modelling the perceptual development of phonological contrasts with ot and gradual learning...
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Modelling the perceptual development of phonological contrasts with OT and Gradual Learning Algorithm. Paola Escudero, University of Reading [email protected] Paul Boersma, University of Amsterdam [email protected] 25 th Penn Linguistics Colloquium March 3, 2001. - PowerPoint PPT PresentationTRANSCRIPT
Modelling the perceptual developmentof phonological contrasts with
OT and Gradual Learning Algorithm
Paola Escudero, University of [email protected]
Paul Boersma, University of [email protected]
25th Penn Linguistics ColloquiumMarch 3, 2001
Sound contrasts
Sound contrasts and acoustic information An example of a sound contrast
What are the acoustic differences between the two?
Two acoustic cues to“ship” vs. “sheep”
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50050 75 100 125 150 175
Duration (ms)
Elspeth’s production environment(Scottish English)
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Duration (ms)
ship
sheep
lid
lead
filling
feeling
Snicker
sneaker
Liz’s production environment(Southern English)
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50050 75 100 125 150 175
Duration (ms)
ship
sheep
lid
lead
filling
feeling
Snicker sneaker
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440
48060 72 84 96 108 120
Duration (ms)
/I/
/i//I/
/i/
Elspeth’s and Liz’saverage production environments
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Duration (ms)
?
/I/
/i//I/
/i/
Do Elspeth and Liz perceive [350 Hz, 80 ms] as “ship” or as “sheep”?
Liz Elspeth
Why using the nearest production prototype in perception?
Answer: “likelihood maximisation”:choose the most likely produced category,given a certain F1 & duration
Functional principle: “minimise the probability of perceptual confusion”
How Elspeth and Liz perceive the segments reliably
[350 Hz,80 ms]
350 Hznot /I/
80 msnot /i/
80 msnot /I/
350 Hznot /i/
/I/ *! * /i/ * *
[350 Hz,80 ms]
350 Hznot /i/
80 msnot /i/
80 msnot /I/
350 Hznot /I/
/I/ * */i/ *! *
60 72 84 96 108 120
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Duration (ms)
Baby Elspeth or baby LizSpectral reliance 0.5%, duration reliance -0.3%
First stage of babies Elspeth and Liz
How baby Elspeth learns Little Elspeth makes a mistake
when categorising [350 Hz, 80 ms]
[350 Hz,80 ms]
350 Hznot /i/
80 msnot /i/
80 msnot /I/
350 Hznot /I/
/I/ * *
/i/ *! *
How little Elspeth learns to perceive“ship” and “sheep” reliably (1)
60 72 84 96 108 120
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Duration (ms)
Elspeth after one monthSpectral reliance 80.9%, duration reliance 12.2%
How little Elspeth learns to perceive“ship” and “sheep” reliably (2)
60 72 84 96 108 120
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Duration (ms)
Elspeth after 2 monthsSpectral reliance 96.9%, duration reliance 9.3%
How little Elspeth learns to perceive“ship” and “sheep” reliably (3)
60 72 84 96 108 120
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Duration (ms)
Elspeth after 4 monthsSpectral reliance 96.4%, duration reliance 0.4%
How little Elspeth learns to perceive“ship” and “sheep” reliably (4)
60 72 84 96 108 120
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Duration (ms)
Elspeth after 10 monthsSpectral reliance 98.6%, duration reliance 15.7%
How little Elspeth learns to perceive“ship” and “sheep” reliably (5)
60 72 84 96 108 120
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Duration (ms)
Elspeth after 100 monthsSpectral reliance 97.8%, duration reliance 6.3%
How little Elspeth learns to perceive“ship” and “sheep” reliably (6)
60 72 84 96 108 120
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Duration (ms)
Elspeth after 1000 monthsSpectral reliance 97.1%, duration reliance 6.5%
How little Liz learns to perceive “ship” and “sheep” reliably (1)
60 72 84 96 108 120
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Duration (ms)
Liz after one monthSpectral reliance 34.6%, duration reliance 39.7%
How little Liz learns to perceive “ship” and “sheep” reliably (2)
60 72 84 96 108 120
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Duration (ms)
Liz after 2 monthsSpectral reliance 37.1%, duration reliance 55.2%
How little Liz learns to perceive “ship” and “sheep” reliably (3)
60 72 84 96 108 120
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Duration (ms)
Liz after 4 monthsSpectral reliance 53.5%, duration reliance 52.7%
How little Liz learns to perceive “ship” and “sheep” reliably (4)
60 72 84 96 108 120
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Duration (ms)
Liz after 10 monthsSpectral reliance 46.3%, duration reliance 85.0%
How little Liz learns to perceive “ship” and “sheep” reliably (5)
60 72 84 96 108 120
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Duration (ms)
Liz after 100 monthsSpectral reliance 51.9%, duration reliance 56.6%
How little Liz learns to perceive “ship” and “sheep” reliably (6)
60 72 84 96 108 120
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Duration (ms)
Liz after 1000 monthsSpectral reliance 54.0%, duration reliance 51.4%
The perception of real adult Elspeth and Liz
4.49 4.09
ScottishAverage
reliance 11%, weight 10%
[i]
[I]
[i:]
[I:]
5.23.71
SouthernAverage
reliance 32%, weight 30%
[i]
[I]
[i:]
[I:]
What about L1-Spanish Isabel, who moves to Scotland and then
to Southern England?
Isabel’s production environment (Spanish)
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Duration (ms)
/i/
/e/
Isabel’s adult perception (Spanish)
60 72 84 96 108 120
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Duration (ms)
Isabel after 20 years in PeruSpectral reliance 99.9%, duration reliance 2.2%
Isabel’s new production environment (Scottish English)
I FA
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48060 72 84 96 108 120
Duration (ms)
/I/
/i/
How Isabel learns to perceive“ship” and “sheep”
60 72 84 96 108 120
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Duration (ms)
Isabel after 10 years in EdinburghSpectral reliance 98.8%, duration reliance 4.4%
Isabel’s new production environment (Southern English)
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Duration (ms)
/I/
/i/
How Isabel learns to perceive“ship” and “sheep”
60 72 84 96 108 120
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Duration (ms)
Isabel after 10 years in LondonSpectral reliance 69.3%, duration reliance 44.5%
Three types of real L2 categorisation
5.29
3.5abg
reliance 40%, weight 46%
[i]
[I]
[i:]
[I:] 3.4
3.29af
reliance 87%, weight 88%
[i]
[I]
[i:]
[I:]
4.4 4.8
mt
reliance -10%
[i]
[I]
[i:]
[I:]
4.38 4.67
mf
reliance -6%
[i]
[I]
[i:]
[I:]
6.5
2.5
1.92jg
reliance 37%, weight 33%
[i]
[I]
[i:]
[I:] 4.25
4.75ef
reliance 86%
[i]
[I]
[i:]
[I:]
Spectral reliance only Duration reliance onlyCue integration
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!