Director, Vocal Tract Visualization Lab. University of Maryland Dental School,
Department of Oral and Craniofacial Biological Sciences (OCBS)
Department of Orthodontics. mstone@umaryland.edu

Phonetics, physiology, speech science, speech production, speech acoustics, vocal tract modelling, tongue modelling, speech motor control, ultrasound, electropalatography, MRI speech instrumentation, vocal tract measurement.

Stone, Maureen, Professor, OCBS and Orthodontics. Ph.D. University of Maryland, M.S. Boston University, B.A. Queens College CUNY. Research: I am particularly interested in understanding the behavior of the tongue and vocal tract. The vocal tract is a complex system and the tongue is its major articulator, accounting for most of the shape and motion used in speech and swallowing. Our lab uses a multi-instrumental approach to develop and examine models of tongue and vocal tract function. The first goal is to represent 3D-tongue motion accurately and simply. We use statistical models (e.g. PCA, polynomial functions) and mechanical models (e.g. global and local deformation models). Data come primarily from three measurement instruments: ultrasound, tagged Cine-MRI (tMRI), and electropalatography (EPG). Ultrasound provides planar surface motion at multiple locations. These 2D surface contours are real-time (30 Hz), and can be reconstructed into 3D tongue surface motion. EPG data, collected simultaneously with the ultrasound, provides continuous tongue-palate contact information during the task. tMRI captures the motion of local tissue points in the tongue. Multiplanar tMRI data are used to reconstruct 3D volumetric deformation patterns from which 3D principal strains are calculated. The second goal is to map muscle activity to tongue surface shape using predictive models (e.g., FEM). Muscle contraction patterns are inferred from the raw data and the models. The contraction patterns are input into finite element models that predict tongue surface shapes. The model outputs are tested against ultrasound and MRI data The models are used to address topical questions in speech science and to study normal and disordered speech and swallowing.

1. Statistical and geometrical analyses to quantify biologically important features of tongue surface shapes, including principal components analysis, polynomial curve fitting and extended superquadrics.
2. 3D reconstruction of the vocal tract using tagged-cine MRI data during speech.
3. Representive Modelling of the tongue using kinematic principals (bend, stretch, shear, etc).
4. Predictive Modeling of the tongue using Finite Element Analysis.

Slud, E., Smith, P., Stone, M., and Goldstein, M. (2002) “Principal Components Representation of the Two-Dimensional Coronal Tongue Surface.” Phonetica vol. 59,  Nos. 2-3, pp. 108-133.

Yang, CS., and Stone, M., (2002) “Dynamic Programming Method for Temporal Registration of Three-Dimensional Tongue Surface Motion From Multiple Utterances.” Speech Communication.  Vol. 38, Nos. 1-2, September 2002, pp. 199-207.

Iny, D., Lundberg, A., Levine, W., and Stone, M. (2001) "The dynamics and control of the tongue during speech." Proceedings of the American Control Conference, June 25-27, Arlington, VA.

Stone, M., Davis, E., Douglas, A., Ness Aiver, M., Gullapalli, R., Levine, W., and Lundberg, A. (2001) "Modeling motion of the internal tongue from tagged cine-MRI images." J. Acoust. Soc. Am., 109(6), 2974-2982.

Stone, M., Davis, E., Douglas, A., Ness Aiver, M., Gullapalli, R., Levine, W., and Lundberg, A. (2001) "Modeling Tongue Surface Contours from Cine-MRI images." Journal of Speech, Language, and Hearing Research, 44(5)-Oct, 1026-1040

 Stone, M., Dick, D., Douglas, A., Ozturk, C., Shechter, G., Guttman, M. (June, 2001) “Extracting Tongue Muscle Contraction Patterns from Tagged Cine-MRI.”

Journal of the Acoustical Society of America , 109  (5), 2446A.

Stone, M., Dick, D., Davis, E., Douglas, A., and Ozturk, C. (2000) "Modeling the Internal Tongue using Principal Strains." Proceedings of the 5th Speech Production Seminar, Kloster-Seeon, Germany, 133-136.

Dick, D., Ozturk, C., Douglas, A., McVeigh, E., Stone, M. (2000) "Three-Dimensional Tracking of Tongue Motion using Tagged MRI." International Society for Magnetic Resonance in Medicine, 8th Scientific Meeting and Exhibition, Denver, CO.  April 1-7, 2000.

