modelling the perceptual development of phonological contrasts with ot and the gla
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Modelling the perceptual development of phonological contrasts with OT and the GLA. Paola Escudero [email protected] Paul Boersma [email protected] Utrecht Institute of Linguistics May 14 2001. Introduction. The Language Acquisition task - PowerPoint PPT PresentationTRANSCRIPT
Modelling the perceptual developmentof phonological contrasts with
OT and the GLA
Paola [email protected]
Paul [email protected]
Utrecht Institute of Linguistics May 14 2001
Introduction The Language Acquisition task The task in Phonological Acquisition
– Mapping from acoustic input to discrete categories– E.g.
Overview of the talk– /I/ vs. /i/ in two English varieties– Modelling perception and its acquisition– Comparison with real listeners
Elspeth’s production environment(Scottish English)
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Liz’s production environment(Southern English)
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Elspeth’s and Liz’saverage production environments
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/I/
/i//I//i/
Do Elspeth and Liz perceive [349 Hz, 74 ms] as “ship” or as “sheep”?
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?
/I/
/i//I//i/
Why does perception have to depend on the production environment?
Answer: to optimise perception, the listener has tominimise the probability ofperceptual confusion
The optimal perception strategy, therefore, is:likelihood maximisation, i.e.choose the most likely produced category,given a certain F1 & duration
Maximum likelihood strategy
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/i/?
/I/
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/i/
/I/ ?
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The knowledge underlying Elspeth’s and Liz’ optimal perception
[349 Hz,74 ms]
349 Hznot //
74 msnot //
74 msnot //
349 Hznot //
// *! * // * *
[349 Hz,74 ms]
349 Hznot //
74 msnot //
74 msnot //
349 Hznot //
// * * //
*! *
Initial stage of babies Elspeth and Liz
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dur.rel. 0.7%
How is the knowledge acquired? Answer: Little Elspeth learns by
applying the GLA whenever she makes a categorisation error
[349 Hz,74 ms]
349 Hznot //
74 msnot //
74 msnot //
349 Hznot //
// * *
// *! *
How little Elspeth learns to perceive“ship” and “sheep” reliably (1)
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dur.rel. 0.5%1 month
How little Elspeth learns to perceive“ship” and “sheep” reliably (2)
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dur.rel. 9.6%2 months
How little Elspeth learns to perceive“ship” and “sheep” reliably (3)
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dur.rel. 13.8%4 months
How little Elspeth learns to perceive“ship” and “sheep” reliably (4)
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dur.rel. 11.2%10 months
How little Elspeth learns to perceive“ship” and “sheep” reliably (5)
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dur.rel. 4.5%100 months
How little Elspeth learns to perceive“ship” and “sheep” reliably (6)
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dur.rel. 8.4%1000 months
How little Liz learns to perceive “ship” and “sheep” reliably (1)
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dur.rel. 57.9%1 month
How little Liz learns to perceive “ship” and “sheep” reliably (2)
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dur.rel. 76.6%2 months
How little Liz learns to perceive “ship” and “sheep” reliably (3)
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dur.rel. 48.3%4 months
How little Liz learns to perceive “ship” and “sheep” reliably (4)
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dur.rel. 57.7%10 months
How little Liz learns to perceive “ship” and “sheep” reliably (5)
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dur.rel. 74.2%100 months
How little Liz learns to perceive “ship” and “sheep” reliably (6)
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dur.rel. 68.2%1000 months
Real vs. Simulated listeners
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dur.rel. 8.4%260300
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dur.rel. 68.2%
Scottishdur.rel. 10.6%
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Southerndur.rel. 34.6%
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What about L1-Spanish Isabel, who moves to Scotland and then
to Southern England?
Isabel’s production environment (Spanish)
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/i/
/e/
Isabel’s adult perception (Spanish)
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dur.rel. -0.8%200 months
Isabel’s new production environment (Scottish English)
I FA
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/I/
/i/
How Isabel learns to perceive“ship” and “sheep”
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dur.rel. 9.2%300 months
Isabel’s new production environment (Southern English)
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/I//i/
How Isabel learns to perceive“ship” and “sheep”
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dur.rel. 64.8%400 months
Three types of real L2 categorisation
Spectral reliance only Duration reliance onlyCue integration
mfdur.rel. -5.7%
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mtdur.rel. -10.0%
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abgdur.rel. 40.0%
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efdur.rel. 85.7%
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ofdur.rel. 98.6%
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ljdur.rel. 70.0%
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Summary For our perception model, we assumed:1) Perception is handled by an OT grammar 2) Its acquisition is handled by the GLA3) L2 learners start by copying their L1 grammar
With these assumptions, we can model:1) L1 Scottish and Southern English2) L2 Scottish and Southern English, partially
Conclusion Cue reliance depends on cue reliability, or
a) Differences in the production environment account for differences in perception.
b) Changes in the production environment lead to changes in perception.
The functional principle underlying this production-perception dependence is “minimisation of perceptual confusion”.
This functional principle follows from our formal modelling of the perception grammar.
Thank you for your attention!