My research aims to answer a fundamental question within phonology: which units of representation provide the best fit to the cross-linguistic phonological patterns that we observe? I focus primarily on investigating the advantages and insights gained by adopting sub-segmental units of representation known as gestures. One of the aims of my research involves the reanalysis of persistent theoretical puzzles in phonology within the framework of gestural phonology. I also work to build on some of the core representational concepts of gestural phonology. This includes modifying and expanding upon the established set of gestural parameters, proposing novel types of relations that exist between gestures, and developing a phonological grammar that operates over gestural representations.
On this page, you'll find some of my written work and conference presentation materials, organized thematically. Click one of the tags below to jump directly to a section.
Harmony
Harmony is a widely studied phonological phenomenon that continues to spark debate regarding the nature of triggers (segments that initiate harmony), undergoers (segments that are affected by harmony), so-called neutral segments (segments that apparently do not participate in harmony), and directionality (whether a trigger affects preceding or following segments), among other issues. I address all of these issues via formal phonological analysis and computational modeling. The Gestural Harmony Model that I propose provides long-sought solutions to the representation of harmony that are not available to many feature-based analyses.
In addition to the written works cited below, my 2018 USC dissertation, Harmony in Gestural Phonology, is available on Lingbuzz.
- Adelino, Lucas, Caitlin Smith (2024) Height Harmony and Nasal Vowels: An Argument for Agreement by Correspondence. To appear in Proceedings of NELS 54.
[ poster January 2024 ] [ paper ]
- Smith, Caitlin (2024) Vowel Harmony in Gesture-Based Phonology. In N. A. Ritter & H. van der Hulst (Eds.), The Oxford Handbook of Vowel Harmony (pp. 413-424). Oxford University Press.
[ book chapter]
- Smith, Caitlin (2022) Grammar and Representation Learning for Opaque Harmony Processes (joint work with Charlie O'Hara). Invited talk presented at the Society for Computation in Linguistics.
[ slides February 2022 ] [ github ] [ video ]
- Smith, Caitlin (2021) Learning Derivationally Opaque Patterns in the Gestural Harmony Model (joint work with Charlie O'Hara). Invited talk presented at the Michigan State University Linguistics Colloquium Series.
[ slides November 2021 ]
- Smith, Caitlin (2021) Learning Derivationally Opaque Patterns in the Gestural Harmony Model (joint work with Charlie O'Hara). Invited talk presented at the Keio-ICU Linguistics Colloquium.
[ slides April 2021 ] [ video ]
- Smith, Caitlin, Charlie O'Hara, Eric Rosen, Paul Smolensky (2021) Emergent Gestural Scores in a Recurrent Neural Network Model of Vowel Harmony. In Proceedings of the Society for Computation in Linguistics: Volume 4 (pp. 61-70).
[ paper ] [ slides February 2021 ] [ github ]
- Smith, Caitlin, Charlie O'Hara (2021) Learnability of Derivationally Opaque Processes in the Gestural Harmony Model. In Proceedings of the Society for Computation in Linguistics: Volume 4 (pp. 396-400).
[ paper ] [ poster February 2021 ] [ github ]
- Smith, Caitlin, Charlie O'Hara (2020) Learnability of Derivationally Opaque Patterns in the Gestural Harmony Model. Poster presented at the 2020 Annual Meeting on Phonology.
[ poster September 2020 ] [ video September 2020 ] [ github ]
- Smith, Caitlin (2020) Phonological Idiosyncrasy as Contrastive Gestural Strength. Invited talk presented at the Situating Contrast within the Production-Perception Loop workshop at LabPhon 17.
[ slides July 2020 ]
- Smith, Caitlin (2020) Stepwise Height Harmony as Partial Transparency. In Proceedings of the 50th Annual Meeting of the North East Linguistic Society, Volume 3 (pp. 141-154).
[ paper ] [ slides October 2019 ]
- Smith, Caitlin (2020) Partial Height Harmony as Partial Transparency. In Proceedings of the 2019 Annual Meeting on Phonology.
