Download English vowel discrimination

Based on Lai Yi-shiu (2009).
Cognitive linguistics.
Abstract
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• Motivation: Much research has been dedicated to the
tense-lax vowel contrast production, but few studies
focus on L2 learners’ discriminatory and assimilatory
patterns of complete English vowels inventories.
• Experiment1: investigated Chinese-speaking learners’
English vowel discrimination.
Experiment2: how these learners classified English
vowels and assimilated them to Mandarin categories.
• Finding: Assimilatory patterns between L1-L2 segments
in Perceptual Assimilation Model may not fully account
for the perception saliency hierarchy and suggested
one Tri-dimensional Model for interpreting L2 vowel
perception.
Introduction
• In the field of second language acquisition,
English vowels pronunciation plays an essential
role.
• Especially, contrasts of tense and lax vowels,
which are present in English but not in Mandarin
Chinese, have been extensively studies in the
interlanguage phonology for Chinese-speaking
EFL learners.
• In these studies, Chinese speakers often
confuse and mispronounce English tense/lax
vowel pairs, and such a failure may result in
misunderstandings when they converse with
native English speakers.
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Introduction
• Speech Learning Model(SLM): L1-L2 segment
inventories and adopts the terminology of
“similar/old sounds” and “new sounds” in
interpreting speech learning. E.g.
• Similarity Effect: Most L2 learners fail to
articulate or discriminate some non-native
contrasts because they interpret them as being
equivalent. E.g.
• Perceptual Assimilation Model(PAM): L2 learners
perceptually assimilate non-native contrasts to
L1 phonetic categories, and that non-native
perception is often filtered by linguistic
experience.
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Introduction
• Purpose1: Chinese-speaking EFL learners in
Taiwan differentially discriminate which English
vowels
Experiment1: How Taiwanese EFL learners
discriminated English vowel pairs and which
pairs posed the greatest challenges for them
were addressed.
• Perpose2: Chinese-speaking learners classify
which English vowels as similar or new tokens.
Experiment2: Taiwanese EFL learners were
asked to classify English vowels as similar or
new tokens and transcribe these vowels with
Mandarin Chinese phonetic symbols or with IPA
notations.
Literature Review
Phonological Comparison among
English and Mandarin Vowels
• English vowel system is composed of 11 vowels
Tongue articulation: high-front
low-front
Tenseness: tense
lax
‧Chinese vowel system
7 simple vowels
4 diphthongs
high-back
low-back
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Literature Review
Phonological Comparison among
English and Mandarin Vowels
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• Vowels shared in English and Chinese
familiar or similar sounds for Mandarin speakers
• Vowels not shared in English and Chinese
unfamiliar or new sounds
• Tenseness dose not play a significant role in
distinguishing Chinese phonemes, native speakers
may encounter difficulty in producing and
perceiving lax vowels, which contain marked
features.
Literature Review
Second/Foreign Language Phonology
of Vowel Perception
• Universal factors: The template of Mandarin
tense-only vowels has been internalized and
further become filters when native speakers
of Mandarin begin to acquire English as a
foreign language.
• Perceptions of English vowels( front vowels):
Mandarin speakers would be assumed to
perform better in their identification of
English vowels
, than
.
However, Mandarin speakers have better
perception
than
.
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Literature Review
Second/Foreign Language Phonology
of Vowel Perception
• New vowels: Mandarin speakers mainly
contrasted new pairs of vowels by length,
while English speakers distinguished these
pairs by more parameters (duration and the
first two formats).
• High vowels: Mandarin speakers showed
excellent perception of English high vowels in
listening task.
• Tense-lax vowels contrast??
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Literature Review
Second/Foreign Language Phonology
of Vowel Perception
• SLM: The labels “new” and “similar” can be
assigned only after evaluating learners’
judgments of similarity.
• Similarity Effect: On the contrary, the
greater dissimilarity between L1 and L2
sounds is perceived, the easier L2 learners
might acquire L2 sounds.
• PAM:L2 learners may perceptually assimilate
non-native contrasts to their L1 phonemic
categories.
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Literature Review
Second/Foreign Language Phonology
of Vowel Perception
• PAM:
non-native language
native language
Method
Research Questions
• How did Taiwanese EFL learners discriminate
English vowels? To what extent did learners
of high English proficiency differ from those
of low English proficiency?
• How did Taiwanese EFL learners assimilate
English vowels to their L1 Mandarin phonetic
categories? To what extent did learners of
high English proficiency differ from of low
English proficiency.
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Method
Participants
• 90 speakers of Mandarin Chinese in Taiwan
who learn English as a foreign language.
• College students, ages ranged from 19 to 22
• They had been learning English for at least 6
years.
• Non of them lived in an English- speaking
country.
• Pre-test is one simulated TOEIC test, and
divided the participants on the basis of the
test scores.
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Method
Participants
Group 1
45 participants
Group2
45 participants
10males 35femles
20males 25females
mean score of 530
mean score of 352
English majors
non-English-majors
HEFL
LEFL
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Method
Experiment1: English vowel discrimination
• Goal: Examine Taiwanese EFL learners’ English
vowel discrimination.
• Procedure: Participants listened to the prerecorded sounds to decided whether two
segments in each word were the same or
different.
If the same, listeners had to circle SAME and
circle the word matched the segment they
heard.
If different, listeners had to identify which
words were the first and second sounds they
heard.
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Method
Experiment1: English vowel discrimination
• Materials: 7 English minimal pairs in 3 trial-types,
repeated twice by 2 English teachers, and added 8
distracters.
