Gestural Timing and Magnitude of English /r/: An Ultrasound-OptoTrak Study Fiona Campbell, Bryan Gick, Ian Wilson, and Eric Vatikiotis-Bateson Ultrafest IV Tucson, Arizona April 14, 2005

Goals  To better understand the gestural organization of composite segments in English.  Contribute to the knowledge of mechanisms for production of English /r/  Improve on past methodology by testing combined B/M-mode ultrasound and Optotrak as a means to increase temporal resolution while imaging the vocal tract from lips to tongue root.

Introduction  Generalizations from previous studies: Temporal: More anterior gestures appear at syllable peripheries. Nasals, /l/, /w/ (Krakow, 1999; Gick, 2003) Spatial: Position-dependent spatial reduction of gestures. (Sproat & Fujimura, 1993) Final position reduction of anterior gestures & Initial position reduction of less anterior gestures

Proposed Explanations  A number of explanations have been proposed to account for these generalizations, including: Sproat & Fujimura (1993) Browman & Goldstein (1995) Gick (2003) Carter (2002) Gick, Campbell, Oh, and Tamburri-Watt (in press)  All studies thus far have been based on a comparison of two gestures

English /r/  Composed of 3 constrictions: tongue root at the pharyngeal wall (TR) tongue tip/blade at the palate(TB) between the lips (Lip)  Variable tongue shape, more lip rounding and more prominent TB gesture in Initial position. (Zawadzki & Kuehn, 1980)  Examination of three gestures will help disambiguate the predictions made by different theories.

Predictions Summary of predicted categorization of gestures and predictions of relative timing by position: LipTBTRInitialFinal Sproat & Fujimura (1993) [vocalic] All three simultaneous, All three reduced All three simultaneous, No reduction Browman & Goldstein (1995) narrower constriction (than TR) narrower constriction (than TR) wider constriction All three simultaneous. TR > Lip TR > TB TB & Lip reduced Gick (2003)C-gesture V-gestureLip & TB > TR, TR reduced TR > Lip & TB Lip & TB reduced Carter (2002) ?seemingly consonantal seemingly vocalic Any order: dialect dependent (Lip)/TR > TB/(Lip) Gick et al (in press) anteriorless anteriorleast anterior All three simultaneous TR > TB > Lip

Methods  Optotrak 3D motion and position measurement (point tracking) system and B/M-mode ultrasound video were used to simultaneously record the three gestures of /r/ in syllable-initial, and syllable-final positions preceding a consonant and preceding a vowel in several vocalic contexts.

Participants  10 people, 5 women, 5 men  Native speakers of Canadian English  8 from Western Canada  One of the male subjects had to be excluded from the analysis due to poor ultrasound image quality.

Stimuli The position of /r/ varied within a given vocalic context such that: Syllable-initialResyllabifiableSyllable-final...V 1 # RV V 1 R# V V 1 R# hV 1... V 1 = /e/ (Lips, TR visible) V 1 = /a/ (Lips, TB visible) Stimuli were randomized and presented in a carrier phrase which was read by the subject. … said “ _________ ” each … x 10 for each stimulus eg. Cindy said "hay ray" each afternoon.

Data Collection  The subject was seated in a modified ophthalmic examination chair to maximize head stability and Ultrasound probe contact.  Stimuli were presented on a laptop located about 2m away from the subject at eye level.  Timed PowerPoint presentation: 130s trials  A 'clapper' with an Optotrak marker attached was used to set a 0 point for synchronization of the Optotrak, Ultrasound, and Audio signals.

Experimental Set-up

Data Collection II  Ultrasound: B/M mode: midsagittal section (29.97fps) + continuous movement trajectories of A (TT), B (TM), C (TR) recorded to DV.  Optotrak 3020 system: recorded (at 90 Hz) the 3D positions of 12 infrared-emitting diode Optotrak markers.  Audio: signal recorded synchronized with both Optotrak and Ultrasound data signals.

Optotrak Marker Placement

Ultrasound Data

Ultrasound Measures: Timing

Ultrasound Measures: Magnitude

Optotrak Measures

Qualitative Observations Sagittal diagram of idealized tongue shapes for American /r/ (Modified from Hagiwara, 1995, p.97) Tip Down Blade Up Tip Up

Results: Timing

Results: Magnitude

Qualitative Results  All three tongue shapes observed  No speaker used more than two of these  ‘blade up’ was most common across subjects and most stable across positions  Tongue shape varied by both vowel context and syllable position  Higher TB syllable-initially and in the context of low or back vowels

Tongue Shape Variability

Summary  The position-based differences observed in the overall results were: Initial Timing: front-to-back Spatial reduction: TR Final: Timing: TR & Lip simultaneous; precede TB Spatial reduction: TB and Lips

Surprises?  Three-way timing distinction in Initial position  Lip patterns with TR in terms of timing but with TB in terms of spatial reduction in Final position  The results are not consistent with any of the proposals considered

Proposal  Timing patterns depend on magnitude Relative width of constrictions determines order (Browman & Goldstein, 1995, but in both positions). Narrower constriction(s) at syllable edges Relative width can vary as a result of positional reduction  Possible motivating factor: Constriction width: Jaw height

Potential Problems  Potential for error in calculations  Unclear data for Resyllabifiable condition  Stationary M-mode lines, variable tongue shape  No head correction

Conclusions  Accounts employing a binary categorical system are challenged by the observed three-way timing distinction in Initial position.  The results of this study suggest a dependence relationship between the relative timing of gestures and their magnitude.  Future work may be able to test this proposal by measuring the actual relative constriction width of each gesture across positions.

Selected References Browman, C. P., & Goldstein, L. (1992). Articulatory phonology: An overview. Phonetica, 49, Carter, P. (2002). Structured variation in british english liquids: The role of resonance. Unpublished PhD Dissertation, University of York. Delattre, P., & Freeman, D. (1968). A dialect study of american r’s by x-ray motion picture. Linguistics, 44, Gick, B. (1999). A gesture-based account of intrusive consonants in english. Phonology, 16, Gick, B. (2003). Articulatory correlates of ambisyllabicity in english glides and liquids. In J. Local, R. Ogden & R. Temple (Eds.), Labphon VI: Constraints on phonetic interpretation. Cambridge: Cambridge University Press. Gick, B., Campbell, F., Oh, S., & Tamburri-Watt, L. (in press). Toward universals in the gestural organization of syllables: A cross-linguistics study of liquids. Journal of Phonetics. Hagiwara, R. (1995). Acoustic realizations of american /r/ as produced by women and men. UCLA Working Papers in Phonetics, 90, Krakow, R. A. (1999). Physiological organization of syllables: A review. Journal of Phonetics, 27, Sproat, R., & Fujimura, O. (1993). Allophonic variation in english /l/ and its implications for phonetic implementation. Journal of Phonetics, 21, Uldall, E. (1958) ‘American “molar” R and “flapped” T.’ Revista do Laboratorio de Fonetica Experimental, Universidad de Coimbra Zawadzki, P. A., & Kuehn, D. P. (1980). A cineradiographic study of static and dynamic aspects of american english /r/. Phonetica, 37,