[ paper ] [ slides October 2019 ]
- Smith, Caitlin (2020) Partial Height Harmony, Partial Transparency, and Gestural Blending. Talk presented at the 94th Annual Meeting of the Linguistic Society of America.
[ slides January 2020 ]
- Smith, Caitlin (2019) Partial Vowel Height Harmony and Partial Transparency via Gestural Blending. Invited talk presented at the Princeton Phonology Forum at Princeton University.
[ slides April 2019 ]
- Smith, Caitlin (2019) Asymmetries in Cross-Height Rounding Harmony. Talk presented at the 93rd Annual Meeting of the Linguistic Society of America.
[ slides January 2019 ]
- Smith, Caitlin (2018) Partial Transparency in Harmony: A Dynamic Gestural Model. Poster presented at the 92nd Annual Meeting of the Linguistic Society of America.
[ poster January 2018 ]
- Smith, Caitlin (2017) Deriving Apparent Exceptionality from Contrastive Gestural Strength. Invited talk presented at the Strength in Grammar workshop at Leipzig University.
[ slides November 2017 ]
- Smith, Caitlin (2017) A Dynamic Model of Partial Transparency in Harmony. Talk presented at the Dynamic Modeling in Phonetics and Phonology workshop at the 53rd Annual Meeting of the Chicago Linguistic Society.
[ slides May 2017 ]
- Smith, Caitlin (2017) Harmony Triggering as a Contrastive Property of Segments. In Supplemental Proceedings of the 2016 Annual Meeting on Phonology.
[ paper ] [ poster October 2016 ]
- Smith, Caitlin (2017) Harmony Triggering as a Segmental Property. In Proceedings of the 47th Annual Meeting of the North East Linguistic Society (pp. 117-126).
[ paper ] [ poster October 2016 ]
- Smith, Caitlin (2016) A Gestural Account of Neutral Segment Asymmetries in Harmony. In Proceedings of the 2015 Annual Meeting on Phonology.
[ paper ] [ slides October 2015 ]
- Smith, Caitlin (2016) Nasal Spreading as Defective Gestural Deactivation. In Supplemental Proceedings of the 2014 Annual Meeting on Phonology.
[ paper ] [ poster October 2014 ]
Machine Learning
Due to the gradient/continuous nature of many gestural parameters, gestural representations are quite powerful and are able to generate many patterns that may not be derivable within feature-based phonological frameworks. However, in order for a phonological pattern to be crosslinguistically attested, it must not only be derivable within a phonological framework, but also learnable within that framework. In collaboration with Charlie O'Hara, I have developed a learning algorithm to computationally model the acquisition of gestural parameters in order to shed light on which phonological patterns are learnable within the gestural phonology framework.
In addition, I have collaborated with several members of Microsoft Research AI on projects involving improving Transformer neural networks' performance by integrating tensor product representations and morphological segmentation.
- Smith, Caitlin, Charlie O'Hara (2022) Two Tools for Learning Gestural Parameters and Constraint Based Grammars. Talk presented at the Computational Approaches to Phonology workshop at the 2022 Annual Meeting on Phonology.
[ slides October 2022 ] [ Google Colab GGLA] [ Google Colab GGGLA]
- Smith, Caitlin (2022) Grammar and Representation Learning for Opaque Harmony Processes (joint work with Charlie O'Hara). Invited talk presented at the Society for Computation in Linguistics.
[ slides February 2022 ] [ github ] [ video ]
- Smith, Caitlin (2021) Learning Derivationally Opaque Patterns in the Gestural Harmony Model (joint work with Charlie O'Hara). Invited talk presented at the Michigan State University Linguistics Colloquium Series.
[ slides November 2021 ]
- Jiang, Yichen, Asli Celikyilmaz, Paul Smolensky, Paul Soulos, Sudha Rao, Hamid Palangi, Roland Fernandez, Caitlin Smith, Mohit Bansal, Jianfeng Gao (2021) Enriching Transformers with Structured Tensor-Product Representations for Abstractive Summarization. In Proceedings of the 2021 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies (pp. 4780-4793).
