VOT trumps other measures in predicting Korean children’s early mastery of tense stops Eun Jong...
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Transcript of VOT trumps other measures in predicting Korean children’s early mastery of tense stops Eun Jong...
VOT trumps other measures in predicting Korean children’s
early mastery of tense stops
Eun Jong Kong Mary E. Beckman
Jan Edwards
LSA2010 January 7th ~ 10th
Introduction
Three-way laryngeal contrast in Korean stops• lax /p, t, k/ vs. tense /p’, t’, k’/ vs. aspirated /ph, th, kh/
e.g., /tal/ moon vs. /t’al/ daughter vs. /thal/ mask
Mastery pattern of Korean stops:• Transcription-based studies (Kim, Y, 1996; Kim &
Pae, 2005; Kim, M, 2008) described: • All (lax, tense and asp.) were mastered before three
years. • Tense stops appeared first in youngest children’s
productions. (before 2;6)
• Early mastery of tense stops:• Is this predictable based on the acoustic property of
Korean stops? • Cross-lingusitically exceptional or not?
Burst Voicing OnsetTime (s)
121.2 121.30
5000
Fre
quen
cy (
Hz)
Short lag VOT
Time (s)15.13 15.380
5000
Fre
quen
cy (
Hz)
Lead VOT
BurstVoicing Onset Burst Voicing Onset
[do'mata] tomato toastdonut
VOT = Burst – Voicing Onset
• Voice Onset Time (VOT: Lisker and Abramson 1964) and stop voicing/ aspiration contrast across languages
Early mastery of tense stops: Is this predictable?
Long lag VOT
Time (s)0 0.2006
0
9000
Fre
quen
cy (
Hz)
Language Lead Short lag Long lag
English (Macken & Barton 1980a) voiced voiced voiceless
Spanish (Macken & Barton 1980b) voiced voiceless
Cantonese (Clumeck et al 1981 ) unaspirated aspirated
Thai (Gandour et al 1986) voiced unaspirated aspirated
Long lag
Lead[t] [th] [d]
Short lag
Universal order of mastery and VOT
The category with short lag VOT is mastered first: • the least precise articulation (Kewley-Port and Preston 1974).
is achieved by the glottis opening at any time during the oral occlusion: easy to produce!
Short lag VOT of Korean tense stops
Lead
Short lag
Long lag
tense lax, aspirated
short lag
Long lag
is achieved by the laryngeal muscle tenseness that delays voicing onset until the oral release.
Korean tense stops: • short lag VOT• creaky voice quality (H1-H2)• high fundamental frequency (F0):
associated with H-tone accentual phrase in Seoul Korean (Cho, Jun and Ladefoged, 2002; Kagaya, 1974; Hardcastle 1974; Jun 1993).
When we take a closer look at Korean tense stops …
• VOT values of Korean tense stops predicts the early mastery.
At first glance…
Multiple acoustic cues of Korean stops
Multiplicity of acoustic cues suggests:
• VOT cannot be the only predictor of Korean stop mastery order.
• The relative role of other cues must also be considered.
• We need a more sensitive quantitative model of the role of VOT in relation to F0 and H1-H2 in explaining the observed order in the transcription-based study:
Goal of the study
• This study explores the relationship between native speaker transcriptions of children’s stop productions and the three acoustic characteristics (VOT, F0, H1-H2).
• Mixed effects logistic regression models– Analysis (1): children’s productions
transcribed accuracy as a function of age– Analysis (2): adults’ stop productions
target category as a function of VOT, F0 and H1-H2– Analysis (3): children’s stop productions
transcribed category as a function of VOT, F0 and H1-H2
Database
• Materials- word-initial coronal and dorsal stops embedded in real words - following vowel contexts varied among /i, a, u/.
• Participants- 70 Korean-speaking children (aged 24 to 72 months)- 20 adults (10 males and 10 females: aged 18-30 years)- recruited and recorded at Seoul, Korea.
• TaskA picture-prompted auditory word-repetition task
9/t’al.gi/ strawberry
10/ta.ram.dʒwi/ squirrel
11/th a.dʒo/ ostrich
• Accuracy judgment measures: – native speaker transcriptions of ‘correct’ or
‘incorrect’ in children’s stop productions.
• Acoustic measures: – All plosive productions also were acoustically analyzed to
measure VOT, F0 and H1-H2 (voice quality measure).
Analysis measures
burst voice onset
VOT (sec.)
Time (s)141.9 142.1
-0.06935
0.08031
0
141.871398 142.072843torn4_20000
freq
uen
cy (
Hz)
H1-H2 (dB)
first harmonic (H1)
second harmonic (H2)
frequency (Hz)
am
pli
tud
e (
dB
)
20ms
F0 = 1/interval
Results- Analysis(1): transcribed accuracy ~ age
• a trend of more tense substitutions in the younger children’s productions.
• the highest transcribed accuracy for the tense stops in the youngest.
