While recent research suggests that visual biofeedback can facilitate speech production training in clinical populations and second language (L2) learners, individual learners' responsiveness to biofeedback is highly variable. This study investigated the hypothesis that the type of biofeedback provided, visual-acoustic versus ultrasound, could interact with individuals' acuity in auditory and somatosensory domains. Specifically, it was hypothesized that learners with lower acuity in a sensory domain would show greater learning in response to biofeedback targeting that domain. Production variability and phonological awareness were also investigated as predictors. Sixty female native speakers of English received 30 min of training, randomly assigned to feature visual-acoustic or ultrasound biofeedback, for each of two Mandarin vowels. On average, participants showed a moderate magnitude of improvement (decrease in Euclidean distance from a native-speaker target) across both vowels and biofeedback conditions. The hypothesis of an interaction between sensory acuity and biofeedback type was not supported, but phonological awareness and production variability were predictive of learning gains, consistent with previous research. Specifically, high phonological awareness and low production variability post-training were associated with better outcomes, although these effects were mediated by vowel target. This line of research could have implications for personalized learning in both L2 pedagogy and clinical practice.

1.
Adler-Bock
,
M.
,
Bernhardt
,
B. M.
,
Gick
,
B.
, and
Bacsfalvi
,
P.
(
2007
). “
The use of ultrasound in remediation of North American English /r/ in 2 adolescents
,”
Am. J. Speech-Lang. Pathol.
16
(
2
),
128
139
.
2.
Akahane-Yamada
,
R.
,
McDermott
,
E.
,
Adachi
,
T.
,
Kawahara
,
H.
, and
Pruitt
,
J. S.
(
1998
). “
Computer-based second language production training by using spectrographic representation and HMM-based speech recognition scores
,” paper presented at the
Fifth International Conference on Spoken Language Processing
.
3.
Bacsfalvi
,
P.
, and
Bernhardt
,
B. M.
(
2011
). “
Long-term outcomes of speech therapy for seven adolescents with visual feedback technologies: Ultrasound and electropalatography
,”
Clin. Linguist. Phonet.
25
(
11-12
),
1034
1043
.
4.
Bernhardt
,
B.
,
Gick
,
B.
,
Bacsfalvi
,
P.
, and
Adler-Bock
,
M.
(
2005
). “
Ultrasound in speech therapy with adolescents and adults
,”
Clin. Linguist. Phonet.
19
(
6-7
),
605
617
.
5.
Best
,
C. T.
(
1995
). “
A direct realist view of cross-language speech perception
,” in
Speech Perception and Linguistic Experience: Issues in Cross-Language Research
, edited by
W.
Strange
(
York Press
,
Baltimore, MD
), pp.
171
204
.
6.
Best
,
C. T.
,
Halle
,
P.
,
Bohn
,
O.-S.
, and
Faber
,
A.
(
2003
). “
Cross-language perception of nonnative vowels: Phonological and phonetic effects of listeners' native languages
,” paper presented at the
Proceedings of the 15th International Congress of Phonetic Sciences
.
7.
Bliss
,
H.
,
Abel
,
J.
, and
Gick
,
B.
(
2018
). “
Computer-assisted visual articulation feedback in L2 pronunciation instruction
,”
J. Second Lang. Pronunciation
4
(
1
),
129
153
.
8.
Boersma
,
P.
, and
Weenink
,
D.
(
2016
). “
Praat: Doing phonetics by computer (version 6.0.18) [computer program]
,” http://www.praat.org (Last viewed 5 April 2019).
9.
Borrie
,
S. A.
, and
Schäfer
,
M. C.
(
2015
). “
The role of somatosensory information in speech perception: Imitation improves recognition of disordered speech
,”
J. Speech Lang. Hear. Res.
58
(
6
),
1708
1716
.
10.
Bradlow
,
A. R.
,
Pisoni
,
D. B.
,
Akahane-Yamada
,
R.