[ paper ]
- Smith, Caitlin (2021) Learning Derivationally Opaque Patterns in the Gestural Harmony Model (joint work with Charlie O'Hara). Invited talk presented at the Keio-ICU Linguistics Colloquium.
[ slides April 2021 ] [ video ]
- Smith, Caitlin, Charlie O'Hara, Eric Rosen, Paul Smolensky (2021) Emergent Gestural Scores in a Recurrent Neural Network Model of Vowel Harmony. In Proceedings of the Society for Computation in Linguistics: Volume 4 (pp. 61-70).
[ paper ] [ slides February 2021 ] [ github ]
- Smith, Caitlin, Charlie O'Hara (2021) Learnability of Derivationally Opaque Processes in the Gestural Harmony Model. In Proceedings of the Society for Computation in Linguistics: Volume 4 (pp. 396-400).
[ paper ] [ poster February 2021 ] [ github ]
- Smith, Caitlin, Charlie O'Hara (2020) Learnability of Derivationally Opaque Patterns in the Gestural Harmony Model. Poster presented at the 2020 Annual Meeting on Phonology.
[ poster September 2020 ] [ video September 2020 ] [ github ]
Opacity
In cases of underapplication opacity, a phonological process does not occur when it 'should' have based on its structural description. While earlier rule-based phonological frameworks often dealt with opacity via extrinsic rule ordering, more recent attention has been paid to the inability of many versions of output-driven Optimality Theory and Harmonic Grammar to derive opaque patterns. In collaboration with Charlie O'Hara, I have shown that gestural phonology allows us to represent some seemingly opaque processes as derivationally transparent. Furthermore, we have shown that the mechanisms that drive apparent opacity in gestural phonology correctly predict typological asymmetries between chain shifts and saltations, two types of underapplication opacity.
- O’Hara, Charlie, Caitlin Smith (2024) Typological Asymmetries in Underapplication Opacity: A Gestural Account. In J. Lu, E. Petersen, A. Zaitsu, & B. Harizanov (Eds.), Proceedings of the 40th West Coast Conference on Formal Linguistics (pp. 265-274). Cascadilla Proceedings Project.
[ paper ] [ slides May 2022 ]
- Smith, Caitlin (2022) Grammar and Representation Learning for Opaque Harmony Processes (joint work with Charlie O'Hara). Invited talk presented at the Society for Computation in Linguistics.
[ slides February 2022 ] [ github ] [ video ]
- Smith, Caitlin (2021) Learning Derivationally Opaque Patterns in the Gestural Harmony Model (joint work with Charlie O'Hara). Invited talk presented at the Michigan State University Linguistics Colloquium Series.
[ slides November 2021 ]
- Smith, Caitlin, Charlie O'Hara (2021) Learnability of Derivationally Opaque Processes in the Gestural Harmony Model. In Proceedings of the Society for Computation in Linguistics: Volume 4 (pp. 396-400).
[ paper ] [ poster February 2021 ] [ github ]
- Smith, Caitlin, Charlie O'Hara (2020) Learnability of Derivationally Opaque Patterns in the Gestural Harmony Model. Poster presented at the 2020 Annual Meeting on Phonology.
[ poster September 2020 ] [ video September 2020 ] [ github ]
- Smith, Caitlin (2020) Stepwise Height Harmony as Partial Transparency. In Proceedings of the 50th Annual Meeting of the North East Linguistic Society, Volume 3 (pp. 141-154).
[ paper ] [ slides October 2019 ]
- Smith, Caitlin (2020) Partial Height Harmony as Partial Transparency. In Proceedings of the 2019 Annual Meeting on Phonology.
[ paper ] [ slides October 2019 ]
- Smith, Caitlin (2020) Partial Height Harmony, Partial Transparency, and Gestural Blending. Talk presented at the 94th Annual Meeting of the Linguistic Society of America.
