-142. Whalen, D. H., Iskarous, K., Tiede, M. K., Ostry, D. J., Lehnert- LeHouillier, H., Vatikiotis-Bateson, E., et al. (2005). HOCUS, the Haskins Optically-Corrected Ultrasound System. Journal of Speech, Language, and Hearing Research. Whalen, D. H., & Levitt, A. G. (1995). The universality of intrinsic F0 of vowels. Journal of Phonetics, 23, 349-366.