, and
Tohkura
,
Y. I.
(
1997
). “
Training Japanese listeners to identify English /r/ and /l/: IV. Some effects of perceptual learning on speech production
,”
J. Acoust. Soc. Am.
101
(
4
),
2299
2310
.
11.
Carey
,
M.
(
2004
). “
CALL visual feedback for pronunciation of vowels: Kay Sona-Match
,”
CALICO J.
21
,
571
601
.
12.
Catford
,
J. C.
, and
Pisoni
,
D.
(
1970
). “
Auditory versus articulatory training in exotic sounds
,”
Mod. Lang. J.
54
,
477
481
.
13.
Chang
,
C. B.
,
Yao
,
Y.
,
Haynes
,
E. F.
, and
Rhodes
,
R.
(
2011
). “
Production of phonetic and phonological contrast by heritage speakers of Mandarin
,”
J. Acoust. Soc. Am.
129
(
6
),
3964
3980
.
14.
Chen
,
Y.
,
Robb
,
M.
,
Gilbert
,
H.
, and
Lerman
,
J.
(
2001
). “
Vowel production by Mandarin speakers of English
,”
Clin. Linguist. Phonet.
15
(
6
),
427
440
.
15.
Christiner
,
M.
, and
Reiterer
,
S. M.
(
2015
). “
A Mozart is not a Pavarotti: Singers outperform instrumentalists on foreign accent imitation
,”
Front. Hum. Neurosci.
9
,
482
.
16.
Dörnyei
,
Z.
(
1998
). “
Motivation in second and foreign language learning
,”
Lang. Teach.
31
(
3
),
117
135
.
17.
Dowd
,
A.
,
Smith
,
J.
, and
Wolfe
,
J.
(
1998
). “
Learning to pronounce vowel sounds in a foreign language using acoustic measurements of the vocal tract as feedback in real time
,”
Lang. Speech
41
(
1
),
1
20
.
18.
Engwall
,
O.
(
2006
). “
Feedback strategies of human and virtual tutors in pronunciation training
,”
Speech Music and Hearing—Quarterly Progress and Status Report
Vol.
48
(
1
),
11
34
.
19.
Fitch
,
W. T.
(
1997
). “
Vocal tract length and formant frequency dispersion correlate with body size in rhesus macaques
,”
J. Acoust. Soc. Am.
102
(
2
),
1213
1222
.
20.
Fitch
,
W. T.
, and
Giedd
,
J.
(
1999
). “
Morphology and development of the human vocal tract: A study using magnetic resonance imaging
,”
J. Acoust. Soc. Am.
106
(
3
),
1511
1522
.
21.
Flege
,
J. E.
(
1987
). “
The production of ‘new’ and ‘similar’ phones in a foreign language: Evidence for the effect of equivalence classification
,”
J. Phonetics
15
(
1
),
47
65
.
22.
Flege
,
J. E.
(
1995
). “
Second language speech learning: Theory, findings, and problems
,” in
Speech Perception and Linguistic Experience
, edited by
W.
Strange
(
York Press
,
Timonium, MD
), pp.
233
277
.
23.
Franken
,
M. K.
,
Acheson
,
D. J.
,
McQueen
,
J. M.
,
Eisner
,
F.
, and
Hagoort
,
P.
(
2017
). “
Individual variability as a window on production-perception interactions in speech motor control
,”
J. Acoust. Soc. Am.
142
(
4
),
2007
2018
.
24.
Fucci
,
D.
(
1972
). “
Oral vibrotactile sensation: An evaluation of normal and defective speakers
,”
J. Speech Lang. Hear. Res.
15
(
1
),
179
184
.
25.
Fucci
,
D. J.
, and
Robertson
,
J. H.
(
1971
). “ 
‘Functional’ defective articulation: An oral sensory disturbance
,”
Percept. Mot. Skills
33
(
3
),
711
714
.
26.
Ghosh
,
S. S.
,
Matthies
,
M. L.
,
Maas
,
E.