•VOT: short lag VOT for tense stops
Results – Analysis 2: Acoustic characteristicsadults’ stops:
short lag
short lag
VOT F0 H1-H2
•F0: lower F0 for lax stops•H1-H2: lower H1-H2 for tense stops
• β1, β2, and β3 (coefficients)
: the absolute value of coefficient is the relative contribution of each predictor in determining the dependent variable.
• Two sub-sets of logistic regression model were made– Adult-tense model predicts tense vs. non-tense (i.e., lax and
asp.)– Adult- lax model predicts lax vs. asp.
Results: Analysis (2) adults’ stops
Mixed effects logistic regression model:target category (target or non-target) as a function of
VOT, H1-H2 and F0
€
logtarget consonant
1− target consonant
⎛
⎝ ⎜
⎞
⎠ ⎟= β 0 + β1VOT + β 2F0 + β 3H1H2
Results: Analysis (2) adults’ stops
Steeper slope of VOT than H1-H2
1. Adult-tense model: tense (vs. non-tense) ~ VOT + F0 + H1-H2
Results: Analysis (2) adults’ stops
2. Adult-lax model: : lax (vs. asp) ~ VOT + F0 + H1-H2
Steeper slope of F0 than VOT
Children’s stops
2 year olds
4 year olds
F0 H1-H2VOT
short lag
short lag
•VOT: overlap at a short lag VOT range at a younger age•F0: relatively lower F0 for lax stops•H1-H2: lower H1-H2 for tense stops at an older age.
Results – Analysis 3: Acoustic characteristics
• β1, β2, and β3 (coefficients)
: the absolute value of coefficient is the relative contribution of each predictor in determining the dependent variable.
• Two sub-sets of logistic regression model were made– Child-tense model predicts transcribed tense vs. non-
tense (i.e., lax and asp.)– Child-lax model predicts transcribed lax vs. asp.
Results: Analysis (3) children’ stops
Mixed effects logistic regression model:transcribed category (transc. target or not) as a function of
VOT, H1-H2 and F0
€
logtranscribed consonant
1− transcribed consonant
⎛
⎝ ⎜
⎞
⎠ ⎟= β 0 + β1VOT + β 2F0 + β 3H1H2
Results: Analysis (3) children’s stops
Child-tense model: tense (vs. non-tense) ~ VOT + H1-H2 + F0
steepest slope of VOT
H1-H2
VOT F0
not sig.
Child-lax model: lax (vs. asp.) ~ VOT + H1-H2 + F0
Almost equally steep slope of VOT and F0
H1-H2
VOT F0
Results: Analysis (3) children’s stops
Summary and Conclusion
• Transcription accuracy: early mastery of tense stops
• Acoustic characteristics: Adults’ stops
– VOT: short lag VOT (tense), long lag VOT (lax and asp.)– F0: lower F0 (lax), higher (tense and asp.)– H1-H2: negative H1-H2 (tense), positive H1-H2 (lax and asp.) Children’s stops:
– overlap at the three acoustic dimensions. – VOT: three categories at a short lag VOT range in a younger
age.
• Quantitative model relating transcription categories to acoustic parameters showed that:The transcriber identified the children’s productions as tense primarily based on the VOT values of the productions.The transcribed was less influenced by F0 and H1-H2.
• This dominant role of VOT in the transcription judgment of tense stops can explain the early mastery of tense stops– children produce a short lag VOT value before
mastering a long lag VOT or a lead VOT cross-linguistically.
– having a short lag VOT suffices for a transcriber to identify it as a correct production of a tense stop in Korean.
• Given the role of VOT in the transcription analysis, the early mastery of the Korean tense stop is not such an exceptional pattern after all.
Summary and Conclusion
Acknowledgement
• This study was supported by NIDCD Grant 02932.
• Thanks to
The children who participated in the study and the parents who gave their consent.
Thank you!!!
Ευχαριστώ πολύ
감사합니다24
25/taŋ.gɨn/ carrot
26/tal.phɛŋ.i/ snail
Summary of findings• Transcription accuracy: early mastery of tense stops
• Acoustic characteristics Adults’ stops:
– VOT: short lag VOT (tense), long lag VOT (lax and asp.)– F0: lower F0 (lax), higher (tense and asp.)– H1-H2: negative H1-H2 (tense), positive H1-H2 (lax and asp.) Children’s stops:
– overlap at the three acoustic dimensions. – VOT: three categories at a short lag VOT range in a younger
age.
• Mixed effects logistic regression models– transcribed tense vs. non-tense was primarily predicted by
VOT and less by H1-H2. – transcribed lax vs. aspirated stops were explained by the F0
and VOT.
Korean tense stop: • short lag VOT • relatively high F0, creaky voice quality
Transcriptions and acoustic parameters:The quantitative model of the role of VOT showed
that:• The transcriber identified the children’s productions
of the tense target dominantly by the VOT values of the tokens, less affected by other acoustic aspects such as F0 or H1-H2.
Discussion and Conclusion