• Skeleton: [h_ t]
• 7English minimal pairs:
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• 3 trial-types: A-A,A-B, and B-A
• 2 teachers’ voices
• 8 distracters: e.g. hit-hid, heed-heat, hate-hayed
7×3×2＋8=50
Method
Experiment2: English vowel assimilation
• Materials: the same as experiment 1
• Participants’ tasks:
(1) To label each of 11 English vowels as
“Similar” or “New” vowels
(2) If the vowels are categorized as
“Similar” sounds, participants had to
transcribe these vowels with Zhuyin
Fuhao or with IPA transcriptions.
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Method
Data Analysis
• Pair 1:
SAME
0score
Distinguished 1 score
• 3 trails: A-A
A-B
the highest score is 3
B-A
• Focus:
(a) perceptual discrimination of English vowels
(b) perceptual assimilation of English vowels to
Mandarin Chinese vowel categories
Result and Discussion
English Vowel Discrimination
• The language experience
between two different
groups acted as a
significant factor in
distinguish English vowel
contrasts.
• Both groups tended to
misperceive English
vowel pairs to some
extent.
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Result and Discussion
English Vowel Discrimination
The hierarchy reflected some similar
patterns shared by Taiwanese EFL
learners of different proficiency levels.
Finding in
pair was in
disagreement with Luo(2002), in which
speakers of Mandarin Chinese had
excellent perception of English high
vowels. The reason might be in Luo’s
study, only high vowels were examined
and excluded mid and low vowels.
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Result and Discussion
English Vowel Discrimination
Misperceiving directions
Misperceived pairs as tense
vowels:
Pair 1, 4, 5
Different groups respond
differently to one tense-lax
vowel pair:
Pair 2
No dominant misperceiving
directions:
Pair 3, 6, 7
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Result and Discussion
English Vowel Assimilation
tokens similar
vowels
groups
HEFL
LEFL
new
vowels
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Result and Discussion
English Vowel Assimilation
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Result and Discussion
English Vowel Assimilation
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Result and Discussion
Discussion
• HEFL group performed significantly better than
the LEFL group in discriminating most English
vowel pairs.
• Most English tense-lax vowel contrasts displayed
a greater tendency to be perceived as tense.
• Different English proficiency levels displayed
different perceptual assimilation patterns in
Experiment 2.
(HEFL--- little overlap between English tense
vowels and their lax counterparts.
LEFL---high degree of overlap in classification
between English tense and lax vowels)
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Result and Discussion
Discussion
• Support to the Speech Learning Model, most
English lax vowels were all rated as “new” phones,
and tense vowels were “similar” phones for HEFL
learners.
• LEFL learners consider
as the similar,
and less discriminating this pair, which supports
Similarity Effect, the more and L2 segment was
perceptually to similar to that of an L1 segment.
• Agree with the importance of L2 learning
experience. (LEFL learners tend to assimilate
English tense-lax vowels as L1 tense vowels, HEFL
learners become aware of discrimination of
English vowel pairs.)
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Result and Discussion
Discussion
Perceptual Assimilation Model
Three perceptual assimilation patterns of non-native
segments
(a) being assimilated to a native category
(b) being assimilated as uncategorizable speech
sound
(c) not being assimilated to speech
x
Discrimination is expected to be excellent when two
non-native categories are assimilated to two
different native categories,( UC or CU) and poor
discrimination occurs when two non-native
categories are assimilated to a single native
category. (CC or UU)
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?
Result and Discussion
Discussion
PAM is helpful in two ways
(1) It is advantageous in accounting for the UC or
CU types were better discriminated than the CC
types in LEFL group.
e.g.
(2) Provide plausible account why the English
pairs
poses fewer challenges for HEFL
than for LEFL. (HEFL--- CU, LEFL--- CC)
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Result and Discussion
Discussion
PAM fail to address two questions
(1) Why did the HEFL group perform the best
in the UU pair than the CU or UC pairs ?
(UU) ＞
(CU or UC)
(2) Under which effect did these learners
experience different degree of difficulties
in L2 vowel discrimination?
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Result and Discussion
Discussion
•
To account for these unexpected findings , the
researcher drew on the facts from markedness
effects in the world languages.
(1) Sonority scale:
Ranking in perception saliency in English vowel
discrimination might be a major result of the
sonority scale.
Low vowels are claimed to be most sonorous , while
high vowels least sonorous, [i] context might be
comparatively less salient to ear and be more
challenging for listeners.
＞
＞
The finding confirmed the universal sonority scale
＞
＞
Result and Discussion
Discussion
(2) Minimal Sonority Distance (MSD) Model
e.g. high vowels are 1, mid vowels are 2, low
vowels are 3
Sonority distance in
is 3-1=2
Sonority distance in
is 2-2=0
Vowel pairs with higher MSD settings were
easier to discriminate than those with lower
MSD settings.
＞
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Result and Discussion
Discussion
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Tri-dimensional model for L2 vowel perception
Conclusion
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• Learners of different English proficiency
levels demonstrated similar patterns, but with
different degrees of sensitiveness in
perceiving English vowel pairs and slightly
different misperceiving directions were also
identified.
• PAM alone might not fully account for the
current finding. One tri-dimensional model
for L2 vowel perception, in which language
factors and markedness effects were
actively involved, was thus suggested.
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Conclusion
• Tense/ lax distinctions in English should thus
be made explicit to EFL learners by
phonological structures and tri-dimensional
model in achieving competence at segmental
levels.
• L2/FL phonemic categories can be enhanced
with auditory training and appropriate
methods, like minimal pairs, in which learners
attention could be drawn systematically to
the confusing segments in perception.
• The further testing with tri-dimensional
model must be carried out to substantiate its
feasibility and accountability in the future L2
perceptual studies.
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