[ slides January 2020 ]
- Smith, Caitlin (2019) Partial Vowel Height Harmony and Partial Transparency via Gestural Blending. Invited talk presented at the Princeton Phonology Forum at Princeton University.
[ slides April 2019 ]
Phonological Exceptionality
Phonological exceptionality refers to cases in which individual segments or lexical items pattern in an idiosyncratic or unpredictable way with respect to one or more phonological processes. My research in this area gives gestural parameters, including gestural self-(de)activation and blending strength, expanded roles as not only sources of coarticulatory influence but also as phonologically active elements of representation. These gestural parameters can be used to reanalyze cases of phonological idiosyncrasy previously thought to be the result of absolute surface neutralization, derivational opacity, or lexical exceptionality. Portions of this work have been conducted in collaboration with Reed Blaylock. I have also pursued work in collaboration with Brian Hsu analyzing phonological idiosyncrasy within the framework of Gradient Harmonic Grammar.
- Hsu, Brian, Caitlin Smith (2024) Emergent Strength Strata in Cherokee Hiatus Resolution. In preparation for Proceedings of NELS 55.
[ slides October 2024 ] [ paper coming soon ]
- Hsu, Brian, Caitlin Smith (2023) Idiosyncratic Hiatus Resolution: An Argument for Gradient Harmonic Grammar. In Supplemental Proceedings of the 2022 Annual Meeting on Phonology.
[ poster October 2022 ] [ paper ]
- Smith, Caitlin (2020) Phonological Idiosyncrasy as Contrastive Gestural Strength. Invited talk presented at the Situating Contrast within the Production-Perception Loop workshop at LabPhon 17.
[ slides July 2020 ]
- Smith, Caitlin (2018) Partial Transparency in Harmony: A Dynamic Gestural Model. Poster presented at the 92nd Annual Meeting of the Linguistic Society of America.
[ poster January 2018 ]
- Smith, Caitlin (2017) Deriving Apparent Exceptionality from Contrastive Gestural Strength. Invited talk presented at the Strength in Grammar workshop at Leipzig University.
[ slides November 2017 ]
- Smith, Caitlin (2017) A Dynamic Model of Partial Transparency in Harmony. Talk presented at the Dynamic Modeling in Phonetics and Phonology workshop at the 53rd Annual Meeting of the Chicago Linguistic Society.
[ slides May 2017 ]
- Smith, Caitlin, Reed Blaylock (2017) Deriving Exceptional Phonological Patterns from Contrastive Gestural Strength. Poster presented at the Dynamic Modeling in Phonetics and Phonology workshop at the 53rd Annual Meeting of the Chicago Linguistic Society.
[ poster ]
- Smith, Caitlin (2017) Harmony Triggering as a Contrastive Property of Segments. In Supplemental Proceedings of the 2016 Annual Meeting on Phonology.
[ paper ] [ poster October 2016 ]
- Smith, Caitlin (2017) Harmony Triggering as a Segmental Property. In Proceedings of the 47th Annual Meeting of the North East Linguistic Society (pp. 117-126).
[ paper ] [ poster October 2016 ]
Computational Complexity
Formal language theory provides a way of hierarchically classifying phonological patterns according to their relative degrees of computational complexity. In collaboration with Charlie O'Hara and Andrew Lamont, I have investigated how the formal complexity of different types of mappings, especially those involving featural and tonal spreading, affects cross-linguistic typological patterns. In particular, we focus on determining the upper bound on the complexity of attested spreading patterns.
- Lamont, Andrew, Charlie O'Hara, Caitlin Smith (2019) Weakly Deterministic Transformations are Subregular. In Proceedings of the 16th Workshop on Computational Research in Phonetics, Phonology, and Morphology (pp. 196-205).
[ paper ]
- O'Hara, Charlie, Caitlin Smith (2019) Computational Complexity and Sour-Grapes-Like Patterns. In Supplemental Proceedings of the 2018 Annual Meeting on Phonology.