,
Hanson
,
A.
,
Tiede
,
M.
,
Menard
,
L.
,
Guenther
,
F. H.
,
Lane
,
H.
, and
Perkell
,
J. S.
(
2010
). “
An investigation of the relation between sibilant production and somatosensory and auditory acuity
,”
J. Acoust. Soc. Am.
128
(
5
),
3079
3087
.
27.
Gick
,
B.
,
Bernhardt
,
B.
,
Bacsfalvi
,
P.
,
Wilson
,
I.
, and
Zampini
,
M.
(
2008
). “
Ultrasound imaging applications in second language acquisition
,”
Phonol. Second Lang. Acquis.
36
,
315
328
.
28.
Gilbert
,
J. B.
(
2010
). “
Pronunciation as orphan: What can be done?
,”
Speak Out!
43
,
3
7
.
29.
Guenther
,
F. H.
(
1994
). “
A neural network model of speech acquisition and motor equivalent speech production
,”
Biol. Cybernet.
72
(
1
),
43
53
.
30.
Guenther
,
F. H.
(
1995
). “
Speech sound acquisition, coarticulation, and rate effects in a neural network model of speech production
,”
Psychol. Rev.
102
(
3
),
594
.
31.
Guenther
,
F. H.
(
2016
).
Neural Control of Speech
(
MIT Press
,
Cambridge, MA
).
32.
Guenther
,
F. H.
,
Ghosh
,
S. S.
, and
Tourville
,
J. A.
(
2006
). “
Neural modeling and imaging of the cortical interactions underlying syllable production
,”
Brain Lang.
96
(
3
),
280
301
.
33.
Guenther
,
F. H.
,
Hampson
,
M.
, and
Johnson
,
D.
(
1998
). “
A theoretical investigation of reference frames for the planning of speech movements
,”
Psychol. Rev.
105
(
4
),
611
.
34.
Halwani
,
G. F.
,
Loui
,
P.
,
Rueber
,
T.
, and
Schlaug
,
G.
(
2011
). “
Effects of practice and experience on the arcuate fasciculus: Comparing singers, instrumentalists, and non-musicians
,”
Front. Psychol.
2
,
156
.
35.
Hanulíková
,
A.
,
Dediu
,
D.
,
Fang
,
Z.
,
Bašnaková
,
J.
, and
Huettig
,
F.
(
2012
). “
Individual differences in the acquisition of a complex L2 phonology: A training study
,”
Lang. Learn.
62
,
79
109
.
36.
Hardcastle
,
W. J.
,
Gibbon
,
F. E.
, and
Jones
,
W.
(
1991
). “
Visual display of tongue-palate contact: Electropalatography in the assessment and remediation of speech disorders
,”
Br. J. Disord. Commun.
26
(
1
),
41
74
.
37.
Hattori
,
K.
, and
Iverson
,
P.
(
2010
). “
Examination of the relationship between L2 perception and production: An investigation of English /r/-/l/ perception and production by adult Japanese speakers
,” paper presented at the
Second Language Studies: Acquisition, Learning, Education and Technology
.
38.
Hickok
,
G.
(
2012
). “
Computational neuroanatomy of speech production
,”
Nat. Rev. Neurosci.
13
(
2
),
135
.
39.
Hitchcock
,
E. R.
,
McAllister Byun
,
T.
,
Swartz
,
M.
, and
Lazarus
,
R.
(
2017
). “
Efficacy of electropalatography for treating misarticulation of /r/
,”
Am. J. Speech-Lang. Pathol.
26
(
4
),
1141
1158
.
40.
Hu
,
C. F.
(
2003
). “
Phonological memory, phonological awareness, and foreign language word learning
,”
Lang. Learn.
53
(
3
),
429
462
.
41.
Hu
,
C. F.
(
2010
). “
Phonological bases for L2 morphological learning
,”
J. Psycholinguist. Res.
39
(
4
),
305
322
.
42.
Hu
,
X.
