Presentation on theme: "Today Nonlearnable production grammars: ranking reversals and reinterpretation of contrast Fijian Malayalee English Korean liquids."— Presentation transcript:
Today Nonlearnable production grammars: ranking reversals and reinterpretation of contrast Fijian Malayalee English Korean liquids
Our job in processing speech… Turn sound waves (vibration of air molecules) into meaning. To do this, we need to interpret the acoustic cues in the sound waves in order to translate sound waves into phonological representations.
From sound to meaning Acoustic Form (perception) Phonological Representation (production) Phonetic Representation
Questions When a speaker mispronounces a foreign word, is the mispronunciation due to misproduction? misperception?
Japanese example EnglishJapanese [be ɪ sb ɔ l][be:suboru]
First Possibility: Accurate Perception, Inaccurate Production Japanese listener hears [be ɪ sb ɔ l]. /be ɪ sb ɔ l/ is input to Japanese production grammar, which disallows certain segments and consonant codas. Production grammar transforms /be ɪ sb ɔ l/ to [be:suboro].
Second Possibility: Inaccurate Perception, Accurate Production Japanese listener hears [be:suboru]. /be:suboru/ is input to Japanese production grammar, and is a legal Japanese structure. Output of production grammar is [be:suboru].
Evidence for Misperception of /r-l/ Miyagawa et al. (1975) (and others): English listeners perceived /r-l/ continuum categorically; Japanese listeners did not have clear category boundaries for /r/ vs. /l/.
Effect of Native Language In English, the [r] –[l] contrast is significant: ‘rip’ vs. ‘lip’ In Japanese, this contrast is not significant: Japanese employs a single liquid pronounced more like [r] in certain contexts, more like [l] in other contexts.
Misperception even with good production Sheldon & Strange (1982): Japanese students of English who produced an English-like /r/-/l/ contrast still performed poorly on discrimination (even of their own [ra], [la] tokens).
Evidence for misperception of consonant sequences as CVC Dupoux et al. (1999): Japanese listeners did not reliably distinguish forms like [ebzo] – [ebuzo] (they heard ‘illusory vowels’). French listeners DID distinguish [ebzo]- [ebuzo].
Effect of Native Language In French (and English), the contrast between VCCV and VCVCV is significant: ‘NAFTA’ vs. ‘taffeta’ In Japanese, no such contrast exists because obstruents ([f], [b], [z], etc.) are not possible in syllable coda.
Persistent misperception Takagi & Mann (1995): adult Japanese speakers who had lived in the US and been using English daily for more than 12 years still performed below English speakers on perception tests.
Our basic question Do foreign language modification patterns come from misperception or misproduction? And how can you tell (short of doing perception experiments for each case)?
Criterion: Learnability OT provides a model of acquisition. This model allows us to determine whether a particular grammar is learnable from a set of input data.
Acquisition of a production grammar THE LEARNER’S TASK: To discover constraint rankings.
DEFAULT RANKING M >> F e.g., NoComplexOnset >> Max (don’t delete) Predicts underlying /sno/ mapped to [so].
Constraint reranking: error-driven If the learner hears a marked structure (e.g. [sno]), (s)he will rerank the constraints. Max >> NoComplexOnset
Learning Fx >> Fy In order to learn relative ranking of faithfulness constraints, learner must have evidence of unfaithful mappings.
F >> F If /sno/ > [so], then deletion is the preferred repair. Dep (don’t insert) >> Max (don’t delete) If /sno/ > [sono], then insertion is the preferred repair. Max (don’t delete) >> Dep (don’t insert)
Is a grammar learnable? Rankings must be either universal default (M>>F) or learnable from the data
Case Study 1: Fijian stop adaptation (Kenstowicz 2003) Fijian: ‘balloon’ [balun] > [ m baluni] (*[paluni])
Fijian NL (native language) grammar M >> F constraint banning fully oral stop [b] outranks faithfulness What choices do Fijians have as substitutes for [b]?
Fijian Native Language Phonemes Voiceless unaspirated /p/ Voiced prenasalized/ m b/
Why do Fijians choose /b/ > [ m b], not [p]? Modification grammar: Ident[voice] >> Ident[nasal] (maintaining voice specification is more important than maintaining nasal specification)
Where does this ranking come from? Ident[voice] >> Ident[nasal] From English? From Fijian? From universal grammar?
