Structure in phonetic variability
When we talk we produce an acoustic signal that is rich and multidimensional. The acoustic cues signaling speech categories and words are spread across different acoustic dimensions and vary according to the immediate phonetic context, the prosodic structure, the speech style and even who is talking. This highly variable signal provides the raw material for the listener who must integrate aross dimensions and simultaneously extract many layers of information. We are interested in understanding both the structure of this signal and how listeners exploit it. We are examining how talkers differ in how they signal categories, and how higher level information like prominence due to information structure or mishearing and produciton planning influence phonetic cues. We also examine if and how listeners are able to make use of this information in real time as they understand language.
Clayards, M., Niebuhr, O., Gaskell, M.G. (2015) The time course of auditory and language-specific mechanisms in compensation for sibilant assimilation. Attention, Perception & Psychophysics. 77:1, 311-328. doi:10.3758/s13414-014-0750-z
Clayards, M., Knowles, T. (2015) Prominence enhances voiceless-ness and not place distinction in English voiceless sibilants. Proceedings of the International Congress of Phonetic Sciences, Glasgow, UK. [Online]
Wagner, M., Clayards, M. (2013, July 12) Syntactic effects on variable phonological processes and the locality of production planning. Oral presentation at LSA 13 Workshop: Universality and variability in segment prosody interactions. Ann Arbor, MI.
Clayards, M., Hawkins, S., Gaskell, G. (2012, Sept) Listeners decode acoustic-phonetic cues to morphological structure. Oral presentation at Architectures and Mechanisms of Language Processing (AMLaP), Riva del Garda, Italy.
Mackenzie, S., Olson, E., Clayards, M., Wagner, M. (2012, July) The role of allophonic variation in speech segmentation. Poster presented at LabPhon 13, Stuttgart, Germany. [Poster]
Niebuhr, O., Clayards, M., Meunier, C., Lancia, L. (2011) On place assimilation within sibilant sequences – comparing French and English. Journal of Phonetics, 39, 429-451. doi:10.1016/j.wocn.2011.04.003
McMurray, B., Clayards, M., Tanenhaus, M.K., Aslin, R.N., (2008) Tracking the time course of phonetic cue integration during spoken word recognition. Psychonomic Bulletin and Review, 15(6), 1064-1071. doi:10.3758/PBR.15.6.1064
Learning to percieve and produce L2 vowels
Learning to perceive and produce sounds that are not part of one's native language is notoriously difficult for adults. Some research suggests that experience with phonetic variability, including multiple talkers and multiple tokens, is helpful or even necessary to improve performance. It has also been suggested that in order to properly percieve L2 vowels, learners must shift what acoustic dimensions they pay attention to, and that learners go through a series of stages. We are examining the role of variability in L2 vowel learning as well as how attention shifts to the appropriate L2 acoustic dimensions using a mix of longitudinal studies with natural exposure and training studies with targeted exposure. We examine learning in both adults and children. We hope this research will contribute to models of L2 learning as well as improve L2 teaching practices.
Kim, D., Clayards, M. & Goad, H. (2015) The acquisition of new vowel contrasts by Korean learners of English: A longitudinal study. Oral presentation at the 2015 Conference of the Korean Society of Speech Sciences. May 22-23, 2015. Chungnam National University, Daejeon, Korea
Clayards, M., Wonnacott, E. (2013, October 25) A case study of childhood L2 learning of phonological contrasts. Poster presentation at the International Conference on Multilingualism, Montreal, QC. [Poster]
Brosseau-Lapré, F., Rvachew, S., Clayards, M., Dixon, D. (2013) Stimulus variability and perceptual learning of non-native vowel categories. Applied Psycholinguistics. 34 (3), 419-441 doi:10.1017/S0142716411000750
Clayards, M., Toscano, J. (2010, August) Modeling age of exposure in L2 learning of vowel categories. Poster presented at the Annual Meeting of the Cognitive Science Society, Portland, OR. [Poster]
Plasticity across the lifespan
When percieiving speech listeners are incredibly attuned to the patterns of speech around them, rapidly shifting their perception to account for differences in dialect, accent or other talker ideosyncracies. We are interested in the mechanisms that drive this plasticity, the cognitive factors that support it, and whether and how plasticity changes as we age.
Kim, D & Clayards, M. (2016). Individual differences in the relation between perception and production and mechanisms of phonetic imitation. Oral presentation at the Korean Society of Speech Sciences 2016 Conference. May 20–21. Gwangju Institute of Science and Technology, Gwangju, Korea.
Schreiber, E., Onishi, K., Clayards, M. (2013) Manipulating phonological boundaries using distributional cues. Proceedings of Meeting on Acoustics (POMA), Vol. 19. 9 pages. doi:10.1121/1.4801082
Lindsay, S., Clayards, M., Gennari, S., Gaskell, G. (2010, September) Plasticity of phoneme categories in speech perception and production. Poster presented at Architectures and Mechanisms of Language Processing (AMLaP), York, UK. [Poster]
Clayards, M., Tanenhaus, M.K., Aslin, R.N., Jacobs, R.A., (2008) Perception of speech reflects optimal use of probabilistic speech cues. Cognition, 108(3), 804-809. doi:10.1016/j.cognition.2008.04.004.