,
Ackermann
,
H.
,
Martin
,
J. A.
,
Erb
,
M.
,
Winkler
,
S.
, and
Reiterer
,
S. M.
(
2013
). “
Language aptitude for pronunciation in advanced second language (L2) learners: Behavioural predictors and neural substrates
,”
Brain Lang.
127
(
3
),
366
376
.
43.
Hummel
,
K. M.
(
2009
). “
Aptitude, phonological memory, and second language proficiency in nonnovice adult learner
,”
Appl. Psycholinguist.
30
(
2
),
225
249
.
44.
Jacobs
,
R.
,
Serhal
,
C. B.
, and
van Steenberghe
,
D.
(
1998
). “
Oral stereognosis: A review of the literature
,”
Clin. Oral Investig.
2
(
1
),
3
10
.
45.
Kartushina
,
N.
, and
Frauenfelder
,
U. H.
(
2014
). “
On the effects of L2 perception and of individual differences in L1 production on L2 pronunciation
,”
Front. Psychol.
5
,
1246
.
46.
Kartushina
,
N.
,
Hervais-Adelman
,
A.
,
Frauenfelder
,
U. H.
, and
Golestani
,
N.
(
2015
). “
The effect of phonetic production training with visual feedback on the perception and production of foreign speech sounds
,”
J. Acoust. Soc. Am.
138
(
2
),
817
832
.
47.
Kartushina
,
N.
,
Hervais-Adelman
,
A.
,
Frauenfelder
,
U. H.
, and
Golestani
,
N.
(
2016
). “
Mutual influences between native and non-native vowels in production: Evidence from short-term visual articulatory feedback training
,”
J. Phonetics
57
,
21
39
.
48.
Kawahara
,
H.
,
Morise
,
M.
,
Banno
,
H.
, and
Skuk
,
V. G.
(
2013
). “
Temporally variable multi-aspect N-way morphing based on interference-free speech representations
,” paper presented at the
Signal and Information Processing Association Annual Summit and Conference (APSIPA)
, Asia-Pacific.
49.
Kendall
,
T.
,
Thomas
,
E. R.
, and
Kendall
,
M. T.
(
2018
). “
vowels: Vowel manipulation, normalization, and plotting [R package]
,” available at https://cran.r-project.org/web/packages/vowels/ (Last viewed 5 April 2019).
50.
Kleber
,
B. A.
, and
Zarate
,
J. M.
(
2014
). “
The neuroscience of singing
,” in
The Oxford Handbook of Singing
(
Oxford University Press
,
Oxford, UK
).
51.
Kocjančičo Antolík
,
T. K.
,
Pillot-Loiseau
,
C.
, and
Kamiyama
,
T.
(
2019
). “
The effectiveness of real-time ultrasound visual feedback on tongue movements in L2 pronunciation training
,”
J. Second Lang. Pronunciation
5
(
1
),
72
97
.
52.
Lakens
,
D.
(
2017
). “
Equivalence tests: A practical primer for t tests, correlations, and meta-analyses
,”
Soc. Psychol. Personal. Sci.
8
(
4
),
355
362
.
53.
Lametti
,
D. R.
,
Nasir
,
S. M.
, and
Ostry
,
D. J.
(
2012
). “
Sensory preference in speech production revealed by simultaneous alteration of auditory and somatosensory feedback
,”
J. Neurosci.
32
(
27
),
9351
9358
.
54.
Lennes
,
M.
(
2003
). “
Collect_formant_data_from_files, Praat [Praat script]
,” available at https://github.com/FieldDB/Praat-Scripts/blob/master/collect_formant_data_from_files.praat (Last viewed 5 April 2019).
55.
Levy
,
E. S.
, and
Strange
,
W.
(
2008
). “
Perception of French vowels by American English adults with and without French language experience
,”
J. Phonetics
36
(
1
),
141
157
.
56.
McAllister Byun
,
T.
