Cours 03

Sharon

Description

Word segmentation…l e p e t i ch i en m o r s e r a en t é r é d e m ainle pe ti chien mor se ra en té ré de mainle petit chien mort sera enterré demain0 2.1Recall• Finnish vowels:front backi y ue Ø oorthography: ö = /Ø/æ aä = /æ/‘vowel harmony’: within words, /y,Ø,æ/ cannot co-occur with /u,o,a/ (/i,e/ can occur with both /y,Ø,æ/ and /u,o,a/)• Finnish stress: all words have initial stressWord segmentation strategies• transitional probabilities• phonotactic cues• allophonic cues• prosodic boundaries Where do fixed stress and vowel harmony fit in?Word stress versus vowel harmony• word stress:– in principle, 100% reliable: every Finnish word starts with a stressed syllable– in practice, much less reliable: in running speech, not every stressed syllable is realized with clear acoustic stress cues (F0 and energy), and these same cues have other functions than signaling stress (intonation, emotion, phrase boundaries,…)Word stress versus vowel harmony• vowel harmony:– in principle, not 100% reliable:• disharmonic sequences signal word boundaries (except in some compounds and loanwords, e.g. ‘analyysi’), but the reverse does not hold (harmonic sequences are found both within and across words)– in running speech, however, very few exceptions to what is expected in principle• front and back vowels are reliably articulated as front and back, respectively!Vroomen et al. 1998• Word spotting: detect disyllabic words embedded at the end ...

Informations

• Publié par: Nezog
• Nombre de lectures: 27
• Langue: English

Extrait

l e

le

le

p e

pe

t

ti

petit

i

Word segmentation

ch i en m

chien

chien

o

mor

mort

r

s e r a en t é r é d e

se ra en té ré de

sera

enterré

m

ain

main

demain

…

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Finnish vowels: front back i y u eØo æa

Recall

orthography: ö = /Ø/ ä = /æ/

‘vowel harmony’: within words, /y,Ø,æ/ cannot co- occur with /u,o,a/ (/i,e/ can occur with both /y,Ø,æ/ and /u,o,a/)

Finnish stress: all words have initial stress

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Word segmentation strategies

transitional probabilities

phonotactic cues

allophonic cues

prosodic boundaries

Where do fixed stress and vowel harmony fit in?

•

Word stress versus vowelharmony

word stress: –in principle, 100% reliable: every Finnish word starts  with a stressed syllable – in practice, much less reliable: in running speech, not every stressed syllable is realized with clear acoustic stress cues (F0 and energy), and these same cues have other functions than signaling stress (intonation, emotion, phrase boundaries,…)

•

Word stress versus vowelharmony

vowel harmony: – in principle, not 100% reliable: • disharmonic sequences signal word boundaries (except in some compounds and loanwords, e.g. ‘analyysi’) , but the reverse does not hold (harmonic sequences are found both within and across words) – in running speech, however, very few exceptions to what is expected in principle • front and back vowels are reliably articulated as front and back, respectively!

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Vroomen et al. 1998

Word spotting: detect disyllabic words embedded at the end of trisyllabic non-words

Exp. 1 – cue: vowel harmony only • disharmonic vs. harmonic context • no stress on embedded word • ex.: detectHYmyinPUhymyvs.PYhymy – results: • better performance forPUhymythan forPYhymy

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Vroomen et al. 1998

Word spotting: detect disyllabic words embedded at the end of trisyllabic non-words

Exp. 2 – vowel harmony + stress • disharmonic vs. harmonic context • stress on initial syllable of disyllabic word • ex.: detectHYmyinpuHYmyvs.pyHYmy – results: • marginally better performance forpuHYmy thanandpyHYmy • overall better performance in this experiment than in the previous one

Exp. 3: artificial language learning • four artificial languages, each containing 6 CVCVCV ‘words’

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no stress

initial stress

harmonious motamu

'motamu

disharmonious motamy

'motamy

each language consists of random concatenation of the 6 words produced by a speech synthesizer – no pauses between words – all syllables have equal length – in stress languages: raised F0 on initial syllable

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Exp. 3: artificial language learning

Finnish and French participants background assumption: listeners use their native language segmentation strategies –Finnish: initial stress, harmony –French: final stress, no harmony each participant exposed to one of the four languages – length of exposure: 10 minutes (each word appears 150 times) test: forced choice (word versus non-word)

100

80 60

40

20

0

*

*

Finnish

Results

Finnish - all groups better than chance - main effect of stress - marginal stress-harmony interaction - no-stress condition: effect of harmony

French

no stress harmonious no stress disharmonious initial stress harmonious initial stress disharmonious

French - all groups better than chance - no main effects or interaction

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Extra discussion

(no tin Vrooemnet al.)

How did the French manage to perform better than chance? – suppose they – incorrectly – inferred the presence of a word boundaryaftereach stressed syllable: shouldn’t they be worse than chance? – this incorrect strategy raises the number of words from 6 to 30 (can you show this?)impossible to learn within 10 minutes – French subjects probably relied on transitional probabilities