Alternative analysis: misperception Kenstowicz 2003: Word-initial Fijian stops are often only slightly prenasalized (or not at all prenasalized). NL perception grammar interprets word- initial voiced stop as prenasalized. (Voicing is a cue for prenasalization).
Fijian stop adaptation as NL transfer Fijian NL perception grammar interprets the English /p-b/ contrast in terms of Fijian /p- m b/ contrast.
Case Study 2: Malayalee English
Malayalee English (Mohanan & Mohanan 2003) English intervocalic voiceless stops Rippo:RT‘report’ bekkar‘baker’ pæ:kket‘packet’
Malayalam NL grammar Markedness constraint: *V[-voice]V: no voiceless stops in intervocalic position (also active in Korean) M >> F
Malayalee English grammar Ident(voice) >> Ident(length) Maintaining voicing specification is more important than maintaining length specification
Learnability problem Evidence for reranking of length faithfulness and voicing faithfulness No evidence from Malayalam No evidence from English
BUT-- The adaptation pattern is explainable as transfer of Malayalam perception grammar.
Malayalee English, continued English intervocalic voiced stops bæ:bu:n‘baboon’ iRigeet‘irrigate’ figaR‘figure’
Alternative analysis: misperception Malayalam speakers interpreted English contrast in terms of Malayalam contrast EnglishMalayalam voice contrastlength contrast VkV /VkkV/ > [VkkV] VgV /VkV/ > [VgV]
Malayalam cues for singleton- geminate contrast (Local & Simpson (1999) 1. Voicing: singletons are voiced intervocalically. 2. Vowel duration: vowels longer before singletons than before geminates mean V duration: 76.5 msec before singleton 58.8 msec before geminates
English cues for voicing contrast 1. Voicing 2. Vowel duration: vowel is longer before voiced consonant.
Note: English voice contrast is not maintained in all contexts ‘possible’ > [p ɔ :sibL] ‘impossible’ > [imb ɔ :sibL] Malayalee English ranking: *NC[-voice] >> Ident(voice)Foreign>> *V[-voice]V How could this be learned?
Interim summary Fijian and Malayalee English adaptation patterns required specific production grammar rankings. These rankings were not learnable from the data of either the native or the foreign language.
In Fijian, the adaptation rankings contradicted putative universal rankings (so they cannot be default). In Malayalee English, the adaptation rankings contradicted the NL rankings.
In both languages, the adaptation pattern could be better understood as interpretation of the foreign language acoustic cues in terms of a native language contrast.
If misproduction does stem from misperception… At what level of processing does misperception occur?
Sources of Misperception Do listeners accurately perceive the acoustic differences, but miscategorize them? OR fail to perceive acoustic differences that are relevant for native language contrasts?
Native Language Neural Commitment Hypothesis (Kuhl 2004) Early exposure to a language produces a “neural commitment” to the acoustic cues that are important for that language. This neural commitment leads to efficient processing of NL contrasts (but not of FL contrasts).
But what if you start early? Pallier et al. (1997) tested ability of fluent Spanish-Catalan bilinguals to discriminate [e] and [ ɛ ], which contrast in Catalan but not in Spanish.
Subjects included 2 groups bilinguals with Spanish as first language bilinguals with Catalan as first language Both groups used both languages daily were highly proficient in both languages had been exposed to the second language by age 6
Even for fluent bilinguals, mother tongue shaped perception Subjects whose first language exposure was to Spanish were unable to reliably perceive the e/ ɛ distinction. In contrast, subjects whose first exposure was to Catalan DID perceive this contrast.
Hypothesis Early exposure to a language makes the speech processing system sensitive (only?) to those acoustic cues that distinguish linguistically significant contrasts in the native language.
Case Study 3: Korean Pronunciation of English [r], [l]
[r] – [l] alternations in Korean tal ‘moon’ tar-i‘moon (nominative)’
/l/ and /r/ do not contrast in Korean /l/ occurs in syllable coda (word-finally and before a consonant) /r/ occurs in syllable onset (word-initially and between vowels)
Korean Liquid Alternation (Lee 2001) a. /l/ tal‘moon’ mal‘horse’ sal.ku ‘apricot’ b. /r/ ta.r-i‘moon (nom.)’ ma.r-i‘horse (nom.)’ sa.ram‘person’
How do Korean speakers interpret the English /l/ - /r/ contrast?