(
2017
). “
Efficacy of visual–acoustic biofeedback intervention for residual rhotic errors: A single-subject randomization study
,”
J. Speech Lang. Hear. Res.
60
(
5
),
1175
1193
.
57.
McAllister Byun
,
T.
, and
Campbell
,
H.
(
2016
). “
Differential effects of visual-acoustic biofeedback intervention for residual speech errors
,”
Front. Hum. Neurosci.
10
,
567
.
58.
McAllister Byun
,
T.
, and
Hitchcock
,
E. R.
(
2012
). “
Investigating the use of traditional and spectral biofeedback approaches to intervention for /r/ misarticulation
,”
Am. J. Speech-Lang. Pathol.
21
(
3
),
207
221
.
59.
McAllister Byun
,
T.
,
Hitchcock
,
E. R.
, and
Swartz
,
M. T.
(
2014
). “
Retroflex versus bunched in treatment for rhotic misarticulation: Evidence from ultrasound biofeedback intervention
,”
J. Speech Lang. Hear. Res.
57
(
6
),
2116
2130
.
60.
McBride-Chang
,
C.
(
1996
). “
Models of speech perception and phonological processing in reading
,”
Child Dev.
67
(
4
),
1836
1856
.
61.
McNutt
,
J. C.
(
1977
). “
Oral sensory and motor behaviors of children with /s/ or /r/ misarticulations
,”
J. Speech Lang. Hear. Res.
20
(
4
),
694
703
.
62.
Milovanov
,
R.
,
Pietilä
,
P.
,
Tervaniemi
,
M.
, and
Esquef
,
P. A.
(
2010
). “
Foreign language pronunciation skills and musical aptitude: A study of Finnish adults with higher education
,”
Learn. Individ. Differ.
20
(
1
),
56
60
.
63.
Mora
,
J. C.
,
Rochdi
,
Y.
, and
Kivistö-de Souza
,
H.
(
2014
). “
Mimicking accented speech as L2 phonological awareness
,”
Lang. Aware.
23
(
1-2
),
57
75
.
64.
Nagle
,
C. L.
(
2018
). “
Examining the temporal structure of the perception–production link in second language acquisition: A longitudinal study
,”
Lang. Learn.
68
(
1
),
234
270
.
65.
Nasir
,
S. M.
, and
Ostry
,
D. J.
(
2008
). “
Speech motor learning in profoundly deaf adults
,”
Nat. Neurosci.
11
(
10
),
1217
1222
.
66.
Newman
,
R. S.
(
2003
). “
Using links between speech perception and speech production to evaluate different acoustic metrics: A preliminary report
,”
J. Acoust. Soc. Am.
113
(
5
),
2850
2860
.
67.
Niziolek
,
C. A.
,
Nagarajan
,
S. S.
, and
Houde
,
J. F.
(
2013
). “
What does motor efference copy represent? Evidence from speech production
,”
J. Neurosci.
33
(
41
),
16110
16116
.
68.
Nushi Kochaksaraie
,
M.
, and
Makiabadi
,
H.
(
2018
). “
Second language learners' phonological awareness and perception of foreign accentedness and comprehensibility by native and non-native English speaking EFL teachers
,”
J. Teach. Lang. Skills
36
(
4
),
103
140
.
69.
Okuno
,
T.
, and
Hardison
,
D. M.
(
2016
). “
Perception-production link in L2 Japanese vowel duration: Training with technology
,”
Lang. Learn. Technol.
20
(
2
),
61
80
.
70.
Olson
,
D. J.
(
2014
). “
Benefits of visual feedback on segmental production in the L2 classroom
,”
Lang. Learn. Technol.
18
(
3
),
173
192
.
71.
Peperkamp
,
S.
, and
Bouchon
,
C.
(
2011
). “
The relation between perception and production in L2 phonological processing
,” paper presented at the
Twelfth Annual Conference of the International Speech Communication Association
.
72.
Perkell
,
J. S.
,
Guenther
,
F. H.
,
Lane
,
H.