[ paper ] [ poster October 2018 ]
- Smith, Caitlin, Charlie O'Hara (2019) Formal Characterizations of True and False Sour Grapes. In Proceedings of the Society for Computation in Linguistics: Volume 2 (pp. 338-341).
[ paper ] [ slides January 2019 ]
- O'Hara, Charlie, Caitlin Smith (2018) Weakly Deterministic Characterizations of Unbounded Tonal and Featural Spreading. Talk presented at the Southern California April Meeting in Phonology, Los Angeles, CA.
[ slides April 2018 ]
Morphological Consonant Mutation
Morphological consonant mutation is characterized by the marking of morphological information via alteration of a root consonant rather than the addition of an overt affixal segment or string. I claim that by adopting gestural representations it is possible to represent morphological consonant mutation as the affixation of a gesture rather than a feature that must dock with a segment in the stem. This both eliminates the need to distinguish between segmental and featural affixation, and makes more restricted typological predictions regarding what kinds of consonant mutations we can expect to observe.
- Smith, Caitlin (2016) Morphological Consonant Mutation as Gestural Affixation. In Papers from the 50th Annual Regional Meeting of the Chicago Linguistic Society.
[ paper ] [ handout April 2014 ]
Speech Production
In my work on articulatory phonetics, I use the results of phonetic experimentation (usually taking the form of real-time MRI data) to inform phonological analysis and representation. The work I have conducted in this area is aimed at answering questions regarding the often complex nature of lingual control during the production of coronal consonants, especially liquids. This work was conducted as part of my membership in USC's Speech Production and Articulation kNowledge (SPAN) group and in collaboration with several of its members.
- Lim, Yongwan, Asterios Toutios, Yannick Bliesener, Ye Tian, Sajan Lingala, Colin Vaz, Tanner Sorensen, Miran Oh, Sarah Harper, Weiyi Chen, Yoonjeong Lee, Johannes Töger, Mairym Montesserin, Caitlin Smith, Bianca Godinez, Louis Goldstein, Dani Byrd, Krishna Nayak, Shrikanth Narayanan (2021) A multispeaker dataset of raw and reconstructed speech production real-time MRI video and 3D volumetric images. Scientific Data 8, 187.
[ paper ]
- Proctor, Michael, Rachel Walker, Caitlin Smith, Tünde Szalay, Louis Goldstein, Shrikanth Narayanan (2019) Articulatory characterizations of English liquid-final rimes. Journal of Phonetics 77.
[ paper ]
- Walker, Rachel, Michael Proctor, Caitlin Smith, Ewald Enzinger (2016) Asymmetries in English Liquid PRoduction and Vowel Interactions. Poster presented at LabPhon 15.
[ poster July 2016 ]
- Smith, Caitlin (2014) Complex Tongue Shaping in Lateral Liquid Production Without Constriction-Based Goals. In Proceedings of the 10th International Seminar on Speech Production (pp. 413-416).
[ paper ] [ poster May 2014 ]
- Smith, Caitlin, Michael Proctor, Khalil Iskarous, Louis Goldstein, Shrikanth Narayanan (2013) Stable articulatory tasks and their variable formation: Tamil retroflex consonants. In Proceedings of the 14th Annual Conference of the International Speech Communication Association (pp. 2006-2009).
[ paper ] [ slides August 2013 ]
- Smith, Caitlin, Adam Lammert (2013) Identifying consonantal tasks via measures of tongue shaping: a real-time MRI investigation of the production of vocalized syllabic /l/ in American English. In Proceedings of the 14th Annual Conference of the International Speech Communication Association (pp. 3230-3233).
[ paper ] [ poster August 2013 ]
- Smith, Caitlin, Michael Proctor, Khalil Iskarous, Louis Goldstein, Shrikanth Narayanan (2013) On distinguishing articulatory configurations and articulatory tasks: Tamil retroflex consonants. Journal of the Acoustical Society of America 133(5), 3609 (abstract).
[ poster June 2013 ]