Possibility One: Accurate Perception, Inaccurate Production According to Korean grammar: Both /l/ and /r/ should be pronounced as /l/ in syllable coda, as /r/ in syllable onset.
Possibility One: Accurate Perception, Inaccurate Production Korean production grammar forces intervocalic [l] and [r] to be pronounced as [r] in syllable onset: ‘cherry’ heard as /ceri/ pronounced as [ce.ri]? ‘cello’ heard as /celo/ pronounced as [ce.ro]?
Possibility Two: Inaccurate Perception, Accurate Production Koreans do not perceive [r] – [l] contrast: ‘cherry’ heard as /ceri/ pronounced as [ce.ri]? ‘cello’ heard as /cero/ pronounced as [ce.ro]?
If Korean speakers simply map English phonemes to Korean phonemes… The [r] – [l] contrast should not be maintained by Korean speakers—it should be lost either in perception or in production. But what actually happens?
Korean Adaptation of English liquids (Kenstowicz 2005, Oh 2005) intervocalic /r/ > [r] k ʰ o:ras ɨ ‘chorus’ oren ʒ i‘orange’ mis ɨ t ʰ eri‘mystery’
BUT intervocalic /l/ > [ll] c ʰ ello‘cello’ sillik ʰ on‘silicon’ k ʰ olla‘cola’
Though there is some variation [kilo, killo]‘kilo’ Oh (2005): influence of spelling orthographic ‘ll’ > [ll]99.9% orthographic ‘l’ > [ll]84% So strong trend toward [ll], regardless of spelling.
Puzzle /r/ - /l/ contrast is not significant in Korean, but Koreans maintain it in English words. English [r] > Korean [r] (k ʰ o:ras ɨ ‘chorus’) English [l] > Korean [ll] (k ʰ olla ‘cola’)
But Korean has [r] – [ll] contrast Oh (2005) mu.ri‘group’mul.li‘physics’ mə.ri‘head’məl.li‘far’
English ContrastKorean Contrast /r/>/r ~ l/ /l/>/ll/ although English (initial) [r] has longer F1 transition than [l] (O’Connor et al. 1957)
Does the change from /l/ to /ll/ take place in production? Optimality Theory says it can’t.
Korean Native Language Grammar Lee (2001) [l] only if moraic (attached to coda) >> DepMora (don’t change duration) >> Ident[lateral] (don’t change laterality) (=>To repair illegal structure V[l]V, change it to V[r]V)
To get pattern in which V[l]V is repaired by changing it to V[ll]V, we would need to rerank the constraints.
Problem There is no data that would cause the learner to rerank these constraints in this way—nothing about English provides evidence that changing duration is a better way to repair an illegal structure than changing laterality.
So.. Analysis assuming accurate perception, inaccurate production is ruled out. The theory of grammar learning provides no way for learners to come up with a grammar that would transform V[l]V to V[ll]V.
Inaccurate perception? Do Korean listeners actually hear English [VlV] as [VllV]?
The relevant cues for Korean listeners: 1. presence/absence of laterality (mainly F3) 2. consonant duration muri = [-lateral, short]‘group’ mulli = [+lateral, long]‘physics’
Questions How important is duration in signalling the VrV – VllV contrast for Korean listeners? Would a difference in laterality alone be enough to signal this contrast?
Kim (2007): [lateral] alone is enough Subjects: monolingual speakers of Korean
Kim (2007) Stimuli 1. Real words containing VllV, e.g. [mulli] (legal in Korean). 2. Real words containing VrV, e.g. [muri] (legal in Korean). 3. ‘Words’ containing VlV, e.g. [muli] (illegal in Korean), made by shortening the [l] in V[ll]V words.
Kim (2007) Task Listeners heard (edited) words like [muli]. Forced choice: Did you hear [muri] (‘group’) or [mulli] (‘physics’)?
Results [VlV] heard as [VllV]32490% [VrV] 3610%
Kim (2007) results suggest that Korean listeners pay at least as much attention to the laterality as to consonant duration. Laterality alone is enough to cause Korean listeners to classify even a short [l] as [ll].
BUT Does this mean that Korean listeners actually do not hear the differences between English [l] and Korean [ll]?
ERP Event-Related Potentials: A non-invasive method of measuring electrical activity in the brain during low level processing (Luck 2005).