,
Matthies
,
M. L.
,
Stockmann
,
E.
,
Tiede
,
M.
, and
Zandipour
,
M.
(
2004a
). “
The distinctness of speakers' productions of vowel contrasts is related to their discrimination of the contrasts
,”
J. Acoust. Soc. Am.
116
(
4
),
2338
2344
.
73.
Perkell
,
J. S.
,
Matthies
,
M. L.
,
Tiede
,
M.
,
Lane
,
H.
,
Zandipour
,
M.
,
Marrone
,
N.
,
Stockmann
,
E.
, and
Guenther
,
F. H.
(
2004b
). “
The distinctness of speakers' /s/-/∫/ contrast is related to their auditory discrimination and use of an articulatory saturation effect
,”
J. Speech Lang. Hear. Res.
47
(
6
),
1259
1269
.
74.
Perrachione
,
T. K.
,
Lee
,
J.
,
Ha
,
L. Y.
, and
Wong
,
P. C.
(
2011
). “
Learning a novel phonological contrast depends on interactions between individual differences and training paradigm design
,”
J. Acoust. Soc. Am.
130
(
1
),
461
472
.
75.
Posedel
,
J.
,
Emery
,
L.
,
Souza
,
B.
, and
Fountain
,
C.
(
2012
). “
Pitch perception, working memory, and second-language phonological production
,”
Psychol. Music
40
(
4
),
508
517
.
76.
Preston
,
J. L.
, and
Leaman
,
M.
(
2014
). “
Ultrasound visual feedback for acquired apraxia of speech: A case report
,”
Aphasiology
28
(
3
),
278
295
.
77.
Preston
,
J. L.
,
Leece
,
M. C.
, and
Maas
,
E.
(
2016
). “
Intensive treatment with ultrasound visual feedback for speech sound errors in childhood apraxia
,”
Front. Hum. Neurosci.
10
,
440
.
78.
Preston
,
J. L.
,
McAllister
,
T.
,
Phillips
,
E.
,
Boyce
,
S.
,
Tiede
,
M.
,
Kim
,
J. S.
, and
Whalen
,
D. H.
(
2018
). “
Treatment for residual rhotic errors with high-and low-frequency ultrasound visual feedback: A single-case experimental design
,”
J. Speech Lang. Hear. Res.
61
(
8
),
1875
1892
.
79.
Preston
,
J. L.
,
McAllister
,
T.
,
Phillips
,
E.
,
Boyce
,
S. E.
,
Tiede
,
M.
,
Kim
,
J. S.
, and
Whalen
,
D. H.
(
2019
). “
Remediating residual rhotic errors with traditional and ultrasound-enhanced treatment: A single-case experimental study
,”
Am. J. Speech-Lang. Pathol.
28
,
1167
1183
.
80.
Preston
,
J. L.
,
McCabe
,
P.
,
Rivera-Campos
,
A.
,
Whittle
,
J. L.
,
Landry
,
E.
, and
Maas
,
E.
(
2014
). “
Ultrasound visual feedback treatment and practice variability for residual speech sound errors
,”
J. Speech Lang. Hear. Res.
57
(
6
),
2102
2115
.
81.
R Core Team
. (
2015
). “
R: A language and environment for statistical computing [software]
,” (R foundation for Statistical Computing, Vienna, Austria), available at http://www.R-project.org/ (Last viewed 5 April 2019).
82.
Reiterer
,
S. M.
,
Hu
,
X.
,
Erb
,
M.
,
Rota
,
G.
,
Nardo
,
D.
,
Grodd
,
W.
, and
Ackermann
,
H.
(
2011
). “
Individual differences in audio-vocal speech imitation aptitude in late bilinguals: Functional neuro-imaging and brain morphology
,”
Front. Psychol.
2
,
271
.
83.
Rota
,
G.
, and
Reiterer
,
S.
(
2009
). “
Cognitive aspects of pronunciation talent
,”
Lang. Talent Brain Act.