Stone, M. and Lundberg, A. (1999) "Three-dimensional tongue reconstruction: Practical considerations for ultrasound data." J. Acoust. Soc. Am., 106, 2858-2867.

Akgul, Y., Kambhamettu, C., and Stone, M. (1999) "Automatic Extraction and Tracking of the Tongue Contours." IEEE Transactions on Medical Imaging, 18, 1035-1045.

Sze, C-F, Iny, D., Stone, M. and Levine, W. (1999) "Reconstructing Three-dimensional Tongue Motion from Ultrasound Images." Proceedings of the Conference of the International Federation for Automatic Control (IFAC), Beijing, China, Vol. I, 97-102.

Akgul, Y., Kambhamettu, C., and Stone, M. (1998) "Extraction and Tracking of the Tongue Surface from Ultrasound Image Sequences." Proceedings of the IEEE Conference on Computer Vision and Pattern Recognition , (CVPR), 289-303.

Akgul, Y., Kambhamettu, C., and Stone, M. (1998) "Automatic Motion Analysis of Tongue Surfaces from Ultrasound Image Sequences." Proceedings of the IEEE Workshop on Biomedical Analysis, Santa Barbara, CA., 126-132.

Akgul, Y., Kambhamettu, C., and Stone, M. (1998) "Analysis of the tongue surface movement using a spatiotemporally coherent deformable model." Proceedings of the IEEE Workshop on Applications of Computer Vision, Princeton, NJ., 109-114.

Chi-Fishman, G., Stone, M. and McCall, G. (1998) "Lingual Action in Normal Sequential Swallowing." Journal of Speech and Hearing Research., 41, 771-785.

Ong, D. and Stone, M. (1998) "Three-dimensional vocal tract shapes in [r] and [l]: A study of MRI, Ultrasound, Electropalatopgraphy, and Acoustics." Phonoscope, 1, 1-14.

Stone, M., Lundberg, A., Davis, E., Gullapalli, R., and Ness Aliver, M. (1997) "Three-dimensional coarticulatory strategies of tongue movement." Proceedings of the 5th European Conference on Speech Communications and Technology, Rhodes, Greece, 1, 31-34.

Stone, M., Goldstein, M., and Zhang, Y. (1997) "Principal component analysis of cross-sectional tongue shapes in vowels." Speech Communication., 22, 173-184

Chi-Fishman, G. and Stone, M. (1996) "A new application for electropalatography: Swallowing." Dysphagia, 11, 239-247.

Davis, E., Douglas, A., and Stone, M. (1996) "A continuum mechanics representation of tongue motion in speech." Proceedings of the 4th International Conference on Spoken Language Processing, Philadelphia, PA., 2, 788-792.

Stone, M. and Lundberg, L. (1996) ``Three-dimensional tongue surface shapes of English consonants and vowels.'' J. Acoust. Soc. Am., 99(6), 1-10.

Stone, M. and Davis, E.P. (1995) ``A head and transducer support system for making ultrasound images of tongue/jaw movement.'' J. Acoust. Soc. Am., 98(6), 3107-3112.

Stone, M. (1995) ``How the Tongue Takes Advantage of the Palate During Speech'' Producing Speech: Contemporary Issues, Bell-Berti, F. and Raphael, L.J., eds., AIP Series in Modern Acoustics and Signal Processing, AIP Press, 143-153.

Stone, M. and Vatikiotis-Bateson, E, (1995) ``Trade-offs in tongue, jaw and palate contributions to speech production.'' J. of Phonetics., 23, 81-100.

Stone, M. and Lundberg, A. (1994) ``Tongue-palate interactions in consonants vs. vowels.'' Proceedings of the Third International Conference on Spoken Language Processing, Yokohama, Japan, v.1, 49-52.

Stone, M., Faber, A., Raphael, L.J. and Shawker, T.H. (1992) ``Cross-sectional tongue shape and linguopalatal contact patterns in [s],[sh], and [l]'' J. of Phonetics, 20, 253-270

Stone, M. (1991) ``Toward a three dimensional model of tongue movement.'' J. of Phonetics, 19, 309-320.

Stone, M. (1991) ``Imaging the tongue and vocal tract.'' British Journal of Disorders of Communication. 26, 11-23.

Stone. M, Shawker, T., Talbot, L., Rich, A. (1988) ``Cross-sectional Tongue Shape During the Production of Vowels.'' Journal of the Acoustical Society of America 83(4), 1586-1596.