Mismatch Negativity The Mismatch Negativity (MMN) indicates brain response to change in an auditory stimulus. MMN is elicited even in the absence of attention to stimulus (e.g., while watching a silent movie).
Oddball Paradigm ba - ba - ba - ba - pa standard deviant MMN is typically elicited msec after onset of deviance.
Discrimination tasks tap into conscious categorization. ERP taps into involuntary, pre-attentive brain reactions to change in auditory stimuli.
MMN and Contrast Various experiments have shown much stronger MMN to acoustic differences that cross NL phoneme boundaries.
Phillips et al MEG investigation of stimuli varying on [tæ-dæ] continuum. English listeners responded differently when standard/deviant boundary crossed [t-d] phoneme boundary than when it fell within a category, though degree of acoustic variation was the same.
Stronger MMN/MMF with NL contrast Japanese, French: [ebzo] vs. [ebuzo] (Dehaene-Lambertz et. al. 2000) Japanese, English: [ra] vs. [la] (Zhang et. al. 2003) Hungarian, Finnish: [æ] vs. [e] (Winkler et. al. 1999) Hindi, English: [pa] vs. [ba] (Sharma and Dorman 2000)
Hwang, Broselow, Squires tested Korean responses to 1. enne vs. ene (possible NL contrast) [kannan] ‘newborn’ vs. [kanan] ‘poverty’ 2. elle vs. ele (not a possible NL contrast, because *[ele] is illegal) Supported by NSF grant BCS
Subjects 10 native speakers of Korean, now students at SUNY Stony Brook, in US 6months – 3 years All proficient speakers of English
Task Subjects watched a silent movie. Subjects heard through headphones: enne – enne - enne- enne- ene – enne… or elle – elle – elle – elle – ele – elle – elle … (8 blocks of 300 trials = 2400 trials) onset of deviance: 88ms.
Same acoustic difference Both the [ene] and [ele] stimuli were created by shortening the duration of the long consonants in [enne], [elle]. Exactly the SAME durational change for [enne]=[elle]98ms. [ene]= [ele]48ms.
Same acoustic difference, but different MMN responses (preliminary results) Change from [enne] to [ene]: Stronger MMN Change from [elle] to [ele]: Weaker MMN STRONGER MMN RESPONSE to the cross-category change ([enne] – [ene]) than to the within-category change ([elle]- [ele]).
Standard Deviant ele ene Grand Average of responses to Standards and Deviants
Black line: response to ele after ele, or ene after ene Red line: response to ele after elle, or ene after enne
Standard Deviant ele ene Grand Average of responses to Standards and Deviants
MMN Grand Difference Wave (Deviant-Standard) Ele Ene
Shows difference in response to elle- ele change vs. enne-ene change.
MMN Ele Ene Grand Difference Wave (Deviant-Standard)
Ele Ene Grand Difference Wave (Deviant-Standard) 250ms ele ene
Our original question: Why VrV > VrV, but VlV > VllV? k ʰ o:ras ɨ ‘chorus’ k ʰ olla‘cola’
Inaccurate Perception: Why Korean listeners interpret ‘cola’ as [kolla] Korean listeners hear laterality of ‘cola’. This is a stronger cue than durational cue—in Korean, any lateral segment between vowels must be long.
Mishearing in early processing? ERP data suggests Korean speakers’ brains respond less strongly to the durational difference in [ele] vs. [elle] than in [ene] vs. [enne]. Native Language Neural Commitment Hypothesis (Kuhl 2004).
Implications for Foreign Language Teaching If students can’t even hear some of the FL contrasts, will perception training help them?
It’s not all bad news Dehaene-Lambertz et al. (2000): at later time windows (where conscious processing may be involved), Japanese speakers responded to ebzo-ebuzo contrast more like French speakers.
It’s not all bad news Tremblay et al. (1997): training DID improve MMN response to non-native contrast. But problems do persist, at least for some non-native contrasts.
Interim Summary Formal phonology tells you which production grammar patterns are learnable. 3 unlearnable patterns (in Fijian, Malayalee English, Korean) result from transfer of perception grammar—foreign language acoustic cues are interpreted in terms of NL contrasts.
This misperception seems to occur at early levels of processing, and to persist even after extensive exposure to foreign language. However, listeners may be able to overcome this at higher levels of processing.