A Study of Speech Perception: The Psychological Reality of the Obligatory Contour Principle Julie Langevin Communication Sciences and Disorders Faculty Mentor: Timothy Bryant What is the Obligatory Contour Principle? A linguistic constraint first developed by Leben (1973) to account for tones in languages – It was extended to accommodate grammatical factors by McCarthy 1988. Is a part of our phonological grammar Shapes the linguistic performance of English listeners Speech Language Triangle Perception Lexicon Production Purpose of the Study The study was done to replicate the work done by Coetzee, 2001 and to demonstrate that: • There is a phonological grammar (phonotactics) • The OCP has ‘psychological reality’ (i.e. influences how words are pronounced and is thus an inherent part of a phonological grammar) for English speakers. Specific Research Questions Does the OCP influence English speakers acceptability of nonsense words? Prediction: OCP factors do influence production: thus perception plays a role in shaping English words English makes a distinction for coronal place /t/ Continuum Construction Three stimulus sets of two continua each were constructed. Each continuum had a range of tokens ambiguous between two ‘words’. The stimulus sets are shown below: Continua from [K]~[P] [P]~[T] [K]~[T] [sKaK] to [sKaP] [sPaP] to [sPaK] [sTuT]~[sTuP] [sPuP]~[sPuT] [sKeK]~[sKeT] [sTeT]~[sTeK] Construction of the Experiment Each non-word was recorded in the carrier sentence, John said ____again to me. Using an audio program each token word was spliced so that either 40% or 60% of the vowel was cut out. Filler items were included for each of the continuums Each continuum was presented independently over the course of 2 trials Experimentation Setting-The setting for the experiment took place in a small, quite lab room. Each participant listened to the experiment through noise reduction headphones and pressed a button on the computer key board indicating the final consonant that they heard Subjects- Subjects for this experiment were 40 undergraduate native speakers of English from the University of New Hampshire. [P]~[K] Continuum [sKaP] to [sKaK] continuum [P]~[K] Bias Towards Prediction 100 80 60 [sKaP] to [sKaK] p Bias will be towards [p] because [skak] goes against OCP picked p 40 picked k 20 0 P Bias [sPaP] to [sPaK] k Bias will be towards [k] because [spap] goes against OCP [sPaP] to [sPaK] continuum 100 80 60 picked p 40 picked k 20 0 K Bias [P]~[T] Continuum [sPuT] to [sPuP] continuum 100 [P]~[T] Bias Prediction Towards 80 60 picked t 40 [sPuT] to [sPuP] t Bias will be towards [t] because [spup] goes against OCP picked p 20 0 T Bias [sTuT] to [sTuP] continuum [sTuT] to [sTuP] p Bias is uncertain because both [stup] and [stut] follow the OCP 100 80 60 picked t 40 picked p 20 0 P Bias [K]~[T] Continuum [sKeT] to [sKeK] continuum [K]~[T] Bias Towards Prediction 100 80 60 [sKeT] to [sKeK] [sTeT] to [sTeK] t k Bias will be towards [t] because [skek] goes against the OCP. Bias is uncertain because both [stek] and [stet] follow the OCP picked t 40 picked k 20 0 T Bias [sTeT] to [sTeK] continuum 100 80 60 picked t 40 picked k 20 0 K Bias Discussion Our results do support the earlier work done by Coetzee (2001). There does appear to be categorical speech recognition of nonsense words. Thus, like Coetzee we conclude that the OCP does play a role in speech production. Implications A growing body of work (e.g. Guy & Boberg 1997; Bybee, 2000, 2004) have all shown that the OCP can account for variable output data. This converging evidence suggests that gradience has to be accommodated for within formal theories of Phonology. Clinical Implications: When assessing the linguistic competence of individuals, clinicians must consider the role perception plays in word learning. Acquisition work must take perception into account normal word learning Acknowledgements The Hamel Center for Undergraduate Research whose financial support made this research possible Thanks to my faculty mentor, Professor Bryant for his guidance and support. References Alan Prince & Paul Smolensky (1993): Optimality Theory: Constraint Interaction in Generative Grammar. Rutgers University Center for Cognitive Science Technical Report 2. Bleile, Ken., (2004). Manual of Articulation and Phonological Disorders: Infancy Through Adulthood 2d ed. Clifton Park, NY: Thompson/Delmar Learning, Coetzee, A. W., (2003). In Prosodies. Selected papers from the Phonetics and Phonologicy in Iberia Conference, 2003. Sonia Frota, Marina Vigario and Maria Jolio Freitas, eds. New York: Mouton de Gruyter. Leben, W., (1978). The representation of tone. In Tone: A Linguistic Survey. Victoria Fromkin (ed.), 177-219. New York Academic Press. McCarthy, John J. (1986). OCP Effects: Gemination and antigemination. Linguistic Inquiry 17:207-263 Presentation (2008). Neurobehavioral Systems. <http://www.neurobs.com/nbs_online> Questions?