1. Optimality-Theoretic modelling of phoneme split Paul Boersma, University of Amsterdam Paola Escudero, McGill University EuroSLA 11, Paderborn September 26, 2001

2. Six hypotheses about phonemic contrasts ¿ Their production is dialect-dependent. ¿ Their perception is dialect-dependent. ¿ L1 learners achieve optimal perception given their production environment. ¿ This can be modelled by Optimality Theory and the Gradual Learning Algorithm. ¿ L2 learners do not necessarily achieve optimal perception. ¿ This can also be modelled by OT & GLA.

3. We test these six hypotheses on the English /I/-/i/ contrast L1: Scottish Standard English L1: Southern English Standard English L2: Spanish-speaking learners of English

4. Adult native Scottish production

5. Adult native Southern production

6. Six hypotheses about phonemic contrasts  Their production is dialect-dependent. ¿ Their perception is dialect-dependent. ¿ L1 learners achieve optimal perception. ¿ This can be modelled by OT & GLA. ¿ L2 learners do not necessarily achieve optimal perception. ¿ This can also be modelled by OT & GLA.

7. Adult native perception Scottish Southern

8. Six hypotheses about phonemic contrasts  Their production is dialect-dependent.  Their perception is dialect-dependent. ¿ L1 learners achieve optimal perception. ¿ This can be modelled by OT & GLA. ¿ L2 learners do not necessarily achieve optimal perception. ¿ This can also be modelled by OT & GLA.

9. Why does perception have to depend on the production environment?  Answer: to optimise perception, the listener has to minimise the probability of perceptual confusion  The optimal perception strategy, therefore, is: likelihood maximisation, i.e. choose the most likely produced category, given a certain F1 & duration

10. Average production environment: Optimal perception (max. likelihood): 87.1% 82.5% Scottish Southern

11. Six hypotheses about phonemic contrasts  Their production is dialect-dependent.  Their perception is dialect-dependent.  L1 learners achieve optimal perception (they integrate the two acoustic cues). ¿ This can be modelled by OT & GLA. ¿ L2 learners do not necessarily achieve optimal perception. ¿ This can also be modelled by OT & GLA.

12. Native English constraint set “260 Hz should not be perceived as /I/” “260 Hz should not be perceived as /i/” “500 Hz should not be perceived as /I/” “500 Hz should not be perceived as /i/” “60 ms should not be perceived as /I/” “60 ms should not be perceived as /i/” “180 ms should not be perceived as /I/” “180 ms should not be perceived as /i/” …and so on, for all F1 and duration values

13. Average production environment: Optimal perception (max. likelihood): 87.1% 82.5% Scottish Southern

14. Scottish optimal perception in OT [349 Hz, 74 ms] 349 Hz not / I / 74 ms not / i / 74 ms not / I / 349 Hz not / i / /I/ /I/ *!* /i//i/ ** [349 Hz, 74 ms] 349 Hz not / i / 74 ms not / i / 74 ms not / I / 349 Hz not / I / /I//I/ ** /i/ /i/ *!* Southern optimal perception in OT

15. How is the knowledge acquired?  Whenever the listener makes a categorization error, she applies a Gradual Learning Algorithm: [349 Hz, 74 ms] 349 Hz not / i / 74 ms not / i / 74 ms not / I / 349 Hz not / I / /I//I/ ** ** /i//i/ *!  **

16. Simulated Scottish L1 development baby 4 months 1000 months 50.0% 85.3% 87.0% (optimal: 87.1%)

17. Simulated Southern L1 development baby 4 months 1000 months 50.0% 79.7% 82.5% (optimal: 82.5%)

18. Six hypotheses about phonemic contrasts  Their production is dialect-dependent.  Their perception is dialect-dependent.  L1 learners achieve optimal perception.  This can be modelled by OT & GLA. ¿ L2 learners do not necessarily achieve optimal perception. ¿ This can also be modelled by OT & GLA.

19. Typical L2 categorization by Spanish learners of English ScotlandSouthern England

20. Six hypotheses about phonemic contrasts  Their production is dialect-dependent.  Their perception is dialect-dependent.  L1 learners achieve optimal perception.  This can be modelled by OT & GLA.  L2 learners do not necessarily achieve optimal perception. ¿ This can also be modelled by OT & GLA.

21. Native Spanish constraint set “260 Hz should not be perceived as /i/” “260 Hz should not be perceived as /e/” “260 Hz should not be perceived as /a/” “260 Hz should not be perceived as /o/” “260 Hz should not be perceived as /u/” low ranked or non-existent: “60 ms should not be perceived as /i/” “60 ms should not be perceived as /e/” “60 ms should not be perceived as /a/” “60 ms should not be perceived as /o/” “60 ms should not be perceived as /u/” …and so on, for all F1 and duration values

22. Constraint set of Spanish learners of English “260 Hz should not be perceived as /i/” “260 Hz should not be perceived as /e/” “260 Hz should not be perceived as /a/” “260 Hz should not be perceived as /o/” “260 Hz should not be perceived as /u/” “60 ms should not be perceived as /short/” “60 ms should not be perceived as /long/” …and so on, for all F1 and duration values, but: no F1-to-/length/ mappings; no duration-to-/vowel quality/ mappings.

23. Strategy of a Spaniard in Scotland Two-category assimilation: English /i/  L2 /i/ English / I /  L2 /e/

24. Simulation of a Spaniard in Scotland 200 months 204 months 1000 months 74.9% 83.5% 87.2% (optimal: 87.1%)

25. Strategy of a Spaniard in S.England New length contrast: English /i/  L2 /i:/ English / I /  L2 /i/

26. Simulation of a Spaniard in S.England 200 months 204 months 1000 months 50.0% 79.0% 79.3% (optimal: 82.5%)

27. Six hypotheses, now finally confirmed by us, about phonemic contrasts  Their production is dialect-dependent.  Their perception is dialect-dependent.  L1 learners achieve optimal perception.  This can be modelled by OT & GLA.  L2 learners do not necessarily achieve optimal perception.  This can also be modelled by OT & GLA.

28. Native S.English has 12 arbitrary symbols: A possible assimilation pattern Spanish S.English has 2x5 vowels (7 symbols): I — i i — ii — i ,  — A E — e  — o U — u e — ee — e a — aa — a o — oo — o u — uu — u

29. Discussion  GLA generally leads to optimal perception, but it depends on the appropriateness of the constraint set.  L2 learners seem to have constraint sets that are too restricted for the new language environment.  The restricted constraint set does not seem to cause the L2 learner much harm.  Adding a new contrast on the basis of duration seems to be easier than splitting existing vowel quality categories.

30. Thank you for your attention!