1
,
67
96
.
84.
Schmidt
,
R.
(
1990
). “
The role of consciousness in second language learning
,”
Appl. Linguist.
11
(
2
),
129
158
.
85.
Schmidt
,
R.
(
1993
). “
Awareness and second language acquisition
,”
Annu. Rev. Appl. Linguist.
13
,
206
226
.
86.
Schwartz
,
J.-L.
,
Basirat
,
A.
,
Ménard
,
L.
, and
Sato
,
M.
(
2012
). “
The Perception-for-Action-Control Theory (PACT): A perceptuo-motor theory of speech perception
,”
J. Neurolinguist.
25
(
5
),
336
354
.
87.
Simmonds
,
A. J.
,
Wise
,
R. J.
,
Dhanjal
,
N. S.
, and
Leech
,
R.
(
2011
). “
A comparison of sensory-motor activity during speech in first and second languages
,”
J. Neurophysiol.
106
(
1
),
470
478
.
88.
Slevc
,
L. R.
, and
Miyake
,
A.
(
2006
). “
Individual differences in second-language proficiency: Does musical ability matter?
,”
Psychol. Sci.
17
(
8
),
675
681
.
89.
Steele
,
C. M.
,
Hill
,
L.
,
Stokely
,
S.
, and
Peladeau-Pigeon
,
M.
(
2014
). “
Age and strength influences on lingual tactile acuity
,”
J. Texture Stud.
45
(
4
),
317
323
.
90.
Villacorta
,
V. M.
,
Perkell
,
J. S.
, and
Guenther
,
F. H.
(
2007
). “
Sensorimotor adaptation to feedback perturbations of vowel acoustics and its relation to perception
,”
J. Acoust. Soc. Am.
122
(
4
),
2306
2319
.
91.
Wagner
,
R. K.
,
Torgesen
,
J. K.
,
Rashotte
,
C. A.
, and
Pearson
,
N. R.
(
2013
).
Comprehensive Test of Phonological Processing
, Second ed. (
Pro-Ed
,
Austin, TX
).
92.
Watson
,
B. U.
, and
Miller
,
T.
(
1993
). “
Auditory perception, phonological processing, and reading ability/disability
,”
J. Speech Lang. Hear. Res.
36
(
4
),
850
863
.
93.
Wickham
,
H.
(
2009
). “
ggplot2: Elegant graphics for data analysis [R package]
,” available at (Last viewed 5 April 2019).
94.
Wickham
,
H.
(
2016
). “
tidyr: Easily tidy data with ‘spread()’ and ‘gather()’ functions [R package]
,” available at (Last viewed 5 April 2019).
95.
Wickham
,
H.
, and
Francois
,
R.
(
2015
). “
dplyr: A grammar of data manipulation [R package]
,” available at (Last viewed 5 April 2019).
96.
Wong
,
J. W. S.
(
2013
). “
The effects of perceptual and/or productive training on the perception and production of English vowels /ɪ/ and /iː/ by Cantonese ESL learners
,” in
INTERSPEECH
, pp.
2113
2117
.
97.
Wong
,
P. C.
, and
Perrachione
,
T. K.
(
2007
). “
Learning pitch patterns in lexical identification by native English-speaking adults
,”
Appl. Psycholinguist.
28
(
04
),
565
585
.
98.
Wong
,
P. C.
,
Vuong
,
L. C.
, and
Liu
,
K.
(
2017
). “
Personalized learning: From neurogenetics of behaviors to designing optimal language training
,”
Neuropsychologia
98
,
192
200
.
99.
Zandipour
,
M.
,
Perkell
,
J.
,
Guenther
,
F.
,
Tiede
,
M.
,
Honda
,
K.
, and
Murano
,
E.
(
2006
). “
Speaking with a bite-block: Data and modeling
,” paper presented at the
Proceedings of the 7th International Seminar on Speech Production
.
You do not currently have access to this content.